WEDNESDAY MORNING, 20 MAY 2009 GRAND BALLROOM II, 8 ...

WEDNESDAY MORNING, 20 MAY 2009

GRAND BALLROOM II, 8:55 A.M. TO 12:00 NOON Session 3aAA

Architectural Acoustics: Measurement and Modeling of Scattering Effects David T. Bradley, Chair Physics and Astronomy Dept., Vassar College, Poughkeepsie, NY 12604-0745 Invited Papers 8:55 3aAA1. Scattering prediction and measurement in architectural acoustics. David T. Bradley 共Phys. and Astron. Depart., Vassar College, 124 Raymond Ave., Poughkeepsie, NY 12604-0745, [email protected]兲 Reflected sound energy typically exhibits a combination of both specular and diffuse behavior when acoustic waves encounter a solid surface. For specularly reflected sound, the angle of reflection is equal to the angle of incidence. A diffusely reflected sound is characterized by dispersion in both the spatial and temporal domains. The ability of a surface to diffusely reflect sound is characterized by the amount of scattering in its reflected energy, and can be determined using numerical prediction schemes and experimental measurement techniques. Although the study of scattering surfaces plays an integral role in several fields of acoustics, the development of these measurement and prediction procedures is relatively nascent, particularly in the field of architectural acoustics. An overview of the current state-of-the-art for these procedures will be presented along with an outline of possible future directions in this area of research. 9:15 3aAA2. Measurement and modeling of scattering in underwater acoustics: A potential value to architectural acoustics? Martin Siderius 共Dept. of Elect. and Comput. Eng., Portland State Univ., 1900 SW 4th Ave., Portland, OR 97201, [email protected]兲, David Bradley 共Vassar College, Poughkeepsie, NY 12604-0745兲, and Lisa Zurk 共Portland State Univ., Portland, OR 97201兲 Scattering measurement and modeling techniques in underwater acoustics have undergone significant progress through several decades of research. The knowledge gained from this research can be applied to similar scattering problems found in above water systems, such as those typically seen in architectural acoustics. Underwater environments have inherently complex scattering behavior including multiple propagation paths and boundaries that are rough and spatially variable. Additionally, boundaries are often moving, which can introduce different Doppler shifts on multipath arrivals, referred to as Doppler spread. These complications make modeling underwater propagation and scattering a challenging problem. However, there are currently several models that are routinely used for predicting underwater acoustic behavior. In some cases, deterministic modeling can be used while in others the complexity only allows for a statistical description of the acoustic field. In recent years, acoustic communications have emerged as an important ocean application, and the innovations provided by these systems have pushed the limits of current techniques. An overview of these modeling and measurement techniques will be presented, and the lessons learned from recent advances will be reviewed in the context of identifying commonalities between underwater and architectural acoustics. 9:35 3aAA3. Fractal surfaces: Generation and acoustic scattering prediction. Derek R. Olson and David T. Bradley 共Phys. and Astron. Dept., Vassar College, 124 Raymond Ave., Box 2529, Poughkeepsie, NY 12604兲 Typical acoustical diffuser design results in diffuse sound scattering only for a limited frequency band, which is problematic given the breadth of the human audible frequency range. Surfaces exhibiting fractal geometries may address this problem due to their selfsimilarity over multiple scales. Stochastic fractals, such as the random midpoint displacement 共RMD兲 fractal, are well-suited to this usage since they can be mapped onto physical surfaces appropriate for acoustical diffusers. In the current project, virtual RMD fractal surfaces were generated and then constructed using a 3-D printer. A pilot study has been conducted to determine the scattering properties of the fractal surfaces using a numerical prediction scheme carried out using the boundary element method 共BEM兲. Experimental measurements of the scattering properties were also carried out according to ISO 17497. The numerical predictions and experimental measurements were contrasted to improve numerical prediction accuracy and optimize the fractal design parameters of acoustical diffusers. These parameters include surface roughness, fractal dimensionality, number of iterations, and the random number probability distribution function. The comparison of the numerical and experimental results will be presented along with effects of the fractal design parameters. 9:55 3aAA4. A suggested method to be used to measure the scattering coefficient of full-scale samples. Ron Sauro 共NWAA Labs., Inc., 25132 Rye Canyon Loop, Santa Clarita, CA 91355, audioគ[email protected]兲 In attempting to follow ISO 17497-1 as a method for measuring full-scale scattering coefficients, it was observed that many of the recommended steps needed to be modified for those full-scale measurements. Variations were tried to aid in these measurements. These variations are described and suggested solutions to the problems observed are presented. It was observed that continuous rotation of the sample, rather than step action rotation, worked better for taking consistent data from the sample. A stable chamber environment is also necessary with humidity reaching at least 50% and temperature variations should not vary by more than 1°C throughout all four parts 2613

J. Acoust. Soc. Am., Vol. 125, No. 4, Pt. 2, April 2009

157th Meeting: Acoustical Society of America

Downloaded 22 Nov 2012 to 188.37.181.82. Redistribution subject to ASA license or copyright; see http://asadl.org/terms

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of the test. It was also observed that a less directional source than recommended was needed so two dodecahedron loudspeakers were chosen to reproduce a combined weighted noise stimulus source. Six data microphones were placed at random locations and varying heights to collect data. Data were compared between the suggested method and the ISO-17497-1 standard. 10:15—10:30 Break

Contributed Papers 10:30 3aAA5. Investigating multifractals to quantify diffuseness in rooms. Noel W. Hart 共Graduate Prog. in Archit. Acoust., Rensselaer Polytech. Inst., 2403 21st St. Apt. 5, Troy, NY, 12180, [email protected]兲 and Ning Xiang 共Rensselaer Polytech. Inst., Troy, NY, 12180兲 Diffuseness, an important room acoustics parameter, currently has no accurate objective method of quantification. Most methods that claim to be able to quantify it require specialized equipment or guesswork. Multifractals present a recent method that allows diffuseness in rooms to be quantified by analyzing a single room impulse response 关Loutridis, JASA 125共3兲共2009兲兴. This method will be verified by acoustical measurements in rooms of various degrees of diffuseness. Since this method has only been demonstrated in small rooms, its applicability towards larger rooms of different types is tested. Frequency dependency is also unknown and is investigated.

10:45 3aAA6. Prediction and tailoring of steady-state broadband sound fields in enclosures using absorption scaling and energy-intensity boundary elements. Donald Bliss, Krista Michalis, and Linda Franzoni 共Mech. Eng. and Mater. Sci., Duke Univ., Durham, NC 27708, [email protected]兲

sound arrive at the receiver in close succession when measuring low incident angles, special processing must be exercised in order to resolve the relationship between the sounds. This research addresses the challenges of the goniometer measurement and attempts to use a synthesized aperture goniometer to derive accurate diffusion and directivity properties of materials. 11:15 3aAA8. Measurement and improvement of the diffuse-reflection coefficients of profiled-wood surfaces. Chris Bibby and Murray Hodgson 共Acoust. & Noise Res. Group, SOEH-MECH, Univ. of British Columbia, 3rd Fl., 2206 East Mall, Vancouver, BC, V6T 1Z3 Canada兲 An apparatus and procedure were developed for measuring the diffusereflection coefficients of surfaces in an anechoic chamber according to the ISO-17497 method. This involves determining the proportion of incoherent energy in the impulse response measured in the presence of the surface. Surface absorption was measured by the reverberation-room method. The sound-absorption and sound-diffusion properties of two existing profiledwood architectural panels, one with sinusoidal corrugations, the other comprising rectangular sections of different heights, were characterized. Investigations into how to improve the absorption and diffusion characteristics were made, and prototype surfaces tested and evaluated.

Enclosures with diffuse reflection boundaries are modeled with an energy-intensity boundary element method using uncorrelated broadband directional sources. An absorption-based perturbation analysis shows the spatial variation of acoustic field obeys certain scaling laws. A series expansion in terms of average absorption gives separate boundary integral problems at each order. The lowest-order solution has a uniform level proportional to the reciprocal of the average absorption. The next-order solution is independent of average absorption and primarily responsible for spatial variation of the acoustic field. This solution depends on the spatial distribution of absorption and input power sources, but not their overall level. For the primary spatial variation, the effects of the relative distributions of absorption and input power are linear and uncoupled. These distributions can be expressed in terms of constituent spatial modes corresponding to the ways absorption and input power can be distributed. Solved numerically once for each mode, the acoustic field can be expressed in terms of the modal amplitudes in closed form. These amplitudes can be adjusted to tailor the spatial variation. Examples include how to distribute absorption to minimize sound levels in one location, or how to achieve a uniform interior field. 关Sponsor: NSF.兴

This study investigates an in-situ measurement method to evaluate the diffuseness of a sound field using scale model concert halls. The diffusers were applied to scale model concert halls in which the impulse responses at both the audience and stage area were observed. Both reflection number 共RN兲 and reflection energy 共RE兲 were used as in-situ diffusivity indices: RN is defined by the number of reflection rays of which critical amplitude level is within ⫺30 dB after the direct sound, and RE defined by the integrated energy at the normalized impulse responses. Through the scale model measurements, it was observed that half of the side walls near the stage were effective for diffuseness of sounds both in auditorium and on stage. It was also found that the balancing of in-situ diffusivity is useful for diffuseness perception, which is subject to the level of the direct sounds.

11:00 3aAA7. Measuring the uniform diffusion coefficient: Synthesized aperture goniometer measurements. Philip W. Robinson, Ning Xiang 共Architectural Acoust. Program, Rensselaer Polytechnic Inst.兲, and Peter D’Antonio 共RPG Diffusor Systems, Inc.兲

11:45 3aAA10. Measurement of diffuse sound reflection from an impedance surfaces using one microphone by bayesian inversion. Gavin Steininger 共Acoust. and Noise Control Res. Group–Dept. of Mech. Eng., Univ. of British Columbia, Vancouver, BC, Canada兲 and Murray Hodgson 共Univ. of British Columbia, Vancouver, BC, Canada兲

There are currently two methods to measure the diffusion/scattering from acoustical surfaces: reverberation chamber measurement and in-situ measurement using a semicircular array of microphones called a goniometer. Each of these methods has advantages and drawbacks. The reverberation chamber method accounts for random incidence, but produces inconsistent results for materials of the same profile but different absorption. It does not distinguish between one-dimensional and two-dimensional surface topologies, since the sample is rotated, and is also inapplicable to high absorption materials. The goniometer measurement quantifies directivity as well as diffusion, but presents challenges related to processing power, as many microphones are required to achieve reasonable resolution. Using a procedure akin to synthesized aperture radar, a 2.5° resolution polar plot of the 180° response is achieved by scanning eight microphones rather than employing a full array of 72. Also, since the direct sound and reflected

This paper discusses the use of inverse methods to find the absorption and diffusion characteristics of surfaces. An impedance surface in an anechoic chamber is excited by a pure tone source above it. The steady-state sound level is measured at n points above the impedance surface. The distribution of the n steady-state sound-pressure levels is assumed to be Gaussian. The set of mean or predicted values for this distribution is generated by finding the modulus of a modified Sommerfeld boundary element solution to the Helmholtz equation. The modification is to add multiple diffusely reflected waves each of which is additionally attenuated by a distribution that is proportional to sin共2␪兲⫻G共␪兲D␪⫻H共␾兲D␾, where G共␪兲 is the piecewise function 关G共␪兲⫽␪/␪Spec, ␪艋␪Spec, and 关共␲/2兲⫺␪兴/关共␲/2兲⫺␪兴Spec otherwise兴 and H共␾兲⫽兩共1⫺␾兲/␲兩. The system of equations is then optimized for the specific impedance of the surface, the normal diffusion coefficient, and the azimuth diffusion coefficient 共Z, D␪, and D␾兲 using Bayesian

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11:30 3aAA9. An in-situ diffusivity measurement method for diffuser design in concert halls. Jin Yong Jeon and Yong Hee Kim 共Dept. of Architectural Eng., Hanyang Univ., Seoul 133-791, Korea兲



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inversion. This process is repeated for two surfaces 共painted plywood over 16 inch studs and painted plywood over 16 inch studs with randomly placed

wooden blocks兲 at six frequencies 共250, 500, 1000, 2000, 4000, and 8000 Hz兲.


GALLERIA NORTH, 8:00 TO 11.45 A.M. Session 3aAB

Animal Bioacoustics and Acoustical Oceanography: Autonomous Remote Monitoring Systems for Marine Animals III Marc O. Lammers, Chair Hawaii Inst of Marine Biology, Kailua, HI 96734 Invited Papers 8:00 3aAB1. From mysticete song to odontocete echolocation: Monitoring cetacean sounds with high-frequency acoustic recording packages (HARPs). Sean M. Wiggins and John A. Hildebrand 共Scripps Inst. of Oceanogr., 9500 Gilman Dr. La Jolla, CA 92093-0205, [email protected]兲 Marine mammals produce a wide range of sounds from 10s of Hz to 100s of kHz. To remotely monitor these various sounds with autonomous systems, instruments with wide bandwidths are required. A general purpose, autonomous, high-frequency acoustic recording package 共HARP兲 is described that can record sounds ranging from low-frequency blue whale 共Balaenoptera musculus兲 song to mid-frequency dolphin whistles and beaked whale sweeps to high-frequency dolphin clicks. In addition to monitoring marine mammals, sounds from fish, contributions from wind and rain, and anthropogenic sources such as ships and sonar also are recorded potentially allowing for the study of cetacean behavioral response to these sounds. HARPs have been deployed for periods of up to one year, in various configurations such as standard moorings, seafloor packages, and arrays, and in remote locations including the Arctic, Bering Sea, Gulf of California, around Hawaii, and offshore of Washington State and southern California. The various configurations of these deployments and the wide range of marine mammal monitoring data they have provided are discussed in addition to lessons learned from these studies. 关Work supported by the U.S. Navy CNO-N45.兴 8:20 3aAB2. Extending passive acoustic capabilities of autonomous recorders by using multiple hydrophones. Aaron Thode, Robert Glatts 共Marine Phys. Lab., Scripps Inst. of Oceanogr., 9500 Gilman Dr., San Diego, CA 92109-0238兲, and William C. Burgess 共Greeneridge Sci. Inc., Goleta, CA 93117兲 Low-power data acquisition systems have attained sampling rates large enough to enable multielement hydrophone arrays to be deployed autonomously, at the cost of reducing the individual sampling rate per phone. This paper discusses what theoretical advantages bandlimited multielement recordings can provide over single-hydrophone data, including array gain for increased detection range, interfering noise source rejection, environmental inversion, and biological source tracking. These points are illustrated with data collected from an autonomous four-element vertical array off Queensland, Australia in 2003, and data collected from an autonomous eightelement, 21 m aperture vertical array deployed at 35 m depth in the Beaufort Sea in 2008. These examples also provide insight into the technical and logistical challenges required by such deployments, including deployment and recovery systems that do not endanger or entangle array cables. 关Work supported by NPRB, logistics provided by Greeneridge Sciences and Shell Co.兴

Contributed Papers 8:40 3aAB3. An autonomous, near-real-time buoy system for automatic detection of North Atlantic right whale calls. Eric Spaulding, Matt Robbins, Tom Calupca, Christopher Clark, Tremblay Tremblay, Amanda Waack, Ann Warde 共Bioacoust. Res. Prog., Cornell Univ., 159 Sapsucker Woods Rd., Ithaca, NY 14850兲, John Kemp, and Kristopher Newhall 共Woods Hole Oceanograph. Inst., Woods Hole, MA 02543兲 A moored buoy system for automatic detection of endangered North Atlantic right whale 共NARW兲 upcalls was developed to provide near-real-time information on the presence of whales. The marine components include the WHOI buoy platform 共mooring, hydrophone, power system, surface expression, and antennae兲 and Cornell buoy electronics 共housing, analog interface hardware, GPS, embedded computer, detection engine, and telemetry hardware兲. Shore-side Cornell components include telemetry equipment,

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server hardware and processing software, database, and interfaces for data annotation, access, and visualization. The buoy hardware/software system is capable of capturing and ranking NARW upcall candidates as 2 s, 2000 Hz sampled audio clips. GPS location, timestamp, and other metadata associated with each audio clip are bundled together and uploaded via satellite for processing. Human analysts regularly annotate incoming data, resulting in a curated database of NARW detections. Periodic “health and status” data allow for confirmation that buoys are functional. Regular voltage reporting helps predict required maintenance. Following initial implementations of the system in 2005, a series of successes and failures have led to system improvements. Deployments have progressed from prototype near-shore units to an operational network continuously monitoring the shipping lanes off Boston to meet ship strike mitigation requirements. Upcoming features and capabilities will be discussed.



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8:55 3aAB4. Right whale gunshot calls in the southeastern Bering Sea. Catherine L. Berchok, Laura J. Morse, Phillip J. Clapham 共Natl. Marine Mammal Lab., NOAA/AFSC, 7600 Sand Point Way NE, Seattle, WA 98115-6349, [email protected]兲, Holger Klinck, Karolin Klinck, David K. Mellinger 共Oregon State Univ. & NOAA Pacific Marine Environ. Lab., Newport, OR 97365兲, Donald K. Ljungblad 共Marine Acoust. Consultants, LLC, Elk Mountain, WY 82324-0006兲, Sue E. Moore 共NOAA/S&T-PMEL, Seattle, WA 98115-6349兲, Francesco Scattorin 共Universita di Pavia, 27100 Pavia, Italy兲, and Jennifer L. Keating 共Zoological Society of San Diego, San Diego, CA 92112-0551兲

likely that this population now numbers in the tens of animals. Little is known about the distribution, movements, migrations, or habitat use of this population, but the existing data suggest that it now occupies a reduced range compared to historical times. In 2007, NMML began conducting a multiyear study of the distribution, abundance, and habitat use of North Pacific right whales in the North Aleutian Basin and southeastern Bering Sea using aerial and vessel surveys. During the 2008 survey, directional sonobuoys were used 24 h a day to record right whale calls and obtain crossbearings to the whales. Although previous work in the Bering Sea focused on detections of the right whale upsweep call, our findings suggest that the gunshot call is much more ubiquitous. Spatial and temporal trends of gunshot calls will be presented, and changes in gunshot call characteristics relative to observed surfacing sequences will be described. 关Work supported by an interagency agreement from the Minerals Management Service.兴

The eastern population of the North Pacific right whale 共Eubalaena japonica兲 is critically endangered. Following extensive historical whaling in the 19th century and large illegal catches by the USSR in the 1960’s, it is

Invited Paper 9:10 3aAB5. Environmental acoustic recording system (EARS) buoys for marine animal acoustics. George E. Ioup, Juliette W. Ioup, Arslan M. Tashmukhambetov, Lisa A. Pflug 共Dept. of Phys., Univ. of New Orleans, New Orleans, LA 70148, [email protected]兲, Joal J. Newcomb 共Stennis Space Ctr., MS兲, Natalia A. Sidorovskaia 共Univ. of Louisiana at Lafayette, Lafayette, LA兲, Stan A. Kuczaj, Grayson H. Rayborn, James M. Stephens 共Univ. of Southern Mississippi, Hattiesburg, MS兲, Christopher O. Tiemann, and Alan Bernstein 共Univ. of Texas at Austin, Austin, TX兲 EARS buoys were developed as autonomous, moored, underwater recording systems by the Naval Oceanographic Office 共NAVOCEANO兲 to make long-term ocean ambient noise measurements. When the Littoral Acoustic Demonstration Center 共LADC兲 was formed as a consortium of university and U.S. Navy scientists in 2001, the buoys were capable of measuring up to 1000 Hz for 1 yr. LADC added listening to sperm whales to its noise and propagation measurements. NAVOCEANO quickly modified the buoys to measure up to 5859 Hz for 36 days. The buoys, moored at depths from 550 to 950 m in the Gulf of Mexico, produced exceptionally clear recordings of sperm whale echolocation and coda clicks and recordings of other whales. EARS Generation 2 buoys are now capable of recording one channel to 96 kHz, or four channels to 25 kHz, for more than 13 days on four 120 Gbyte notebook disk drives. Experiments in the Gulf of Mexico and the Ligurian Sea have targeted both sperm and beaked whales. Audio results and visualizations of these recordings reveal rich detail of Odontocete clicks and enable new analyses, such as the identification of individual whales from the properties of their clicks. 关Research supported by ONR and SPAWAR.兴

Contributed Paper 9:30 3aAB6. Localization to verify the identification of individual sperm whales using click properties. Juliette W. Ioup, George E. Ioup, Lisa A. Pflug, Arslan M. Tashmukhambetov 共Dept. of Phys., Univ. of New Orleans, New Orleans, LA 70148, [email protected]兲, Christopher O. Tiemann, Alan Bernstein 共Univ. of Texas at Austin, Austin, TX兲, Natalia A. Sidorovskaia, Philip Schexnayder 共Univ. of Louisiana at Lafayette, Lafayette, LA兲, Joal J. Newcomb 共Stennis Space Ctr., MS兲, Stan A. Kuczaj, Grayson H. Rayborn 共Univ. of Southern Mississippi, Hattiesburg, MS兲, and Rowena M. Carlson 共SPAWAR Systems Ctr. Pacific, San Diego, CA兲

these identifications has previously been available. However, data from a July 2007 experiment in the Gulf of Mexico should provide enough geometry information to verify some identifications. The Littoral Acoustic Demonstration Center deployed six environmental acoustic recording system buoys, measuring to 96 kHz for 9 days, to record sperm and beaked whale clicks in the northern Gulf of Mexico. Three buoys were in close proximity to enable multisensor detections of single clicks for possible localization, tracking, or bearing estimation sufficient to confirm the identification of individuals from cluster analysis. Displays of cluster classifications versus time coupled with location estimates for the clicks give evidence of the accuracy of the identifications. Though localization serves to verify the classification tool, click identification complements localization by separating sounds from multiple sources when several whales’ clicktrains overlap, potentially enabling previously impossible tracking. 关Research supported by SPAWAR and ONR.兴

Previous research to identify individual sperm and beaked whales from the properties of their echolocation and coda clicks using cluster analysis has been reported. Although reasonably consistent and robust results showing distinct classes 共each corresponding to an individual兲 have been obtained with both self-organizing maps and K-means, no independent verification of

Invited Papers 9:45 3aAB7. Detection of killer whale presence using low duty cycle recorders. Jeffrey A. Nystuen 共Appl. Phys. Lab., Univ. of Washington, 1013 NE 40th St., Seattle, WA 98105, [email protected]兲, M. Bradley Hanson, Candice Emmons 共NOAA Northwest Fisheries Sci. Ctr., Seattle, WA兲, Paul Wade 共NOAA Alaska Fisheries Sci. Ctr., Seattle, WA兲, and Jennifer Miksis-Olds 共Penn State Univ., State College, PA兲 Passive aquatic listeners 共PALs兲 have been developed to make long-term 共up to a year兲 autonomous measurements of the underwater ambient noise in the marine environment. Because of data storage limitations and low-power requirements, PALs have a very low duty cycle, of the order of 1 percent. In fact, they are optimized for acoustic rainfall detection and have been successfully used to measure wind speed and rainfall rate at sea using spectral components of the sound field. These geophysical sounds have relatively long time scales 共minutes兲 compared to vocalizations of marine mammals 共seconds兲 or mooring noise 共chain clanking兲. Data collection was designed to detect and reject short temporal signals. However, these signals include marine mammal vocalizations. Consequently, the sampling strategy was modified to evaluate the temporal content of the data sample and save the temporal data sample only if it contains 2616




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a signal consistent with killer whale vocalizations. These sound bites have demonstrated detection of pod-specific vocalizations of resident-type killer whales, transient-type killer whales, bone crunching from likely killer whale predation 共eating兲 on sea lions, and humpback and N. Pacific right whales. 10:05—10:25 Break 10:25 3aAB8. Managing the passive acoustics data deluge. David A. Mann 共Coll. of Marine Sci., USF, 140 7th Ave. S., St. Petersburg, FL 33701, [email protected]兲 Passive acoustic recording systems can generate large amounts of data, especially given the increasing availability of inexpensive flash memory. Thus it is easy to collect more data than can be efficiently analyzed. One approach to this problem is to minimize data collection on the recorder by performing real-time automated detection of acoustic targets of interest. An alternate approach, where one does not know what signals may be present, is to record large amounts of data over extended periods of time. DSGlab is an open-source database and data analysis system implemented with MATLAB that is designed to manage large amounts of raw data. The database aspect of the program allows querying of data by latitude, longitude, depth 共or altitude兲. Each recorded data file is tagged with header information including lat/lon/depth, timestamp, sample rate, and calibration. The data analysis section processes the files according to a user-specified signal processing chain, which does not require a knowledge of programming to generate, and returns results to a database and to individual files. The results of signal processing can then be quickly browsed with the data viewer. The system is designed to allow inter-laboratory collaboration and data sharing.

Contributed Papers 10:45 3aAB9. Acoustic rediscovery of right whales in a former whaling area, the Cape Farewell Ground, between Greenland and Iceland. David K. Mellinger, Sharon L. Nieukirk, Karolin Klinck, Holger Klinck, Robert P. Dziak 共Cooperative Inst. for Marine Resources Studies, Oregon State Univ. and NOAA Pacific Marine Environ. Lab., 2030 SE Marine Sci. Dr., Newport, OR 97365兲, and Phillip J. Clapham 共NOAA Natl. Marine Mammal Lab., Seattle, WA 98115兲

of sound production in SRKWs. We collected behavioral and acoustic data simultaneously over two field seasons and found that click occurrence as well as calling rates 共calls/whale/min兲 were significantly higher when whales were foraging compared to traveling. Such patterns are useful for inferring events from remote acoustic monitoring. These results also indicate that communicative signals are particularly important during foraging activities in this population and have implications for noise disturbance.

The North Atlantic right whale 共Eubalaena glacialis兲 is one of the world’s most endangered cetaceans, with only 300–350 animals believed alive. Most right whales are thought to range from Florida to Nova Scotia, though the whereabouts of a significant portion of the population remains unknown in both winter and summer. Here we describe an acoustic survey for right whales near the Cape Farewell Ground, a late 18th-century whaling area. Continuously recording autonomous hydrophone instruments were deployed at five sites for one year in 2007–2008, after which data were analyzed by automatic detection with manual checking for “up” calls of right whales. Over 2000 calls were detected in all, with calls found at all sites but mostly from near the Cape Farewell Ground. The data are consistent with a seasonal migration northeastward toward Iceland in July–August followed by return movement later in the fall, with the last detection in December. At one site, calling occurred in the fall on 17 separate occasions, suggesting a significant number of right whales present. A right whale photo-identified in 2003 at the Cape Farewell Ground was not in the North Atlantic right whale catalog, suggesting the possibility of a previously unidentified stock.

11:15 3aAB11. Simultaneous acoustic tag and seafloor acoustic recorder detection of right whale calls in the Bay of Fundy. Susan E. Parks 共Appl. Res. Lab., The Penn State Univ., P.O. Box 30, State College, PA 16804兲, Christopher W. Clark 共Cornell Univ., Ithaca, NY 14850兲, Mark Johnson, and Peter L. Tyack 共Woods Hole Oceanograph. Inst., Woods Hole, MA 02543兲

11:00 3aAB10. Sound production and behavior in an eastern North Pacific killer whale population: Implications for autonomous remote monitoring. Marla M. Holt, Dawn P. Noren, Candice K. Emmons 共Marine Mammal Program, NOAA/NMFS Northwest Fisheries Sci. Ctr., 2725 Montlake Blvd. East, Seattle, WA 98112, [email protected]兲, and AnnaMaria Seibert 共Univ. of Munich, Planegg-Martinsried, 82152 Germany兲 Remote acoustic monitoring is often used to determine the seasonal and spatial distributions of vocal animals, particularly when conditions of other monitoring approaches are limited. Additionally, sound production patterns might be used to infer important activities of free-ranging animals in the absence of other cues. Animals produce sounds during activities such as foraging and breeding, but such patterns are expected to vary between species /populations that are based on a variety of ecological factors. For example, fish-eating killer whales are more vocally active than mammal-eating killer whales, presumably since mammalian prey are sensitive to killer whale sounds. Southern Resident killer whales 共SRKWs兲 are a fish-eating population found in coastal waters of Washington State and British Columbia. The goal of this study was to extend previous work on the behavioral correlates 2617


Passive acoustic monitoring is playing a growing role in marine mammal detection. Determining the range of detection for calls of a particular species in a particular location is important to assess the regional coverage provided by individual recording units. This study describes the comparison of right whale calls recorded by digital acoustic recording tags 共Dtags兲 attached with suction cups to North Atlantic right whales and the detection of the same calls using a dispersed seafloor array of autonomous recorders. The seafloor array consisted of 5 units, spaced 6–10 km apart, continuously recording from July 29– August 17, 2005. Dtags were attached to a total of 14 individual right whales during this time period and 7 of these individuals produced a total of 88 tonal calls during tag attachment. The tag and related tracking of the whale provided information on call type, and the timing, depth, and approximate location of the whale producing the call. Tagged whale calls were audible on the seafloor array, and whale-recorder distances provided estimates of the acoustic detection range for right whales in the Bay of Fundy, Canada. 11:30 3aAB12. Annual variability of cetacean occurrence along the northeast coast of Iceland measured using ecological acoustic recorders. E.E. Magnusdottir, M.H. Rasmussen 共Husavik Res. Ctr., Univ. of Iceland, Hafnarstett 3, 640 Husavik, Iceland, [email protected]兲, and M.O. Lammers 共Hawaii Inst. of Marine Biology, Kailua, HI 96834兲 In order to continuously monitor the annual density and habitat use of cetacean species at the NE coast of Iceland, we deployed two seabed mounted ecological acoustic recorders 共EARs兲 in Skjalfandi Bay 共66 deg 05 .929 N, 17 deg 25.262 W; 66 deg 03.070 N, 17 deg 39.811 W兲. The EAR is a microprocessor-based autonomous recorder. Each EAR was programmed to record for 1 min every 15 min. Both EARs will be retrieved every 3–5 months during a 1-year period. A custom Matlab program will be used to automatically detect and analyze target sounds. Target biological sounds re157th Meeting: Acoustical Society of America


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corded are primarily those produced by cetaceans and also by pelagic fish. Blue whales 共Balenoptera musculus兲, humpback whales 共Megaptera novaeangliae兲, minke whales 共Balaenoptera acutorostrata兲, white-beaked dolphins 共Lagernorhynchus albirostris兲, and killer whales 共Orcinus orca兲 are well known to visit Skjalfandi Bay. In addition, it has been suggested that

cod 共Gadus morhua兲 is spawning in the bay in spring time. The results could reveal annual variability of inter- and intraspecies density of cetaceans and prey within the area. Acoustic monitoring may be an effective means of tracking diurnal and annual activity of cetaceans in a long-term manner and compare the activity to the presence and behavior of prey.


BROADWAY I/II, 8:30 TO 11:15 A.M. Session 3aAO

Acoustical Oceanography and Underwater Acoustics: Environmental Inferences in Inhomogeneous Ocean Environments II Mohsen Badiey, Chair College of Marine and Earth Sciences, Univ. of Delaware, Newark, DE 19716-3501 Chair’s Introduction—8:30

Contributed Papers 8:35 3aAO1. Information theory application to inversions of acoustic data from a continental shelf environment. David P. Knobles, Robert A. Koch, and Jason D. Sagers 共Appl. Res. Labs., The Univ. of Texas at Austin, P.O. Box 8029, Austin, TX 78713兲 This research examines the uncertainty in waveguide parameter values obtained from acoustic inversion of data collected in range-dependent environments. To account for range-dependence in the environmental parameters, the number of inversion parameters must be increased. Generally, from a fixed data sample the uncertainty in the solution for individual parameter values increases as the number of inversion parameters increases, especially if the structure of the propagated acoustic field is sensitive to the additional parameters. This effect can be offset by prior information that reduces the volume of the parameter search space and to a limited extent by larger inversion data samples. How an inversion algorithm accounts for prior information is thus an essential issue to be addressed for rangedependent waveguides. Measurements made on the New Jersey shelf in 70–90 m of water provide an opportunity to study the effects of environmental range dependence on sound propagation and inversion processing. Inversions based on pre-existing geophysical information are combined with a maximum entropy approach to quantify the amount of information on the waveguide parameters that can be extracted from measured propagation over range-dependent tracks. Both towed sources emitting CW lines and impulsive sources are employed. 关Work supported by ONR.兴

mulation shows more robustness for larger variability. The relative merits of PC expansions for the complex modal amplitudes vs the log amplitudes for the complex pressure amplitudes are also discussed. 9:05 3aAO3. Resolving spatial seabed variability by Bayesian inference of seabed reflection inversions. Jan Dettmer, Stan E. Dosso 共School of Earth and Ocean Scinces, Univ. of Victoria, Victoria, BC V8W 3P6, Canada兲, and Charles W. Holland 共The Penn State Univ., State College, PA兲 This paper considers Bayesian inversion of seabed reflection-coefficient data for multilayer geoacoustic models at several sites with the goal of studying spatial variability of the seabed. Rigorous uncertainty estimation is of key importance to resolve spatial variability between measurement sites from the inherent inversion uncertainties. Geoacoustic uncertainty estimation is carried out including Bayesian model selection and comprehensive estimation of data error statistics. Model selection is addressed using the Bayesian information criterion to ensure parsimony of the parametrizations. Data error statistics are quantified by estimating full covariance matrices from data residuals, and a posteriori statistical validation is carried out. A Metropolis-Hastings sampling algorithm is used to compute posterior probability densities. Five experimental sites are considered along a track located on the Malta Plateau, Mediterranean Sea, and the inversion results are compared to cores and subbottom profiler sections. Differences between sites that exceed the estimated geoacoustic uncertainties are interpreted as spatial variability of the seabed.

8:50 3aAO2. Probability density functions of modal amplitudes and complex acoustic pressure in fluctuating shallow water waveguides. Kevin D. LePage 共NATO Undersea Res. Ctr., Viale San Bartolomeo 400, 19126 La Spezia, Italy兲

9:20 3aAO4. A simplified model of frequency distortion in ocean acoustic signals by multiple interactions with a moving ocean surface and its use in oceanographic inversions. Stephen D. Lynch and Gerald L. D’Spain 共Marine Physical Lab., Scripps Inst. of Oceanogr., 9500 Gilman Dr. 0701, La Jolla, CA 92093-0701兲

The polynomial chaos method is applied to the problem of predicting the probability density functions of complex modal amplitudes and acoustic pressure in the presence of water column sound speed fluctuations in shallow water waveguides. Results for both the intrusive implementation of the polynomial chaos technique, where the governing coupled mode differential equations for the complex modal amplitudes are augmented with the random states of the chaos expansion, and the non-intrusive method, where legacy codes can be run over an ensemble of ocean realizations and the results fitted by a truncated chaos expansion, are shown. Both methods give good agreement with Monte Carlo histograms of the modal amplitudes and the pressure field for slight water column variability, but the non-intrusive for-

Received omnidirectional spectra of low frequency narrowband tones measured in a shallow ocean waveguide exhibit Doppler-shifted sidebands at frequencies whose offsets are integer multiples of the dominant surface wave frequencies. These observations suggest that higher order scattering is important. However, higher-order perturbation theory involving only a single surface interaction does not predict the observed relative sideband levels. In particular, the higher order sidebands were often observed to increase in relative level to the main spectral peak during smaller surface wave, and, therefore, smaller kh, conditions. A simplified model is presented that simulates the surface wave-induced frequency distortions as path-length modulation caused by the vertical motions of the surface. The model incor-

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porates multiple interactions with the moving surface, and quantitatively predicts the effects on the received spectra of the spatial coherence of the surface waves along the propagation path. The model results are identical to those from higher order perturbation with a single interaction. The simplified nature of this model allows it to be readily used to invert for various properties of the ocean surface wave directional spectrum. 关Work supported by ONR, Code 321共US兲.兴 9:35 3aAO5. Particle filter source tracking in a changing geoacoustic environment. Caglar Yardim, Peter Gerstoft, and William S. Hodgkiss, 共Marine Phys. Lab., 2038 Scripps Inst. of Oceanogr., Univ. of California, San Diego, 9500 Gilman Dr., La Jolla, CA 92093-0238, [email protected]兲 This paper addresses the problem of tracking the acoustic source parameters such as the depth, range, and speed in evolving geoacoustic environments. It is well known that inaccurate knowledge about the environmental parameters such as the sound speed profile 共SSP兲, water depth, sediment, and bottom parameters may result in significant errors in source parameters. To counter this, a particle filtering 共PF兲 approach is adopted here where the geoacoustic parameters are tracked together with the source location and speed in a range-dependent environment. This allows accurate, realtime updating of the environment the ship is moving in and hence source can be located at any time accurately. As a sequential Monte Carlo technique that can operate on nonlinear systems with non-Gaussian probability densities, the PF is an ideal tracking algorithm to perform tracking of source and environmental parameters and their evolving probability distributions. The algorithm is tested on a sloping environment with the SSP, water depth, and sediment parameters evolving as the ship moves. The change in the water depth created the well-known “source mirage effect,” but the PF was still able to track the true source, geoacoustic parameters, and their evolving densities in this spatially varying environment. 关Work supported by ONR.兴 9:50 3aAO6. Statistics of mode amplitudes in shallow water environments: Effects of random linear internal waves and nonlinear internal wave packets. John Colosi 共Naval Postgrad. School, 833 Dyer Rd., Monterey, CA 93943, [email protected]兲, Andrey Morozov, and Tim Duda 共Woods Hole Oceanograph. Inst., Woods Hole, MA 02543兲 In shallow water environments there is presently an incomplete understanding of the relative acoustical importance of the random linear internalwave field compared to nonlinear internal waves packets. Using the random coupled mode theory of 关Creamer 共1996兲兴, the nonlinear internal wave mode coupling theory of 关Colosi 共2007兲兴, and Monte Carlo numerical simulation we are able to demonstrate the important propagation physics when the two internal wave fields act alone, and simultaneously. Importantly, we find that for acoustic frequencies less than roughly 500 Hz and for propagation ranges of order 10s of kms mode propagation though the random internal wave field is very nearly adiabatic, and that cross mode coherences decay rapidly within the first 10 km. A surprising consequence of the decay of cross mode coherence is that the mean intensity will be to first order insensitive to nonlinear internal wave packets if they are located past the decoherence range. It will also be shown that uncorrelated modes have important implications for the approach to saturation. The adiabatic nature of mode propagation though the random internal wave field may have important implications for shallow water acoustic remote sensing. 10:05—10:30 Break 10:30 3aAO7. Inversion for range-dependent water column sound speed profiles in shallow water. Megan S. Ballard 共Graduate Program in Acoust., Penn State, P.O. Box 30, State College, PA 16804-0030, [email protected]兲 and Kyle M. Becker 共Penn State, State College, PA 16804-0030兲

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Spatial and temporal variability of the sound speed field in the water column can have a significant impact on acoustic propagation. It is difficult or sometimes impractical to measure fine scale variations in water column properties over an acoustic propagation path. When measurements are not available, water column properties must be approximated. In past work, inverse methods based on acoustic tomography and matched-field processing have been used to estimate mean water column sound speed profiles. The drawback of these methods is their inability to capture fluctuations in the water column sound speed profile. In this work, a perturbative scheme using modal wave numbers is used to obtain range-dependent features of the water column. Based on the work of Rajan et al. 共1987兲, a technique has been developed to estimate water column sound speed profiles using historical data to constrain the inversion. This constraint allows for a robust inversion; the result is accurate both when the inputs are noisy and when the bottom is poorly known. The new technique is demonstrated using data from the Shallow Water 2006 共SW06兲 experiment. Inversion results are compared to in situ measurements from the towed CTD chain. 关Work supported by NDSEG and ONR.兴

10:45 3aAO8. The estimation of geoacoustic parameters via low frequencies (50–75 Hertz) for simulated shallow water test scenarios. A. Tolstoy 共ATolstoy Sci., 1538 Hampton Hill Circle, McLean, VA 22101兲 This work will demonstrate the success of using only a variety of low frequencies 共50–75 Hz兲 for geoacoustic inversion in simulated SW06 environments. The environments include a variety of scenarios 共a thin, medium, or thick sediment layer over a half-space兲, broadband sources at approximately 1 km range 共rge兲, and a vertical array consisting of 16 phones whose depths are approximately known, i.e., we assume that array element localization was available so that we can estimate phone depths 共zphi兲 to within about 1 m. The source depths 共zsou兲 and water depths 共D兲 are approximately determined via time domain crossings seen at the array 关see A. Tolstoy, J. Acoust. Soc. Am. 123, 3106 共2008兲兴. Additionally, the ocean sound-speed c共z兲 is assumed to be range-independent and approximately known, e.g., via measurements or archival data. The use of only the 50–75 Hz portion of the signal results in a need for less than perfect accuracy for zphi and c共z兲 while still giving excellent accuracy for estimated bottom parameters. Geometric parameters 共such as rge, zsou, D, zphi兲 and c共z兲 would be more accurately determined by means of higher frequencies but this would require much more CPU time. Uniqueness of the final “solution” is achieved for all but the thin sediment scenario.

11:00 3aAO9. Detection and classification of typhoons using underwater acoustic sensors in the western Pacific Ocean. Barry Ma 共Dept. of ECE, Portland State Univ., 1900 SW 4th Ave., Portland, OR 97201, [email protected]兲 and Y. J. Yang 共Naval Acad., Tsoying, Kaohsiung, Taiwan兲 About two years of underwater ambient noise were collected using Passive Aquatic Listeners 共PALs兲 in the western Pacific Ocean. PALs were deployed using the bottom-mount or surface-mount buoys on the possible typhoon paths. Several episodes of intensive typhoon noise were recorded during the passage of these powerful tropical storms. These acoustic data are compared with other ancillary data for the classification of typhoons. Using the underwater ambient noise to classify the intensity of typhoons is a relatively reliable method. The instrument is placed away from the air-sea interface in a less destructible environment and provides relative in situ measurement of the wind speed. The ambient noise recordings from the deployment also include the biology, shipping, and other surface noises, but the noises from the typhoons are the most distinguishable against all other sources of noise. The noise budgets from different deployment sites are also presented.



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PAVILION EAST, 8:00 TO 11:45 A.M. Session 3aBB

Biomedical Ultrasound/Bioresponse to Vibration and Physical Acoustics: Shock Wave Therapy I Michael R. Bailey, Cochair Applied Physics Lab., Univ. of Washington, Seattle, WA 98105 Thomas J. Matula, Cochair Applied Physics Lab., Univ. of Washington, Seattle, WA 98105-6698 Invited Paper 8:00 3aBB1. Investigation of an ultrasound imaging technique to target kidney stones in lithotripsy. Anup Shah 共Dept. of Urology, Univ. of Washington School of Medicine, 1959 NE Pacific St., Box 356510, Seattle, WA 98195, [email protected]兲, Marla Paun, John Kucewicz 共Univ. of Washington, Seattle, WA 98105兲, Oleg A. Sapozhnikov 共Moscow State Univ., Moscow 119992, Russia兲, Manjiri Dighe 共Univ. of Washington School of Medicine, Seattle, WA 98195兲, Hunter A. McKay 共The Polyclinic, Seattle, WA 98122兲, Mathew D. Sorensen 共Univ. of Washington School of Medicine, Seattle, WA 98195兲, and Michael R. Bailey 共Univ. of Washington, Seattle, WA 98105兲 Localization of kidney stones and targeting for lithotripsy can be challenges especially with ultrasound. However, twinkling artifact has been observed where Doppler ultrasound imagers assign color to the stone. We report a preliminary investigation from our observations in a porcine model and hypothesize why this artifact occurs. Glass beads, cement stones, and human stones were surgically placed into the renal collecting system through the ureter. The stones were imaged using several transducers and ultrasound imagers. In all cases, the twinkling artifact of the stone was observed, and its appearance and radiofrequency signature were unique from those of blood flow. Calcium oxalate monohydrate stones and smooth stones were not more difficult to image, contrary to previous reports. Increasing gain or placing the focal depth distal to the stone enhanced the artifact, but other user controls showed little effect. Twinkling started at the lateral edges of the stone and spread over the stone as gain was increased. The evidence supports the hypothesis that small motions induced by radiation force or elastic waves in the stone cause changes in received backscatter, particularly at imaging angles oblique to the stone surface. 关Work supported by NIH DK43881 and NSBRI SMST01601.兴

Contributed Paper ⫾1.29% of functional renal volume, P⫽0.006兲. However, slowing the SW rate to 30 SWs/min greatly increases treatment time. Consequently, we investigated whether an intermediate rate of 60 SWs/min also reduces lesion size compared to treatment at 120 SWs/min. Methods: one kidney in 12 juvenile pigs was treated at 120 SWs/min 共n⫽7兲 or at 60 SWs/min 共n⫽5兲 with an unmodified Dornier HM-3 lithotripter 共2000 SWs, 24 kV兲. After lithotripsy, the treated kidneys were fixed and removed to determine lesion size. Results: SWL at 60 SWs/min significantly reduced the size of the morphological lesion compared to 120 SWs/min 共0.42⫾0.23% versus 3.93⫾1.29%, P⫽0.034兲. This reduction in lesion size was comparable to the lesion produced at 30 SWs/min. Conclusions: SWL applied at 60 SWs/min produces significantly less renal injury than SWL at 120 SWs/min, and produces an equivalent level of injury as that seen at 30 SWs/min.

8:15 3aBB2. Shock wave lithotripsy treatment at 60 shock waves per minute is an appropriate protocol to minimize tissue injury. Bret Connors, Andrew Evan, Philip Blomgren, Rajash Handa, Cynthia Johnson, James McAteer 共Dept. of Anatomy, IU School of Medicine, Ms-5055, 635 Barnhill Dr., Indianapolis, IN 46202兲, Lynn Willis 共IU School of Medicine, Indianapolis, IN 46202兲, and James Lingeman 共Int. Kid. Stone Inst., Indianapolis, IN 46202兲 Previous work has shown that the size of the renal hemorrhagic lesion caused by extracorporeal shock wave lithotripsy 共SWL兲 is greatly reduced when shock waves 共SWs兲 are delivered at 30 SWs/min instead of at the more commonly used rate of 120 SWs/min 共0.08⫾0.02% versus 3.93

Invited Papers 8:30 3aBB3. Renal heme oxygenase-1 upregulation after shock wave lithotripsy. Daniel L. Clark, Bret A. Connors, Andy P. Evan, Rajash K. Handa, and Cynthia D. Johnson 共Dept. of Anatomy Cell Biology, Indiana Univ. Sch. of Medicine, 635 Barnhill Dr., Indianapolis, IN 46202, [email protected]兲 Shock wave lithotripsy 共SWL兲 is known to induce oxidative stress and a rapid inflammatory response in renal tissue. The purpose of this study was to determine the location and quantify markers for oxidative stress and inflammation in a porcine model of acute SWL-induced renal injury. The lower pole calyx of left kidneys of female pigs received 2000 shock waves at 24 kV/2 Hz from a Dornier HM3 lithotripter and subsequently monitored for 4 h. Heme oxygenase-1 protein 共HO-1兲 was measured in renal microsomes by Western blot. Renal medulla HO-1/␤-actin ratios were 1.186 ⫾ 0.48 for treated pole 共F2兲, 0.293 ⫾ 0.23 for treated kidney upper pole, and 0.122 ⫾ 0.075 for contralateral kidney 共n⫽6兲. Thus, we observed an eightfold induction of HO-1 in renal medulla at F2 compared to the upper pole medulla of the treated kidney and the contralateral kidney medulla. In contrast, renal cortex at F2 did not show a similar HO-1 induction. The highly localized HO-1 induction in SWL-treated renal medulla parallels our previously reported finding of interleukin-6. These data together suggest that an early inflammatory response and oxidative stress appear primarily in the treated renal medulla within 4 h after SWL. 关Work supported by NIH兴. 2620




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8:45 3aBB4. Low-energy shock wave pretreatment results in greater vasoconstriction and less injury in the kidney compared to high-energy shock wave lithotripsy treatment alone. Rajash K. Handa, Andrew P. Evan, Bret A. Connors 共Dept. of Anatomy and Cell Biology, Indiana Univ. Sch. Med., Indianapolis, IN 46202兲, Lynn R. Willis, Sujuan Gao 共Indiana Univ. Sch. Med., Indianapolis, IN 46202兲, Marla Paun, and Michael R. Bailey 共Univ. of Washington, Seattle, WA 98115兲 Pretreating the kidney with low-energy shock waves 共SWs兲 before administering a clinical dose of high-energy SWs has been found to greatly decrease the hemorrhagic lesion that normally results from high-energy shock wave lithotripsy 共SWL兲 treatment alone. We tested the hypothesis that this novel pretreatment SWL protocol results in a greater and/or earlier renal vasoconstriction than clinical SWL alone, which could potentially explain the reduced bleeding in the kidney. Anesthetized pigs were treated with a clinical dose of SWs 共2000 SWs, 24 kV, 120 SWs/min兲 or the pretreatment protocol 共500 SWs, 12 kV, 120 SWs/min ⫹ 3-min pause ⫹ 2000 SWs, 24 kV, 120 SWs/min兲 using the HM3 lithotripter. Sonography 共color and pulsed ultrasound兲 was used to locate a resistance artery within the SW-treated pole of the kidney and to take resistance index 共RI兲 measurements from the blood vessel to estimate the resistance /impedance to blood flow. The results demonstrated that RI increased 共renal vasoconstriction兲 earlier and greater during the pretreatment protocol compared to normal clinical SWL. Constricted blood vessels would likely be less prone to rupture by SWs and, if broken, would bleed less—resulting in a smaller hemorrhagic lesion.

Contributed Paper partial discharge of the capacitor 共leakage promoted by ⬃0.6 mS conductivity of the surrounding water兲, such that the average energy remaining at the capacitor at the moment of breakdown was reduced four times compared to new electrodes. However, with new electrodes almost 90% of the energy was lost in the circuitry rather than in the spark, as the resistance of the spark 共R⬃0.03 ⍀兲 was much smaller than the resistance of the remainder of the circuit—including the high-voltage switch and connective wires 共r⬃0.23 ⍀兲. With old electrodes, most of the energy was released in the spark, as the electric efficiency R/共R⫹r兲 approached ⬃90%. The product of electric efficiency and capacitor energy agreed closely with both the acoustic energy and the volume of the primary bubble produced at spark discharge. 关Work supported by NIH-DK43881.兴

9:00 3aBB5. Efficiency of spark discharge in electrohydraulic lithotripsy. Yuri A. Pishchalnikov, Mark M. Kaehr, R. Jason VonDerHaar, Irina V. Pishchalnikova, and James A. McAteer 共Dept. of Anatomy and Cell Biology, Indiana Univ. Sch. of Medicine, 635 Barnhill Dr., Indianapolis, IN 46202, [email protected]兲 Electrohydraulic lithotripters and SWT devices generate shock waves by discharge of a high-voltage capacitor through submerged electrodes. As the electrodes age, the interelectrode gap widens. How this affects the efficiency of spark generation was studied using a research HM3-clone lithotripter. Widening of the interelectrode gap 共⬃0.3 mm with new electrodes; ⬃2.5 mm after 4000 discharges兲 increased the lag-time to breakdown 共⬃0 to ⬃30 µs, respectively兲. Increased lag-time as electrodes aged was associated with

Invited Paper 9:15 3aBB6. Bubble dynamics with tissue confinement in shock-wave lithotripsy. Jonathan B. Freund 共Mech. Sci. Eng., Univ. of Illinois at Urbana–Champaign, 1260 W Green St., MC-244, Urbana, IL 61801, [email protected]兲 and Ratnesh Shukla 共Univ. of Illinois at Urbana–Champaign, Urbana, IL 61801兲 Estimates are made of the effect of confinement by tissues on the action of small bubbles when subjected to strong pressure waves. The applications of interest are biomedical procedures involving short strong ultrasound bursts or weak shocks of the kind delivered in shock-wave lithotripsy. Confinement is anticipated to be important in suppressing mechanical injury and slowing the rate of its spread. We consider bubbles in a liquid such as blood within a small vessel in the tissue. A generalization of the Rayleigh–Plesset equation allows us to estimate the effect of the elasticity and viscosity of the surrounding tissue. Ranges of soft-tissue properties are estimated from a variety of different measurements available in literature. Solutions suggest that elasticity is insufficient to significantly alter bubble dynamics, but that viscosities from the mid-to-high range of those suggested might play a significant role in suppressing bubble action. Simulations in two space dimensions of a shocked bubble in a waterlike fluid interacting with a viscous material show that the much more complicated bubble jetting dynamics in this configuration is also significantly suppressed. The dynamics of this suppression is investigated.

Contributed Paper 9:30 3aBB7. Simulation of three–dimensional crack profiles in shock wave lithotripsy. Maddegedara Lalith Lakshman Wijerathne, Hide Sakaguchi 共JAMSTEC, Yokohama Inst. for Earth Sci., 3173-25 Showa-machi, Yokohama 236-0001, Japan.兲, Kenji Oguni, and Muneo Hori 共Univ. of Tokyo, Bunkyo-Ku, Tokyo 113-0032, Japan.兲 Some of the experiments reported by Xufeng Xi and Pei Zhong in 2001 were simulated to explore the sources of crack initiation and propagation in shock wave lithotripsy 共SWL兲. An interesting result they reported was the T-shaped crack pattern in plaster of paris cylinders, subjected to transverse pressure pulses. This nontrivial crack pattern and some others were simulated, in 3-D, using a numerical technique called PDS-FEM. According to

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this 3-D simulations, it was found that the interference of reflected and focused high pressure pulse, by the distal surface, and the lagging low tensile phase created high tensile regions in the cylindrical sample. These high stress regions initiate and drive two horizontal and vertical cracks leading to the T-shaped crack. Due to the lack of data, a typical lithotripter pressure wave profile and material properties for plaster of paris were used. The observed crack patterns were successfully regenerated in 3-D, irrespective of these approximations. The distances between the vertical crack and the distal face for the crack patterns of the experiments and numerical simulations are nearly 0.34⫻d and 0.35⫻d, respectively 共d⫽diameter兲. This quantitative comparison shows the potential applications of PDS-FEM for exploring and further development of SWL technology.



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Invited Papers 9:45 3aBB8. Shock wave interaction with cavitation bubble clusters generated in lithotripsy. Derek C. Thomas, Todd A. Hay, and Mark F. Hamilton 共Appl. Res. Labs., The Univ. of Texas at Austin, Austin, TX 78713-8029兲 Collapse of cavitation bubbles generated in shock wave lithotripsy is essential to the comminution of kidney stones. After passage of the shock, however, if insufficient time has elapsed for the bubbles to dissolve, acoustic scattering from residual bubbles shields the stone from the next shock. Therefore, cavitation also limits the maximum firing rate. As important as collective bubble dynamics are to the efficacy of shock wave lithotripsy, behavior of the bubble clusters is among the least understood physical processes involved. A model was developed previously for the pulsation and translation of dynamically coupled spherical gas bubbles 关Ilinskii et al., J. Acoust. Soc. Am. 121, 786 共2007兲兴. This model was augmented to account for interaction with the focused shock wave incident on the cluster at the order of the Born approximation. Diffraction of the shock wave is described by the KZK equation. The model predicts translation and coalescence of the bubbles due to transmission of the shock through the cluster. Predicted also is the acoustic wave scattered from the cluster, which in the forward direction is the leading order effect of the cluster on the transmitted shock wave. 关Work supported by the ARL McKinney Fellowship in Acoustics and NIH DK070618.兴 10:00—10:15 Break 10:15 3aBB9. Shock wave lithotripsy can alter urinary acid-base pH regulation. Rajash K. Handa, Bret A. Connors, Cynthia D. Johnson, Andrew P. Evan 共Dept. of Anatomy and Cell Biology, Indiana Univ. Sch. Med., Indianapolis, IN 46202兲, Mahesh C. Goel, James E. Lingeman 共Methodist Hospital Inst. for Kidney Stone Disease, Indianapolis, IN 46202兲, Elaine M. Worcester, and Fredric L. Coe 共Univ. of Chicago, Chicago, IL 60637兲 The renal papilla is particularly susceptible to injury by shock waves 共SWs兲. Since the papilla is vital for urinary pH regulation, we hypothesized that shock wave lithotripsy 共SWL兲-induced damage of papillae will alter the pH of the urine. Experiments were conducted in four female adult Gottingen minipigs. The HM3 lithotripter delivered a total of 8000 SWs 共24 kV, 120 SWs/min兲 among all papillae of one kidney, while the untreated, opposite kidney was used as control. The pigs were allowed to recover and 5 weeks later they were anesthetized. Serial urine collections were obtained from the SW-treated and untreated kidney. Urine was collected under mineral oil and immediately tested for its pH. Both kidneys were then perfusion fixed for histological analysis. Urinary pH was 0.17 units greater 共P⬍0.05兲 in the SW-treated kidney compared to the untreated kidney. Histology showed scarring in all regions of the SW-treated kidney, with thick ascending limbs and collecting ducts having grossly abnormal morphologies indicative of cellular proliferation. These results suggest that SWL-induced injury can cause remodeling of nephron structures and long-term impairment in the regulation of urinary pH. 10:30 3aBB10. Ureteroscopic ultrasound technology to size kidney stone fragments: Proof of principal using a miniaturized probe in a porcine model. Mathew D. Sorensen, Anup Shah 共Dept. of Urology, Univ. of Washington Sch. of Medicine, 1959 NE Pacific St., Box 356510, Seattle, WA 98195, [email protected]兲, Michael S. Canney 共Univ. of Washington, Seattle, WA 98105兲, Oleg A. Sapozhnikov 共Moscow State Univ., Moscow 119992, Russia兲, Joel M. H. Teichman 共Univ. of British Columbia, Vancouver, BC V6Z 1Y6, Canada兲, and Michael R. Bailey 共Univ. of Washington, Seattle, WA 98105兲 Background: the ability to measure stone fragment size could help prevent attempting to extract too large a stone fragment. We evaluated the ability of a 1.2 mm 共3.6 French兲 ultrasound probe to measure stone fragments in a porcine kidney. Methods: 15 human stones of three types 共five each calcium oxalate, cystine, calcium phosphate兲 sized 3–7 mm were placed deep in a porcine kidney collecting system. The sound speed of each stone type was determined using a separate reference stone. A 2 MHz, 1.2 mm needle hydrophone was used to send and receive ultrasound pulses. Stone thickness was calculated as d⫽c*t/2 by determining the signal transit time through the stone, t, and the stone sound speed, c. Calculated stone thicknesses were compared to digital caliper measurements. Results: Stone size was determined for all 15 stones. Correlation between ultrasound-determined thickness and caliper measurements was excellent 共r2⫽0.90, p⬍0.0001兲 with ultrasound performing well in all three stone types. All stone measurements were accurate within 1 mm, and ten 共66%兲 stone measurements were accurate within 0.5 mm. Conclusions: Ultrasound-based measurements are accurate and precise using a 3.6 French probe with stone fragments placed deep in a porcine kidney. 关Work supported by Grants NIH DK43881 and NSBRI SMST01601.兴

Contributed Papers 10:45 3aBB11. Ellipsoidal-reflector high intensity focused ultrasound system with integrated safety monitoring. Joshua Samuels and Vesna Zderic 共Dept. of Elec. and Comp. Eng., The George Washington Univ., 801 22nd St. NW, Washington, DC 20052, [email protected]兲 High intensity focused ultrasound 共HIFU兲 transducers can be created using concave piezo elements, acoustic lenses, phased arrays, or ellipsoidal reflectors. By using a 2 MHz cylindrical piezoelectric crystal and a brass ellipsoidal reflector, it was possible to use the base of the transducer to house specific devices which can be integrated into a safety system for the device. This system assists in focal point positioning, ablation confirmation, 2622


as well as assuring proper flow of coolant through the attached water pillow to couple the device. These methods combine to protect the patient and the device itself from improper use or dangerous positioning of the focal point within the tissue. The proposed system utilizes an unfocused 3.5 MHz ultrasound transducer to act as a rangefinder, determining the distance of the tissue from the transducer. A simple graphical user interface allows the maximum allowed depth of ablation to be user defined and a warning displayed if needed. A water pillow with integrated flow meter is used to provide cooling and coupling to the tissue. There is also a housed video camera in the device which could provide visual confirmation of ablation if used laparoscopically or for superficial lesions. 157th Meeting: Acoustical Society of America


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11:00 3aBB12. In vivo simulation of shock wave lithotripsy: Wave focusing in inhomogeneous materials. Jeffrey Krimmel and Tim Colonius 共Caltech 1200 E California Blvd., MC 104-44, Pasadena, CA 91125, jkrimmel @caltech.edu兲

time of flight to each element and array geometry were used to determine the most likely location of the stone. A comparison of threshold crossing and cross-correlation for detecting signal arrival indicated that while the former yielded faster computation time, the latter was more robust to noise. Stone position was determined to within 2 mm for locations within 10 mm of the focus. For distances beyond 10 mm, the optimization routine was not able to reliably predict stone location but could indicate that the stone was not within the focal region. 关Work supported in part by NIH.兴

Shock wave generation and focusing in electrohydraulic, electromagnetic, and piezoelectric lithotripters are simulated numerically. Inhomogeneities associated with wave propagation in vivo are modeled using data from The Visible Human Project. The approximate time-domain relaxation model of Yang and Cleveland 共2005兲 was used to simulate attenuation and dispersion in the tissuelike media. The simulations utilize a MUSCL-type shock capturing scheme with adaptive mesh refinement 共AMR兲. In vitro focal region pressure measurements compare favorably with available experimental data for each lithotripter type. Preliminary in vivo simulation results show significant dispersion associated with the nonuniform sound speed, including increases of up to 50% in focal pressure amplitudes and the presence of multiple pressure minima/maxima in the focal waveform. We will also discuss the extension of the AMR framework to account for cavitation via a previously developed ensemble-averaged continuous two-phase flow model.

11:30 3aBB14. Lung hemorrhage produced by exposure to underwater acoustic impulses. Diane Dalecki, Sally Z. Child, and Carol H. Raeman 共Dept. of Biomedical Eng., and the Rochester Ctr. for Biomedical Ultrasound, 310 Goergen Hall, Univ. of Rochester, Rochester, NY 14627, dalecki @bme.rochester.edu兲 Underwater acoustic impulse sources are used in various commercial and military applications. The objective of this study was to investigate the response of mammalian lung to exposure to underwater acoustic impulses. A laboratory-based acoustic exposure system was developed to investigate the bioeffects of underwater impulses. Underwater acoustic impulses were generated using a ten cubic inch air gun operated in a large water tank. Underwater acoustic impulses with peak pressure amplitudes ranging from 0 共sham兲 to 110 kPa were investigated. Experiments were performed with anesthetized adult mice. Each exposure consisted of five acoustic impulses with approximately 20 s between impulses. Mammalian lung hemorrhage can occur in response to exposure to underwater acoustic impulses. The pressure threshold for lung hemorrhage resulting from five air gun impulses was approximately 50 kPa. The extent of lung damage increased with increasing pressure amplitude. The results of this work are relevant to establishing safety guidelines for swimmers and divers exposed to underwater sound fields.

11:15 3aBB13. Kidney stone tracking in vitro using an acoustic triangulation paradigm. Jonathan M. Kracht and Robin O. Cleveland 共Dept. of Mech. Eng., Boston Univ., 110 Cummington St., Boston, MA 02215兲 During shock wave lithotripsy, stones undergo motion which can place them outside the focal zone of the lithotripter. This results in shock waves being delivered that do not impact the stone but may injure tissue. Tracking stones using diagnostic ultrasound imaging 共⬃4 MHz兲 has proven to be challenging. Here we employed an array of seven relatively low-frequency 共⬃600 kHz兲 elements to detect scattered signals from an artificial kidney stone in the presence of a tissue phantom. Using an optimization routine, the


COUNCIL SUITE, 9:00 TO 11:15 A.M. Session 3aEA

Engineering Acoustics, Structural Acoustics and Vibration, Noise, and Acoustical Oceanography: Acoustical Engineering of Wind Turbines Thomas R. Howarth, Chair Naval Sea Systems Command Division Newport, Newport, RI 02841 Chair’s Introduction—9:00

Invited Papers 9:05 3aEA1. Wind turbines: Why they are noisy and what to do about it. Frits van den Berg 共GGD, P.O. Box 2200, 1000CE Amsterdam, The Netherlands, [email protected]兲 Sound from modern, tall wind turbines is related to sleep disturbance and is, per decibel, more annoying than sound from common sources such as road or air traffic. Surveys among residents indicate that there are several reasons for this: the swishing character of the sound, the intrusiveness at night, and the visibility of the wind turbine共s兲. Residential reaction is also determined by the attitude towards wind turbines in the landscape and by economical benefits. From acoustical research different explanations have arisen as to why the sound is amplitude modulated. For a distant observer it is the result of the change in trailing sound level due to the change in wind that the revolving blades encounter. High night-time sound levels are due to an increase in rotor height wind speed simultaneously with a decrease in near-ground wind speed. Wind turbine design has been directed to higher yields per turbine. Less attention has been given to low noise blades and rotor speed reduction. Low noise design could also include a reduction in the modulation amplitude and more sophisticated speed reduction; viz., at high annoyance conditions. Also, involving residents in wind farm planning may have a high potential to reduce annoyance. 2623




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9:30 3aEA2. An overview of the acoustical activities at the National Wind Technology Center. Arlinda Huskey 共NREL, NWTC, 1617 Cole Blvd., MS 3911, Golden, CO 80401, Arlindaគ[email protected]兲, Moriarty Patrick, Jeroen van Dam 共NREL, NWTC, Golden, CO 80401兲, Eric Simley, and Scott Palo 共Univ. of Colorado兲 The National Wind Technology Center 共NWTC兲 has been involved in wind turbine acoustics since the 1980s. The areas of work include standards development, measurement and analysis, prediction code development, and acoustic arrays. Most measurements are conducted to the IEC 61400-11, a standard specifically for acoustic measurements of wind turbines. The NWTC is involved in the development of this standard. The standard results in reports of overall levels as well as tonality. The NWTC has also developed a semiempirical acoustic noise prediction code for wind turbines. Validation of this code with test data 共both wind tunnel and field measurements兲 shows reasonable prediction accuracy for both airfoil self noise and turbulent inflow noise. Lastly, to assist with wind turbine noise reduction and to identify the loudest components an acoustic array was developed to better locate noise on wind turbines. This paper will describe the NWTC’s past and current activities in wind turbine acoustics including test methods and results. 9:55 3aEA3. Ocean acoustic noise budgets: Application to the environmental assessment of offshore wind power generation. James H. Miller, Gopu R. Potty, Andres Nunez Perez 共Dept. of Ocean Eng., Univ. of Rhode Island, Narragansett, RI 02882, [email protected]兲, Kathleen Vigness Raposa 共Marine Acoust., Inc., Middletown, RI 02842兲, and Jeffrey A. Nystuen 共Univ. of Washington, Seattle, WA 98105-6698兲 A noise budget is a listing of the various sources of acoustic noise and their associated ranking by importance. A number of different types of budgets can be conceived using various acoustic measures such as intensity, energy, or duration of maximum amplitude level. These budgets are typically parameterized by frequency and are usually computed over 1/3 octave bands. As part of the environmental assessment of the proposed offshore wind power generation project under the Rhode Island Special Area Management Plan 共SAMP兲, noise measurements were made using the Passive Acoustic Listener 共PAL兲 systems off the coast of Rhode Island prior to the installation of any wind power facilities. Two PALs were deployed within two miles of Block Island in water depths of 20 m from October 6 to November 11, 2008. The data included noise spectra and source identification every 3 min. Short snapshots of unusual sounds were also recorded. From this data, the ocean acoustic noise budget is computed with contributions from shipping, wind/waves, marine mammals, and rain from 500 Hz to 50 kHz. The ship noise data is correlated with ship traffic data from the Automatic Identification System 共AIS兲. 关Funding provided by the Rhode Island Office of Energy Resources.兴 10:20 3aEA4. Prediction methodologies for tonal and broadband noise from horizontal-axis wind turbines. Brent Paul, Rudolph Martinez, Donald Thompson, and James Uhlman 共CAA-Alion Corp., 84 Sherman St., Cambridge, MA 02140 [email protected]兲 This paper describes a set of computational-analytic predictive tools for the following mechanisms of aerodynamic sound and vibration for a wind turbine’s blades in ducted or open arrangements: 共a兲 Infrasound and tonal low-frequency nearfield noise from the interaction of blades with a nonuniform meanflow that is steady in its own reference frame; 共b兲 mid-frequency broadband noise from the “haystacked” chopping of an incident turbulent freestream; 共c兲 high-frequency noise from self-generated turbulence near the trailing edge of each blade’s suction side. Contributors to tonal mechanism 共a兲 include the rotor’s static loads as required by power generation 共nearfield “Gutin” component of infrasound兲, and operation in a local wind shear or in the mean wake of the turbine’s tower when set up as a downstream machine. These predictive tools include models of the spatially nonuniform mean and turbulent flows that typically strike a wind turbine’s blades, as well as preprocessors of that information when made available by either field measurements or off-line calculations. The codes’ physical content includes the possibility of uneven spacing for the turbine’s blades and for their interaction with statistically inhomogeneous turbulence for mechanism 共b兲. Sample predictions compare the codes’ estimates of sound production to measurements from the open literature.

Contributed Papers 10:45 3aEA5. Methodologies to address limitations of the ISO9613-2 standard for wind turbine noise propagation modeling. Erik J. Kalapinski 共Tetra Tech EC Inc., 133 Federal St., Boston, MA 02110, erik.kalapinski@tteci .com兲 The accuracy of the noise propagation modeling results is dependent on: 共1兲 the sound source data entered into the model as reported by wind turbine equipment manufacturers as specified under per IEC 64100-11 standard; 共2兲 site specific topographical, meteorological, and terrain conditions; and 共3兲 the propagation algorithms of the acoustic modeling standard that are applied. For wind energy facilities sited in the US, the ISO 9613-2 standard is most commonly used due to its proven effectiveness to accurately predict the sound levels at a distance for industrial and commercial projects in an outdoor environment. The propagation algorithms employed by the ISO 9613-2 standard account for geometrical divergence, atmospheric absorption, ground attenuation, screening effects, and favorable sound propagation conditions that would occur during omnidirectional downwind meteorological conditions. The purpose of this paper is to identify limitations inherent in the ISO 9613-2 standard to the specialized application of wind turbine acoustics and nonstandard atmospheric conditions. Methodologies are pre2624


sented to more accurately describe atmospheric and lateral attenuation effects, which can result in significant uncertainties in the noise levels calculated both in proximity and at distant receptor locations.

11:00 3aEA6. Vibration analysis of turbine low-pressure bladed-disk in 500-MW fossil power plant. Dooyoung Lee, Youngchae Bae, Heesoo Kim, Yookryun Lee, Hongil Choi, and Hyun Lee 共Hydro & Fossil Power Generation Lab., KEPRI, 103-16 Munji Yusung Daejon, Korea, 305-380, dylee @kepri.re.kr兲 Many failures of turbine blades are caused by the coupling of aerodynamic forcing with bladed-disk vibration characteristics. Vibration analysis for an individual turbine blade does not include all the coupled characteristics of whole bladed-disk system. This paper shows the coupled vibration characteristics of a low-pressure 共LP兲 turbine bladed-disk in a 500-MW fossil power plant for the purpose of confirming equipment integrity. In order to verify the finite element model, analytic and experimental modal analyses for a single blade were performed and reviewed with boundary conditions not only where both ends were free to move but also where its root was 157th Meeting: Acoustical Society of America


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fixed. Natural frequencies and corresponding mode shapes were calculated for the bladed-disk first, and then proximity of modes to sources of excitation was assessed by means of interference diagrams to examine resonance. The result of analysis was ascertained by being compared with a field test for the bladed-disk without centrifugal and aerodynamic forces. In addition,

dynamic stress as well as steady stress which results from centrifugal and steady-state steam forces was also calculated at dangerous modes of operation. It is expected that these dynamic characteristics will be used effectively to identify the root causes of blade failures and to perform prompt maintenance.


STUDIO SUITE, 8:25 TO 11:45 A.M. Session 3aED

Education in Acoustics and ASA Student Council: Project Listen Up James M. Sabatier, Chair National Ctr. for Physical Acoustics, Univ. of Mississippi, University, MS 38677 Chair’s Introduction—8:25

Invited Papers

8:30 3aED1. A simple experiment for understanding resonant air columns. Theodore F. Argo, IV, Chad A. Greene, and Preston S. Wilson 共Mech. Eng. Dept. and Appl. Res. Labs., The Univ. of Texas at Austin, Austin, TX 78712-0292, [email protected]兲 One goal of Project Listen Up is to enhance children’s understanding of acoustics through engagement in basic acoustics experiments. This work proposes an experiment that examines the resonant frequencies of an air column. Equipment for this experiment consists of a small tunable oscillator circuit connected to a loudspeaker, which can also be used for other experiments in the kit. The experimenter will provide a cardboard tube, rubber band, plastic wrap, and sand. Resonance is demonstrated by placing the loudspeaker at the base of the tube, covering the top of the tube with a plastic wrap membrane, and placing sand grains on top of the membrane. As frequency is adjusted, the sand grains are excited at the resonance frequencies of the tube. Frequencies at which sand motion is observed can be compared to a simple algebraic model, which relates the length of the tube to the resonance frequencies of the system. An optional advanced experimental track investigates the effect of varying the length of the tube. This experiment develops intuition for the relationship between frequency and wavelength and builds understanding of resonant systems.

8:45 3aED2. Sound speed measurements in air using a variable sound source and tubes. Stanley A. Cheyne and Walter C. McDermott 共Dept. of Phys. and Astronomy, Hampden-Sydney Coll., Hampden-Sydney, VA 23943兲 Sound speed measurement using standing waves and tubes is a standard experiment in every introductory physics laboratory. It is an experiment that is relatively simple to understand both conceptually and mathematically. The idea behind this work is to reproduce the same experiment, at low cost, making it suitable for project listen up. Two approaches were made. The first was to design and construct a small, low cost, variable sound source that could be used to determine the resonances of several fixed length tubes. The device is simple in design and easy to use. As the frequency is varied, the resonances can be determined by listening with the ear. Once done, the sound speed can be easily calculated. The second method was to use a free, online, function generator as the sound source and repeat the experiment as previously discussed. Results of both methods will be given and demonstrated along with pros and cons of each.

9:00 3aED3. Why we have two ears—a hands-on experiment comparing monaural and binaural hearing. Ralph T. Muehleisen 共Civil, Environ., and Architectural Eng., Illinois Inst. of Technol., 3201 S. Dearborn St., Rm. 228, Chicago, IL 60616兲 Whether they fly, swim, crawl, or walk, vertebrates have binaural auditory systems. Two ears provide redundancy in case of injury to the auditory system, improve the ability to detect quiet sounds and, perhaps most importantly, improve the ability to localize sound. This paper describes a simple experiment in which two individuals work together to investigate the sound localizing abilities of a human using monaural and binaural hearing. In the experiment, one person sits blindfolded in the center of a circle and acts as a listener. The other person moves a sound source around a circle, equidistant from the listener while the listener attempts to locate the direction of the source. The experiment is repeated for both monaural 共with an earplug in one ear兲 and binaural 共using both ears兲 hearing and for impulsive and low frequency tonal sources. The experiment is best attempted in an environment with very few nearby reflecting sources such as the outdoors or a very large room. 2625




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9:15 3aED4. Two-dimensional normal modes: Experiment and finite element analysis. Uwe J. Hansen 共Dept. of Chem. & Phys., Indiana State Univ., Terre Haute, IN 47809兲 Bending wave propagation on a two-dimensional plate is reduced to standing waves with the imposition of boundary conditions. These standing wave patterns can be observed with sand, which accumulates near the nodal lines. These sand patterns are usually called Chladni patterns after Chladni, who first observed and described them. Using a simple lapel microphone, these mode patterns can also be illustrated by noting the phase shift when observing the near-field sound pattern very close to the vibrating plate. Both Chladni patterns and phase mapping of patterns will be illustrated. A relatively inexpensive software package enables finite element calculations of vibrating plates. Normal mode vibration can easily be illustrated in animation on a computer screen. Both the calculation process and the animation will be illustrated. 9:30 3aED5. Acoustics outreach and scouting: A merit badge proposal. Kent L. Gee, Brian E. Anderson, Tracianne B. Neilsen, and Scott D. Sommerfeldt 共Dept. of Phys. and Astron., Brigham Young Univ., N283 Eyring Sci. Ctr., Provo, UT 84602, [email protected]兲 The success of the Girl Scouts of America 共GSA兲 and the Optical Society of America’s “Project Lighten Up” and the proposed “Project Listen Up” have prompted a discussion of how Scouting can be used as an outreach vehicle to interest today’s youth in science and, more particularly, in acoustics. One possibility for this would be the drafting of a “Sound and Audio” merit badge for the Boy Scouts of America 共BSA兲 or a similar activity award for the GSA. The BSA currently offers 121 merit badges for scouts, including varied topics such as archeology, rifle shooting, plumbing, truck transportation, and coin collecting. Although there are physical sciencerelated merit badges 共e.g., composite materials, chemistry, nuclear science兲, there is not a badge that deals directly with acoustics. This talk will outline how an acoustics-related merit badge may help engage youth interest in science and discuss ideas for possible badge requirements. 9:45 3aED6. Wave interaction effects for all ages. Scott D. Sommerfeldt 共Dept. of Phys., Brigham Young Univ., N181 ESC, Provo, UT 84602, [email protected]兲 Wave interaction effects occur in many everyday situations. A number of important principles associated with these interactions can be readily demonstrated without the need for extensive and expensive equipment. Using two low-cost speakers, it is possible to easily demonstrate the basic principle underlying active noise control by placing the speakers close together and first wiring the speakers “in-phase” to achieve constructive wave interference and then wiring the speakers “out-of-phase” to achieve destructive wave interference. This setup results in a global attenuation of the sound field, making the audible effect easily discernible. The dependence of the interaction on frequency and spacing 共kd兲 can be demonstrated by changing the frequency of the excitation signal. In addition, by separating the speakers the interaction of two waves to create a standing wave can be demonstrated, and the nodes/antinodes established can be audibly heard as the listener moves his/her ear through the field. Finally, these concepts can be used to understand why loudspeakers are mounted in enclosures. As the loudspeaker is placed in an enclosure the direct interaction of 共out-of-phase兲 waves from the front and back of the loudspeaker cone is inhibited, thus resulting in increased radiation efficiency.

Contributed Papers 10:00 3aED7. A simple analytical demonstration of transient and steady-state response in a dissipative closed waveguide based on the d’Alembert solution. Jerry H. Ginsberg 共G. W. Woodruff School of Mech. Eng., Georgia Inst. of Technol., Atlanta, GA 30332-0405, [email protected]兲

10:30 3aED8. Hands on and homemade coupled oscillators for Project Listen Up. Sean M. Mock and Murray S. Korman 共Dept. of Phys., U.S. Naval Acad., Annapolis, MD 21402, [email protected]兲

Previously 关J. H. Ginsberg, J. Acoust. Soc. Am. 119, 1954–1960 共2006兲兴, the d’Alembert solution of the wave equation was adapted to address the response to initial conditions of a one-dimensional waveguide whose terminations have an arbitrary real 共possibly dissipative兲 impedance. The technique creates virtual images on the other 共i.e., nonphysical兲 side of each wall to convert the closed waveguide to one of infinite extent. The present work extends the development to cases where an arbitrary velocity is applied to one wall. The imaging technique allows one to visually track the evolution of the spatial pressure profile and the relation of temporal waveforms at various locations. The relatively low level of mathematical skills entailed in the formulation makes the method accessible to students at all levels. Application of the technique to periodic excitation of the boundary leads to visual representation of various effects, including reverberation time and various resonance effects, such as uncontrolled growth in the absence of dissipation and approach to steady-state when dissipation is present. Sound files generated from the synthesized connect the physical and audible phenomena.

A coupled pendulum oscillator experiment recently developed within the U.S. Naval Academy Physics Department seems a possible candidate for the Project Listen Up initiative. A plexiglass frame supported by four legs suspends two 500 g masses 30 cm below by two chains of paper clips each, meeting in the shape of a V on either bob. A light spring 共k⫽3.64 N/m兲 connects the two, completing the coupled oscillator system. Displacement of the oscillators was measured using Pasco motion sensors, a Vernier LabPro unit, and a laptop. LOGGERPRO and MATHEMATICA software helped compare theory with experiment. However, one does not need these resources to experiment with coupled oscillators—it can be improvised using ordinary household materials for young students! An inexpensive wooden picture frame with islet screws supports pendulums using two Dixie cups filled with sand or coins as masses. The possibilities for learning seem endless! A simple stopwatch, meter stick, fulcrum, and measuring cups are incorporated in experimental and theoretical comparisons, including the periods of normal modes. Students can explore density through balancing masses with volumes of water. Demonstrating beat frequencies from mistuned xylophone bars or guitar strings conveys a subtlety of the experiment without overpowering the young minds of future scientists.

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10:15—10:30 Break



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10:45 3aED9. Helmholtz resonator experiment for Project Listen Up. Marianne C. Sparklin and Murray S. Korman 共Dept. of Phys., U.S. Naval Acad., Annapolis, MD 21402, [email protected]兲 The behavior of sound waves and resonant effects can be observed using Helmholtz resonators. Resonators are built from identical round wooden boxes purchased from a craft store. The tops are glued and drilled with hole diameters from 2–3 cm. We can study the resonant behavior as a function of hole diameter only. The end effect is large compared with the thickness of the orifice 共0.6 cm兲. In the experiment, a swept tone 共100–900 Hz兲 from a small speaker drove the resonator. One studied the output of the microphone located near the orifice. One could use a swept spectrum analyzer, a function generator, or tuning fork with varying weights to measure the resonant frequency of the box. A plot of hole diameter versus frequency can be compared with the theoretical Helmholtz resonant frequency prediction, which depends on the volume of the box, the cross sectional area, the sound speed of air, and the effective length of the hole. One can model the effective length of the resonator as the thickness of the top plus a constant times the diameter of the hole and get good agreement with the established end correction found in textbooks.

methods and by the acoustic energy flux vector field. The geometrical ray results and the energy flux vector field resulting from the wave solution are compared with experiment.

11:15 3aED11. The effect of the teaching-learning sequences connecting sound wave at microlevel and macrolevel on the student’s understandings for sound transmission. Hyungjun Kim 共Phys. Education Dept., Seoul Natl. Univ, Daehak-dong, Gwanak-gu, Seoul 151-742, [email protected]兲 and Junehee Yoo Previous studies reported that students had some difficulties in understanding sound waves as longitudinal waves. In this research, most of teaching-learning sequences described sound waves at macrolevel, which were supposed as one source of these difficulties. So teaching-learning sequences connecting sound wave at microlevel and macrolevel were developed and effects were investigated. These teaching-learning sequences were focused on bridging between the movement of particles in air and movements of slinky springs and simulation using the EXCEL program. In addition to that, explaining wave phenomena at macrolevel by the movement of particles at microlevel was emphasized. Predict-observe-explain strategy was used. Evaluated worksheets and video-records were analyzed to figure out conceptual changes.

11:00 3aED10. The energy flow for a spherical acoustic lens: Ray and wave methods vs experiment. Cleon E. Dean 共Phys. Dept., P.O.B. 8031, Georgia Southern Univ., Statesboro, GA 30460-8031, [email protected]兲 and James P. Braselton 共Georgia Southern Univ., Statesboro, GA 304608093兲

11:30 3aED12. Modal analysis for undergraduate laboratories and projects. Andrzej Kotlicki and Chris Waltham 共Dept. of Phys. and Astronomy, Univ. of British Columbia, 6224 Agricultural Rd., Vancouver, BC V6T 1Z1, Canada兲

A simple classroom demonstration consists of a weather balloon filled with carbon dioxide, a sound source, and a microphone. Since the speed of sound is slower in carbon dioxide than in air at room temperature and pressure, the balloon acts as a positive spherical acoustic lens. The accuracy of ray methods in locating the acoustic focus versus a full-blown wave solution approach has been presented previously 关Cleon E. Dean and James P. Braselton, “The energy flow for a spherical acoustic lens: ray vs. wave methods,” J. Acoust. Soc. Am. 123, 3520 共2008兲.兴 Theoretically, this problem presents particular difficulties if the sound source lies in the near field region. The sound emitter is treated as a dipole source equivalent to a rigid oscillating sphere of small size and amplitude of motion relative to the scatterer. The energy flux around the balloon has been visualized by both ray

Vibrational analysis of structures 共musical instruments for example兲 requires a means of excitation, motion detection and a data acquisition system. None of these needs to be very expensive. We have constructed an impact hammer using a piezoelectric crystal from an old barbeque lighter; this provides rapid excitation at all frequencies up to 1 or 2 kHz. Motion detection is now possible using extremely light 共less than 1 g兲 microelectromechnical systems 共MEMS兲 accelerometers that cost only a few dollars each. Twochannel data acquisition at 44.1kHz per channel is available to anyone with a computer equipped with a soundcard. More flexible external systems are also available in the $200 range. Thus, modal analysis is easily within the budgets of undergraduate laboratories. In this presentation we will emphasize the calibration of the impact hammer and evaluation of the MEMS accelerometers.

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EXECUTIVE SALON II/III, 8:00 TO 11:50 A.M. Session 3aNS Noise: Noise Litigation

John Erdreich, Chair Ostergaard Acoustical Assoc., 200 Executive Dr., West Orange, NJ 07052 Chair’s Introduction—8:00

Invited Papers 8:05 3aNS1. Hearing loss litigation. Robert A. Dobie 共Dept. of Otolaryngol., UC-Davis, Sacramento CA 95817兲 Most hearing loss in American adults is attributable to aging, noise, or a combination of these two. While most claims for noiseinduced hearing loss are handled administratively in workers compensation, litigation against employers, premises owners, and manufacturers of noisy equipment continues to pose interesting challenges. Issues of negligence often involve professionals with expertise in noise control, hearing conservation program management, product labeling, and human factors. There are usually two primary issues for clinician experts: How severe is the hearing loss, and what caused it? Audiologists and otologists can draw upon a mass of research to support reasonable opinions in cases with complete data sets. Unfortunately, important data from the past 共e.g., changes in noise exposure and hearing loss over a career兲 are often impossible to obtain. Forensic consulting is terra incognita for most clinicians, requiring analyses and judgments that are rarely called for in clinical practice.

8:35 3aNS2. Minneapolis et al versus the Metropolitan Airports Commission. Paul Schomer 共Schomer and Assoc., Inc., 2117 Robert Dr., Champaign, IL 61821, [email protected]兲 The city of Minneapolis has a law protecting the quietude in various land use areas, including residential areas. In this legal action, plaintiff asserted that the Metropolitan Airports Commission was adversely and significantly affecting the quietude of the residents in the 60–65 DNL zone and that a 5-dB noise insulation package in homes in that zone would ameliorate the situation. There were four tasks for plaintiff’s expert witnesses; 共1兲 Define quietude; 共2兲 Show that without the airport quietude existed in the 60–65 DNL zone; 共3兲 Quantify the impacts including annoyance, speech interference, and sleep disturbance; and 共4兲 Quantify the benefits of a 5-dB noise insulation package. The results were a negotiated settlement for $128 million.

9:05 3aNS3. Qualification of an aircraft ground run-up enclosure using a novel sound monitoring and analysis approach. Kerrie G. Standlee 共Daly-Standlee & Assoc., Inc., 4900 SW Griffith Dr., Ste. 216, Beaverton, OR 97005兲 This paper describes a sound monitoring and analysis program developed to determine if a ground run-up enclosure 共GRE兲 installed at the Portland International Airport was effective in reducing aircraft engine run-up noise radiated to residential neighborhoods during nighttime hours. A noise monitoring and analysis program was developed to fulfill conditions of approval imposed by the Oregon Department of Environmental Quality 共DEQ兲 prior to the construction of the facility. A novel approach was developed whereby unattended sound level meters were used to collect one-second Leq and hourly statistical noise level data near the GRE and at community locations of interest. This data, combined with GRE usage data and weather data, was then subjected to a multistep analysis procedure. The process was found to be very effective at determining when ground run-up events caused community noise levels exceeding DEQ limits. By the end of the project, the procedure was being used to assess 99 percent of the run-ups occurring within the GRE. The sound monitoring and analysis procedure became a very reliable tool in demonstrating that the GRE complied with its conditions of approval.

9:35 3aNS4. Noise issues affecting litigation in condominiums. Jerry G. Lilly 共JGL Acoust., Inc., 5266 NW Village Park Dr. Issaquah, WA 98027兲 Serving as an expert witness in legal actions involving residential condominiums is often a harrowing and extremely challenging task, regardless of which side you represent. If you are representing the HOA, you have to educate your client so that they understand that the mere ability to hear your neighbor is not necessarily unusual and may not be grounds for a defect. If you are representing the architect, developer, or contractor, you have to educate them as to the code requirements as well as the various acoustical performance guidelines that will undoubtedly be introduced by the HOA. In either event, if you do not do your homework you are leaving yourself exposed to be grilled by opposing counsel 共in deposition or at trial兲 without mercy. This presentation will discuss the author’s experience in dealing with these issues, with specific emphasis on problems with the testing standards and performance guidelines that exacerbate the problem. 2628




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10:05—10:20 Break 10:20 3aNS5. Warning audibility in industrial accidents. John Erdreich 共Ostergaard Acoust. Assoc., 200 Executive Dr., W. Orange, NJ 07052兲 Industrial accidents related to warning audibility may be adjudicated in the worker compensation environment or in state courts. One factor that may determine whether the incident becomes a compensation case or a tort is if the employer could reasonably expect the situation to require an audible warning. The second factor to evaluate is the adequacy of the warning itself. Thus, it is the responsibility of the acoustician to educate the trier of fact about not only the science of audition, but also the state of the art in that represents a consensus of methods to provide such warnings. An example of such a case will be presented.

Contributed Papers 10:50 3aNS6. Can race car sound break windows? David Braslau 共David Braslau Assoc., Inc., 1313 5th St. SE, Ste. 322, Minneapolis, MN 55414兲 Sound from a special class of race cars was cited as cause for sudden breakage of a large pane of tempered glass in a private box that fell and injured a spectator below. Analysis of previously recorded race track noise from a similar track in Minnesota showed that sound levels could exceed the Hubbard rattle criteria but no conclusions could be drawn regarding breakage. Because of time constraints, sound level measurements from a race in Ohio of this vehicle class were taken by Campanella Associates for reference. Those measurements were compared with previously measured levels of other vehicle classes and found to be higher at some frequencies. Since a recorded demonstration performed by the plaintiff showed breakage of a similar pane of glass with an induced flaw and continuously applied sound at 70 to 80 Hz, a field test on a similar window with simulated sound levels based upon measurements from the special vehicle class race was performed with assistance from Synergistic Design Associates. A simulated sound level as high as 117 dBA was generated at the window without breakage. Some conclusions on potential glass breakage from incident sound will be presented. 关Work supported by Johnson & Lindberg, P.A.兴

11:05 3aNS7. Deficiency of the Massachusetts Pure Tone Noise Regulation. Michael Bahtiarian 共Noise Control Eng. Inc., 799 Middlesex Trnpk., Billerica, MA 01821, [email protected]兲 The Commonwealth of Massachusetts Department of Environmental Protection 共MADEP兲 noise regulation has two parts. The first part involves overall A-weighted noise and requires that no source of sound be greater than 10 dB above the background noise. A second part states that no pure tones are allowed. A pure tone condition is defined by the MADEP as any octave band that is greater than the adjacent bands by 3 dB. The author was involved in community noise investigation that showed the deficiency of the pure tone requirement. A suburban community complained of bothersome noise from an industrial abutter. Noise measurements were taken by other consultants which did not register as a pure tone. The author was hired by the community group to conduct measurements on their behalf. Similar octave band measurements were taken with similar results. However, measurements with finer one-third octave band showed significant tonal activity. When compared to commercial standards for pure tones the tonal criterion was met. Further examination of narrowband data showed why the original octave band measurements were not registering pure tone conditions. The author will present his suggestion for changes to the MADEP regulation and welcomes input from others dealing with similar tonal requirements.

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11:20 3aNS8. Uncertainty in field and laboratory acoustical testing: A challenge for the acoustical industry. John LoVerde and Wayland Dong 共Veneklasen Assoc., 1711 16th St, Santa Monica, CA 90404, jloverde @veneklasen.com兲 The statistical uncertainty in acoustical testing has been insufficiently studied in the acoustical community. There are a limited number of studies quantifying measurement uncertainties, especially in the field, but even where uncertainties have been documented, they are largely ignored in practice. As was documented in a previous case 关LoVerde and Dong, J. Acoust. Soc. Am. 124, 2441 共2008兲兴, it is common practice to assume that the test results have low uncertainties 共even if published uncertainties are large兲 and that variations in the results are due to variations in materials, errors in construction, etc. This can be particularly important in noise litigation, where acoustical ratings that are lower than expected are often automatically assumed to be due to construction defect, even though they may be within the expected range. Even without errors in construction, the uncertainties in the acoustical test procedure may be such that some assemblies will meet the relevant statutory requirements and other, nominally identical assemblies will fail. Recent experience and insight will be presented regarding the definition of a construction defect in acoustical assemblies, the overlap of responsibilities between contractors and designers, and the interpretation of building code requirements. 11:35 3aNS9. Designing petrochemical plants to permit retrofitting of any additional controls needed to meet community noise limits. Frank H. Brittain 共Bechtel Corp., 2255 Peavine Valley Rd., Reno, NV 89523兲 Designing petrochemical, power, or industrial plants to meet community noise limits can be expensive. To meet stringent limits, incremental costs often exceed one million dollars per decibel. There is considerable uncertainty, including: overly conservative or unrepresentative vendor noise data, limitations of ray-tracing software, questionable accuracy beyond 1000 m, lack of TL and absorption data below 125 Hz, unreliable IL data for pipe lagging at all frequencies, unexpected operating conditions, and vendors not meeting their equipment noise limits. Atmospheric effects can cause variations of A-weighted community noise levels of 25 dB at 100 m from a refinery, which can make meeting a not-to-exceed noise limit difficult and risky. Further, lack of experience with noise control of any participant 共noise control engineer, project, owner, regulators, or vendors兲 can substantially increase uncertainty. Including sufficient noise controls to cover these uncertainties will be expensive, often overly conservative, and often unnecessarily expensive. One way to substantially lower costs and risks is designing the plant to permit delaying some but not all controls until start-up—if needed. This paper describes the planning needed to permit a partial reliance on retrofit controls, what type of controls can be delayed until start-up, and space allocation. Examples are included.



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BROADWAY III/IV, 8:30 TO 11:15 A.M. Session 3aPA

Physical Acoustics: Infrasound and Outdoor Sound Propagation D. Keith Wilson, Chair U.S. Army Cold Regions Research Lab., Engineering Research and Development Ctr., Hanover, NH 03755-1290 Contributed Papers 8:30 3aPA1. On tropospheric ducting in infrasound. Roger Waxler and Philip Blom 共NCPA, Univ. of Mississippi, University, MS 38677, rwax@olemiss .edu兲 Infrasound can propagate to ranges of many hundreds of km. Signals received on the ground at ranges of 200 km or more have propagated high into the atmosphere through the stratosphere and thermosphere. At shorter ranges, the propagation is dominated by structure in the lower atmosphere such as the jet stream and the atmospheric boundary layer. Theoretical results on the influence of the lower atmosphere on infrasound propagation will be presented.

8:45 3aPA2. On the fast arrivals seen in impulse propagation in the nocturnal boundary layer. Philip Blom and Roger Waxler 共Natl. Ctr. for Physical Acoust., Univ. of Mississippi, University, MS 38677兲 On clear dry nights over flat land, an acoustic duct forms in the atmospheric boundary layer. The duct is formed by a temperature inversion in the lowest few hundred m of the atmosphere and by the stiff wind, known as the nocturnal jet, which commonly develops above the temperature inversion. An impulsive signal undergoes strong dispersion as it propagates in the nocturnal duct and is received at long ranges from the source as an extended wave train consisting of a series of distinct arrivals followed finally by a low frequency tail. The first arrival is of interest here. Through its interaction with the nocturnal jet, the first arrival is often anomalously fast. Accompanying the increased propagation speed is a marked decrease in amplitude. It will be shown that an explanation for this behavior is given by geometrical acoustics.

9:00 3aPA3. Impulsive sound propagation in coastal regions. Xiao Di, Carrick Talmadge, Roger Waxler, Kenneth E. Gilbert 共Natl. Ctr. for Phys. Acoust., Univ. of Mississippi, University, MS 38677兲, and David A. Conner 共U.S. Army Aviation and Missile Command兲 Influenced by the coastal temperature profile and wind profile, the resulting sound speed profiles in coastal regions have certain unique features, such as double inversion zones. As a result, long range sound propagation presents certain properties due to these features. An impulsive sound propagation experiment had been conducted in the morning hours of the summer of 2007 in the coastal Florida area. The test field was 7 km long. Three propane cannons were used during the experiment, located at each end of the test field and in the middle of the test field. Both upwind and downwind propagation data were collected and will be presented. The data showed that coastal region meteorology has a dominant effect on long range sound propagation. Simulated sound propagation results using measured meteorological data are compared with measured impulsive sound propagation data.

9:15 3aPA4. Investigation of dominant sources of pressure fluctuations and infrasonic wind noise in microphones. John Paul Abbott, Richard Raspet, Jeremy Webster, and Jiao Yu 共Natl. Ctr. for Physical Acoust., Dept. of Phys. and Astronomy, Univ. of Mississippi, University, MS 38677兲 2630


Investigation of the time dependent relationship between the vertical wind velocity fluctuations and the pressure sensed on the ground as measured in an open field is done to determine if the turbulence-shear term of the Poisson equation is the dominant source of pressure fluctuations and infrasonic wind noise present in microphones, or some other source. The wind velocity was measured using a three-axis ultrasonic anemometer and six one-dimensional ultrasonic anemometers. The pressure was measured simultaneously using two half-inch free-field pressure microphones, one placed flush with the ground, the other at a height of 1 m above the first. The anemometers were also situated above and adjacent to the microphones. The three axis anemometer was set at a height of 1 m, and the six, onedimensional anemometers, as a vertical array from a height of 0.1–2 m above the ground. As this is still an ongoing investigation, only a description of the experiment and the current findings are presented and discussed.

9:30 3aPA5. New models for wind noise measured in a flat surface under turbulent flow. Jiao Yu, Richard Raspet, Jeremy Webster, and JohnPaul Abbott 共Natl. Ctr. for Physical Acoust. and Dept. of Phys. and Astron., Univ. of Mississippi, University, MS 38677, [email protected]兲 We have previously developed models for predicting the power spectral density of the wind noise pressure measured in a flat plate outdoors from the measured power spectral density of the turbulence and the measured wind velocity profile above the plate 关Yu et al., Proceedings of NCAD 2008, NoiseCon2008-ASME NCAD兴. Recently we have corrected an error in the model for the logarithmic profile wind velocity gradient results and have developed an improved integration method. Also, we have developed a prediction for arbitrary wind velocity profiles using the previous single exponential model. Typical results comparing our predictions with our measurements are presented and analyzed. A simple algebraic fit to the prediction for the logarithmic profile fit form is also provided for use by others. 关Research supported by the U.S. Army TACOM-ARDEC at Picatinny Arsenal, NJ.兴

9:45 3aPA6. Calculations of wind noise underneath a foam covering at the ground surface. Jiao Yu, Richard Raspet, Jeremy Webster, and JohnPaul Abbott 共Natl. Ctr. for Physical Acoust. and Dept. of Phys. and Astron., Univ. of Mississippi, University, MS 38677, [email protected]兲 A foam windscreen reduces the wind noise generated at a microphone. Similarly, a thin foam covering above a surface mounted microphone also lowers the wind noise level effectively. Recent research has focused on developing a physical model for calculating the wind noise pressure fluctuation spectrum measured by a foam covered microphone under a turbulent flow based on our current model for flush mounted bare microphones. The foam surface not only reduces the wind noise at the microphone, but also prevents direct exposure of the microphone to the flow, which reduces the measurement’s sensitivity to details of the meteorological conditions. In this talk, the calculation model will be introduced, and the comparisons between our predictions with the model and our measurements down to low wave number will be presented and discussed. 关Research supported by the U.S. Army TACOM-ARDEC at Picatinny Arsenal, NJ.兴 157th Meeting: Acoustical Society of America


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10:00—10:15 Break 10:15 3aPA7. Study of the impact of input uncertainties on acoustic propagation. Bruce Ikelheimer, Micah Downing, and Michael James 共Blue Ridge Res. and Consultants, 13 1/2 W. Walnut St., Asheville, NC 28801兲 A modular system of acoustical tools has been developed that integrates the physical factors controlling the propagation of acoustical signals. First and foremost, this system provides a prediction of the noise from a source to a receiver location. This ray-tracing prediction takes into account the local terrain, changes in ground impedance, turbulence, and thermal and wind gradients. This propagation prediction is combined with a noise source that can handle fully three-dimensional, spectral source descriptions. The model uses a six-dimensional definition of the source location and orientation to select the radiation angle from the source to the receiver. Levels of audibility of the received signal are then calculated based on the received noise levels, the local ambient noise levels, and the expected listener acuity. Each input to the model has uncertainties with the potential to generate errors that cascade through the system. Differing atmospheric, terrain, and ground impedance conditions have been tested in our model both individually and in combinations to see how they interact. The goal is to have an understanding of the confidence level of audibility provided a known level of uncertainty on the input data. 10:30 3aPA8. Acoustic temperature measurement in a full-scale rocket noise field. Jarom H. Giraud, Kent L. Gee, John E. Ellsworth, and Derek C. Thomas 共Dept. of Phys. and Astronomy, Brigham Young Univ., N283 ESC Provo, UT 84602兲 Acoustic pressure measurements in high-amplitude sound fields are common, but acoustic temperature measurements are relatively rare. This is primarily because thermometers exhibit thermal lag and, consequently, a limited frequency range. In this study, a 1 µ diam platinum wire resistance thermometer was used to measure temperature fluctuations generated by propagating noise produced by a horizontally fired, static GEM-60 solid rocket motor. The data are compared with those calculated from the pressure data of a nearby 3.18 mm condenser microphone by assuming an ideal adiabatic process. 10:45 3aPA9. Rise times of low-energy, free-space propagating acoustic shocks. Thomas B. Gabrielson, Timothy M. Marston 共Graduate Program in Acoust., Penn State Univ., PO Box 30, State College, PA 16804兲, and Mark S. Wochner 共The Univ. of Texas at Austin, Austin, TX 78713-8029兲

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Characteristics of the “ideal” shock, a one-dimensional step change in pressure, are reasonably well established; however, the freely propagating shock with finite duration is challenging to model and measure. These challenges are reflected in an extensive body of literature over several decades. In this paper we present a method for producing free-space propagating shocks, measurements of rise time with minimal contamination by turbulence, and model results that account for spreading, absorption 共including molecular relaxation兲, and nonlinearity. The shocks are produced using an acoustic pipe filter to condition the irregular pressure release of either balloon pops or starter-pistol shots. The shocks range in peak pressure from 10 to 1000 Pa and in rise time from 10 to 0.5 µs. Rise-time measurements are made using a custom piezoelectric polymer wideband microphone with a measurement range that overlaps with that of a diffraction-corrected 1/8inch measurement microphone. The exponential-decay time constant beyond the pressure peak is typically less than 100 µs, which may be too rapid to permit development of characteristics associated with relaxation mechanisms: rise times over the entire range measured here are well predicted by accounting for classical and rotational absorption only.

11:00 3aPA10. Three-dimensional numerical simulation of sonic boom diffraction around buildings using a dispersion-relation-preserving scheme. Sang I. Cho and Victor W. Sparrow 共Grad. Program in Acoust., The Penn State Univ., 201 Appl. Sci. Bldg., Univ. Park, PA 16802兲 A finite difference time domain approach is used to model the temporally and spatially dependent pressure loading on a rigid structure due to an incident low-amplitude N-wave sonic boom. Analytically, one expects strong diffraction due to building corners and pressure doubling near rigid walls. The three-dimensional linear wave equation is sufficient to model the interaction between the structure and the low-amplitude sonic boom at the ground level. Applying a fourth-order dispersion-relation-preserving scheme and a four-level explicit time marching scheme, an excellent dispersion characteristic is achieved without sacrificing computational efficiency of the algorithm. NASA flight testing at Edwards, CA during the summer of 2006 is numerically simulated by matching the geometries of the simulated structure to the actual residential house used for the flight test and using the waveform of a recorded boom as the incoming wave for the simulation. A direct comparison to the experimental data allows the quantitative validation of the simulation results. The feasibility of using this model for calculation of the pressure loads on other structures can be determined based on the accuracy of this numerical solution. 关Work supported by NASA. The authors appreciate NASA making the 2006 and 2007 flight data available for this work.兴



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GALLERIA SOUTH, 8:45 A.M. TO 12:00 NOON Session 3aPP

Psychological and Physiological Acoustics: Impacts of Hearing Impairment Peggy B. Nelson, Chair Dept. of Speech, Language and Hearing Science, Univ. of Minnesota, Minneapolis, MN 55455 Contributed Papers 8:45 3aPP1. A personal perspective on unilateral hearing loss. Brian D. Dushaw 共Appl. Phys. Lab., Univ. of Washington, 1013 N.E. 40th St., Seattle, WA 98105, [email protected]兲 Although I have been unilaterally deaf since birth, only later in life have I realized the extent of this handicap and how I can best manage it. The effects of this hearing loss are complicated, being an interplay of physics, psychology, social interaction, etc. Because people are able to adapt, the extent of this “unseen” handicap is underappreciated. Responses by the public to an informative website 共http://909ers.apl.washington.edu/⬃dushaw/SSD兲 suggest that this handicap has a universal nature. Obvious effects are the inabilities to locate sound or to bilaterally process sound signals. Less obvious effects are a heightened sensitivity to noise: as masking to a desired signal, as a fatigue factor, as an impediment to mental concentration. The difficulties encountered when talking over the telephone to someone who is speaking in a noisy environment may give one an appreciation of the effects. Even less obvious effects are the long-term social implications of the handicap: the tendency to ignore those on one’s deaf side, the inability to function “normally” at noisy events such as parties, ASA receptions, etc., or a tendency to irritability in noisy environments. In this unscientific talk, I will attempt to highlight issues that may be deserving of additional study. 9:00 3aPP2. Masking period patterns of exponentially ramped and damped noises in hearing-impaired listeners. Jennifer Lentz and Yi Shen 共Dept. of Speech and Hearing Sci., Indiana Univ., Bloomington, IN兲 Noises that are modulated with either an exponentially rising 共ramped兲, repeating modulator or a falling 共damped兲, repeating modulator may evoke strong perceptual differences. To explore a possible cochlear contribution to these perceptual differences, masking period patterns 共MPPs兲 of ramped and damped noises were measured for normal-hearing listeners at different stimulus levels and for hearing-impaired listeners. By time-reversing the ramped MPP, comparisons can be made between thresholds for which the masker power was the same between ramped and damped noises. Previous results showed that for normal-hearing listeners, the MPP of a ramped noise is considerably shallower than the MPP of a damped noise. The present results indicated that the differences between the damped and the timereversed ramped MPPs were the largest at moderate stimulus levels and the smallest at low and high stimulus levels. Listeners with hearing loss exhibited no difference in the damped versus time-reversed ramped MPPs. Results will be discussed in terms of contributions of the cochlear nonlinearity and central auditory processes. 9:15 3aPP3. Modulation detection interference in listeners with cochlear hearing loss: Effect of modulation depth and onset delay. Jungmee Lee and Soonha Yook 共Dept. of Speech, Lang. and Hearing Sci., Univ. of Arizona, 1131 E. 2nd St., Tucson, AZ 85721兲 Modulation detection interference 共MDI兲 was measured for listeners with normal hearing 共NH兲 and cochlear hearing loss 共HI兲. The signal was 1 kHz, and the interferer was 2 kHz. The stimuli level was 50 or 22 dB SL. The interferer was modulated with 8 Hz at various modulation depths 共25, 50, 75, or 100%兲. The onset of signal was delayed by 0, 125, 250, 375, 500 or 625 ms relative to onset of the interferer. For NH subjects, MDI increased 2632


systematically with increasing modulation depth of the interferer. MDI almost disappeared with 375 or 500 ms onset delay except a condition with the interferer of 25% modulation depth where there was no MDI at all across different onset delay conditions. In contrast, for HI subjects, there was quite an amount of MDI even with the interferer of 25% modulation depth, and MDI was greater than NH for all modulation depths at 0 and 125 ms onset delays, suggesting that the perceived modulation depth of the interferer might be exaggerated for HI than for NH.

9:30 3aPP4. Frequency modulation detection, frequency selectivity, and speech recognition in noise by hearing-impaired listeners. Van Summers, Matthew Makashay, Joshua Bernstein 共Army Audiol. & Speech Ctr., Walter Reed Army Medical Ctr., 6900 Georgia Ave., NW, Washington, DC 20307兲, Sarah Melamed, and Marjorie Leek 共VA Medical Ctr., Portland, OR 97201兲 Reduced ability to make use of temporal fine structure 共TFS兲 information may contribute to deficits among hearing impaired 共HI兲 listeners for speech recognition in competing background sounds. The broad tuning typically observed in HI listeners will produce more complex patterns of TFS as input to the auditory nerve, and these patterns may be more difficult to encode and/or interpret by higher auditory centers. In the current study, we tested HI listeners on a frequency-modulation 共FM兲 detection task thought to require the use of TFS cues, on tone detection in notched-noise to assess frequency selectivity, and on speech recognition in continuous and modulated background sounds. Performance on the psychoacoustic tasks was tested at four frequencies 共500, 1000, 2000, and 4000 Hz兲 at levels between 60 and 85 dB SPL 共approximating the range of third-octave band levels in the speech stimuli兲. HI listeners with similar audiometric thresholds showed clear differences in frequency tuning, FM detection thresholds, and speech performance. Relationships between the psychoacoustic measures in the four frequency regions and between these measures and speech performance will be discussed.

9:45 3aPP5. Relative contributions of spectral and temporal cues for speech recognition in patients with sensorineural hearing loss. Li Xu, Ning Zhou, Katherine Rife, and Rebecca Brashears 共School of Hearing, Speech and Lang. Sci., Ohio Univ., Athens, OH 45701兲 The present study was designed to examine speech recognition in patients with sensorineural hearing loss 共SNHL兲 when both temporal and spectral information in the speech signals were co-varied. Four subjects with SNHL were recruited to participate in consonant and vowel recognition tests that used speech stimuli processed through a noise-excited vocoder. The number of channels was varied between 2 and 32, which defined spectral information. The lowpass cutoff frequency of the temporal envelope extractor was varied from 1 to 512 Hz, which defined temporal information. Results indicate tremendously individual differences among the subjects with SNHL. For consonant recognition, patterns of relative contributions of spectral and temporal information were similar to those in normal-hearing subjects. The utility of temporal envelope information appeared to be normal in the hearing-impaired listeners. For vowel recognition, the performance plateau was achieved with numbers of channels as high as 16–24, much higher than expected, given that the frequency selectivity in patients with SNHL might be compromised. In order to understand how hearing157th Meeting: Acoustical Society of America


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impaired listeners utilize spectral and temporal cues for speech recognition, future studies will be necessary to elucidate the relationship between frequency selectivity as well as central processing capability and speech recognition performance using vocoded signals. 10:00—10:30 Break 10:30 3aPP6. Discrimination of formant-like glides in gated noise: Effect of sensation level. Peggy Nelson, Yingjiu Nie 共Dept. of Speech-Lang.-Hearing Sci., Univ. of Minnesota, 164 Pillsbury Dr. SE, Minneapolis, MN 55455, [email protected]兲, Magdalena Wojtczak, and Gordon Stecklein 共Univ. of Minnesota, Minneapolis, MN 55455兲 Listeners with sensorineural hearing loss 共SNHL兲 do not experience masking release for speech in fluctuating noise, as normal-hearing listeners do. One hypothesis suggests dip listening may be difficult because frequency glides, or speech formant transitions, may be difficult to discriminate at low sensation levels when in the presence of fluctuating noise. Normalhearing listeners were tested for their ability to discriminate 100-ms frequency glides with center frequencies of 800 and 2500 Hz. They were tested in quiet and in the presence of 500-ms of 8-Hz square-wave gated broadband noise at a signal-to-noise ratio of ⫺10 dB. Listeners were tested at low 共10–15 dB SL兲 and moderate 共30–40 dB SL兲 signal levels. Preliminary results suggest that glide discrimination thresholds 共measured as % change兲 are similar for low- and moderate-level stimuli in quiet; glide thresholds are poorer in gated noise than in quiet; and glide thresholds are poorest when low-level stimuli were presented in gated noise. These results suggest that when formants or glides are presented at low levels and in gated noise, discrimination abilities may be reduced. Implications for understanding masking release for speech by listeners with hearing loss will be discussed. 关Work supported by NIH 5R01DC008306.兴 10:45 3aPP7. Comodulation masking release and speech perception: Implications for dip-listening by cochlear implant patients. Antje Ihlefeld 共MRC Cognition and Brain Sci. Unit, 15 Chaucer Rd, Cambridge CB2 7EF, England, [email protected]兲, Barbara G. Shinn-Cunningham 共Boston Univ., Boston, MA 02215兲, and Robert P. Carlyon 共MRC Cognition and Brain Sci. Unit, Cambridge CB2 7EF, England兲 Compared to normal-hearing 共NH兲 listeners, cochlear implant 共CI兲 listeners struggle to identify speech when a source of noise interferes and do poorly when trying to listen in the dips of a modulated masker. In NH listeners, masker energy outside the spectral region of a target tone can improve target detection, a phenomenon referred to as comodulation masking release 共CMR兲. Here we examined whether a comodulated flanking noise improves speech identification in a modulated noise masker, both for NH listeners identifying vocoded speech and for CI listeners. In experiment 1, NH listeners identified noise-vocoded speech 共taken from a closed-set speech corpus兲 in a background of speech-shaped noise with or without a flanking narrow band of noise outside the spectral region of the target. The masker and flanker were either both 16-Hz square-wave modulated or were unmodulated. Performance was better in modulated than in unmodulated noise and, importantly, this difference was greatest when the comodulated flanker was present, consistent with the idea that CMR can introduce segregation cues between target and masker that help to listen in the dips of the masker. Experiment 2 tested CI listeners with the same experimental paradigm. 11:00 3aPP8. Masking release for speech in listeners with real and simulated hearing impairment. Joseph G. Desloge, Charlotte M. Reed, Louis D. Braida, Zachary D. Perez, and Lorraine A. Delhorne 共Res. Lab. of Electron.s, Massachusetts Inst. of Technol., 77 Massachusetts Ave., Cambridge, MA 02139, [email protected]兲 The current study examined the effects of audibility and age on the release of masking for speech in interrupted versus steady-state noise in listeners with real and simulated hearing loss. The absolute thresholds of each 2633


of ten hearing-impaired listeners were simulated in normal-hearing listeners through a combination of spectrally shaped masking noise and multiband expansion for the octave bands with center frequencies from 0.25–8 kHz. Each individual hearing loss was simulated in two groups of three normalhearing listeners 共one age-matched group and one non-age-matched group兲. The speech-to-noise ratio 共S/B兲 for 50%-correct identification of HINT sentences was measured in backgrounds of steady-state noise and temporally modulated 共10-Hz square-wave兲 noise at two overall levels for unprocessed speech and for speech that was amplified with the NAL-PR prescription. Results indicate that the magnitude of the release from masking 共the difference in S/B obtained in steady-state versus interrupted noise兲 observed in individual hearing-impaired listeners was generally well produced in both groups of simulated-loss listeners. Thus, release of masking appears to be determined primarily by audibility regardless of age. Predictions of masking release derived from the Speech Intelligibility Index 共SII; ANSI S3.5-1997兲 will be compared to the observed values. 关Work supported by NIH-NIDCD R01 DC00117.兴

11:15 3aPP9. Spectral modulation detection training in older adults with hearing loss. Andrew T. Sabin, Cynthia A. Clark 共Dept. of Commun. Sci. and Disord., Northwestern Univ., 2240 Campus Dr. Evanston, IL 60201, [email protected]兲, David A. Eddins 共Univ. of Rochester, Rochester, NY 14618兲, Sumitrajit Dhar, and Beverly A. Wright 共Northwestern Univ., Evanston, IL 60201兲 Individuals with hearing loss are poorer than normal-hearing listeners at detecting patterns of peaks and valleys of sound level spread across audio frequency 共spectral modulation detection兲—an important skill for speech and music perception. In this preliminary report we examined whether listeners with hearing loss could improve on spectral modulation detection with practice. We trained older adults with sensorineural hearing loss 共n⫽7兲 ⬃1 hr/day for 7 days to distinguish a 400–3200 Hz noiseband with a flatspectrum from one with a 2 cyc/oct sinusoidal spectral modulation. Modulation depth was varied adaptively to determine the detection threshold. Their mean thresholds improved significantly from 18.9 to 12.8 dB. These listeners also improved at both a lower and a higher untrained spectral modulation frequency 共1 and 4 cyc/oct兲, but showed no change on a measure of frequency selectivity. Interestingly, a separate group of younger normalhearing adults who received the same training 共n⫽7兲 did not improve on the trained 共6.9 to 6.6 dB兲 or untrained conditions. Normal-hearing listeners had lower pre-training thresholds than individuals with hearing loss, and across all listeners the magnitude of individual improvement was correlated to pretraining threshold 共r⫽0.92兲. Listener age and/or hearing loss could have contributed to these across-population differences.

11:30 3aPP10. Multidimensional perceptual scaling of musical timbre by hearing-impaired listeners. Kelly Fitz, Matt Burk, and Martin McKinney 共Starkey Labs, 6700 Washington Ave., S., Eden Prairie, MN 55344, kellyគ[email protected]兲 We examine the impact of hearing loss and hearing aid processing on the perception of musical timbre. Our objective is to identify significant timbre cues for hearing-impaired listeners, and to assess the impact of hearing aid signal processing on timbre perception. Hearing aids perform dynamic, level-dependent spectrum shaping that may influence listeners’ perception of musical instrument timbres and their ability to discriminate among them. Grey 关“Multidimensional perceptual scaling of musical timbres,” J. Acoust. Soc. Am. 61, 1270 共1977兲兴 showed that sustaining instrument tones equalized for level, loudness, and duration are distinguished primarily along three perceptual dimensions that are strongly correlated with the acoustical dimensions of: 共1兲 spectral energy distribution, 共2兲 spectral fluctuation, and 共3兲 precedent high-frequency, low-amplitude energy. Following the work of Grey, we ask listeners having mild to moderately severe sensorineural hearing loss to rate pairs of synthetic musical instrument tones according to dissimilarity in aided and unaided conditions. We analyze the dissimilarity judgments to identify acoustical correlates for the significant dimensions of timbre discrimination. This analysis helps us to objectively estimate the impact of hearing aid signal processing on the ability of hearing-impaired lis157th Meeting: Acoustical Society of America


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teners to discriminate among musical instruments, an important component of musical listening. 11:45 3aPP11. The perceptual tone-noise ratio of iterated rippled noise in listeners with hearing loss. Marjorie R. Leek, Sarah Melamed, Michelle R. Molis, and Frederick J. Gallun 共Natl. Ctr. for Rehab. Aud. Res., Portland VA Medical Ctr., 3710 SW US Veterans Hospital Rd., Portland, OR 97239兲 Previous work has demonstrated that iterated rippled noise 共IRN兲 produces a weaker pitch in hearing-impaired 共HI兲 listeners than in normalhearing 共NH兲 subjects 共e.g., Leek and Summers, 2001兲. In this study, the hypothesis was tested that the weaker pitch is a result of an increased per-

ceptual noisiness of IRN for HI subjects. The tone-noise ratio 共T/N兲 was developed by Patterson et al. 共1996兲 to describe the relationship between the strength of the tone component and the strength of the noise component for a given IRN. The T/N was measured using an adaptive procedure to find the tone-plus-noise level that matched each IRN stimulus. Four NH and 4 HI subjects took part in the study. The stimuli were IRNs with delays ranging from 4 to 16 ms and with one to eight iterations. There was a significant effect of delay and of iteration number, with longer delays and more iterations producing greater T/N. There were no significant differences between subject groups. These findings suggest that the weaker complex pitch observed in listeners with hearing loss is not due to an abnormally noisy IRN percept but must be attributed to other impaired processing mechanisms. 关Work supported by NIH.兴


FORUM SUITE, 8:30 A.M. TO 12:00 NOON Session 3aSA

Structural Acoustics and Vibration: General Structural Acoustics Rudolph Martinez, Chair CAA-Alion Corp., 84 Sherman St., Cambridge, MA 02140 Contributed Papers 8:30 3aSA1. Scan-based near-field acoustical holography on partially correlated fields: Theory and numerical experiments.Michael D. Gardner, Kent L. Gee, Alan T. Wall, Scott D. Sommerfeldt 共Dept. of Phys. and Astronomy, Brigham Young Univ., N283 ESC, Provo, UT 84602兲, Daniel Manwill, and Jonathan D. Blotter 共Brigham Young Univ., Provo, UT 84602兲 Conventional near-field acoustical holography 共NAH兲 requires a coherent field. For a coherent source, a scan-based approach can be used with one reference microphone to stitch the phase. For a noncoherent field, scanbased NAH can be performed if the virtual coherence technique is used. This technique uses multiple reference microphones to decompose the partial field into mutually uncorrelated partial fields, which are then processed by some NAH method. In particular, the statistically optimized near-field acoustical holography 共SONAH兲 method is used with modified Tikhonov regularization. Numerical experiments are performed on a series of point sources with source strengths chosen to mimic the source characteristics of high-powered jets. The experiments are designed to aid in determining the proper number and location of reference microphones for doing NAH work on high-powered jet noise. 关Work supported by Blue Ridge Research and Consulting and the Air Force Research Laboratory.兴

8:45 3aSA2. Scan-based near-field acoustical holography on partially correlated fields: Laboratory experiments. Alan T. W, Michael D. Gardner, Kent L. Gee, Scott D. Sommerfeldt 共Dept. of Phys. and Astron., Brigham Young Univ., N283 ESC, Provo, UT 84602, [email protected]兲, Daniel Manwill, and Jonathan D. Blotter 共Brigham Young Univ., Provo, UT 84602兲 Forms of near-field acoustical holography 共NAH兲 can be applied to source reconstructions of arbitrarily correlated extended sources, such as jet exhaust plumes. Prior to implementing NAH to reconstruct the jet noise source region of a military jet aircraft, laboratory experiments are being performed. These experiments utilize statistically optimized NAH 共SONAH兲, coupled with the virtual coherence method, to reconstruct the radiation from correlated, partially correlated, and uncorrelated loudspeakers. Results from these experiments will be shown. Reconstructions of this type require the use of multiple reference microphones. However, little is known 2634


about how many should be used or where they should be placed. Successful reference placement strategies are being explored and commentary on these results will also be given. 关Work supported by Blue Ridge Research and Consulting and the Air Force Research Laboratory.兴

9:00 3aSA3. Near-field acoustic holography in conical coordinates. Tracianne B. Neilsen, Kent Gee, and Michael Gardner 共Dept. of Phys., Brigham Young Univ., Provo, UT 84602, tbn@byu,edu兲 Near-field acoustical holography 共NAH兲 techniques can be optimized if the method capitalizes on the geometry of the noise source under investigation. Helmholtz-equation least squares method 共HELS兲 uses the solutions of Helmholtz equation in spherical coordinates as basis functions for the pressure field. HELS is an efficient NAH technique if the source and the measurement surfaces are spherical in nature. For nonspherical cases, such as radiation from a plate or bar, it takes a large number of functions to represent the field. In these cases, there is also a question about where to place the origin of the wave functions. In search of a HELS-type method that could be applied to nonspherical sources, a study into the features of conical coordinates has been conducted. Because the Helmholtz equation is separable in conical coordinates, the solutions can be used, in a manner similar to HELS, as basis functions to represent the pressure field. For conical coordinates, the basis functions are spherical Hankel functions and Lame functions. This HELS-type formulation in conical coordinates could be a natural choice for NAH on conical sources and may be appropriate for NAH on jet noise. 关Work supported by Blue Ridge Research and Consulting and Air Force Research Laboratory.兴

9:15 3aSA4. Determination of ultrasonic vibration modes of a graded solid cylinder using a modified wave-expansion technique. Betsabe Manzanares-Martinez 共Div. de Ciencias e Ingeniería, Unidad Regional Sur de la Universidad de Sonora, Boulevard Lzaro Crdenas 100, Navojoa, Sonora 85880, Mexico, [email protected]兲, Jin-Yeon Kim 共Georgia Inst. of Technol., Atlanta, GA 30322-0355兲, and Arturo Baltazar 共CINVESTAV-Saltillo, Ramos Arizpe, Coahuila 25900, Mexico兲 Research on wave propagation in cylinders—hollow, solid, or graded—has been driven by its potential use in the inspection of long-span 157th Meeting: Acoustical Society of America


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engineering structures. Its practical application largely depends on the understanding of modal vibration inside the structure. Typically, the plane wave approach is used to model phase velocity, group velocity and dispersion curves in periodic systems. This proves cumbersome when used to model finite periodic structures, semifinite plates, or concentric cylinders. Here, a simpler approach to determine the vibration modes and dispersion curves of a solid concentric cylinder using a modified wave-expansion approach, used mostly in phononic crystals research, is proposed. The advantage of this technique is the possible application on a wide variety of cylindrical geometries and graded structures with various transverse sections. The results of the proposed technique are compared with those obtained by the resonance scattering theory for the simple case of a solid cylinder with a single core having different mechanical properties. 关Work partially sponsored by SEP-CONACYT through project # 58951. 9:30 3aSA5. Three component time reversal imaging using nonlinear elasticity. Timothy J. Ulrich, II, Pierre-Yves Le Bas, Robert A. Guyer 共Los Alamos Natl. Lab., EES-17, MS D443, Los Alamos, NM 87545, [email protected]兲, Brian E. Anderson 共Brigham Young Univ., Provo, UT兲, Michele Griffa 共EMPA, Duebendorf, Switzerland兲, and Koen Van Den Abeele 共Katholieke Univ. Leuven Campus Kortijk, Kortrijk, Belgium兲 The time reversed elastic nonlinearity diagnostic 共TREND兲 has been shown to have the ability to image near surface nonlinear scatterers 共e.g., cracks and disbonds兲 using the normal 共out of plane兲 component of motion. This technique has been advanced with the addition of three-component vector wave field detection using laser vibrometry. This advancement provides the ability of TREND to detect and image features of various orientations, increasing its capability and decreasing the likelihood of overlooking features due to the inability to excite them. Furthermore, the ability to selectively focus each component of motion provides the means to investigate the mechanism of the nonlinear wave generation at the nonlinear scattering sites. Experimental data are presented from samples containing known defects 共location and orientation兲 confirming the sensitivity of threecomponent time reversal imaging in both linear and nonlinear ultrasonics to feature orientation. 9:45 3aSA6. Parameter study for Structural Health Monitoring based on ambient noise cross-correlation. Najib Abou Leyla, Emmanuel Moulin, Jamal Assaad, Sebastien Grondel, and Christophe Delebarre 共UVHC, IEMN-DOAE, Le Mont Houy, 59313 Valenciennes, France兲 The possibility of performing Structural Health Monitoring in aeronautic structures using ambient noise cross-correlation techniques has been investigated in previous works. The applicability of such methods has been validated by checking the reproducibility and the potential in terms of damage detection. In this paper, a more detailed description of the acoustic phenomena involved is given. The influence of the different parameters 共source characteristics, sensors and damage positions, etc.兲 on the cross-correlation function has been studied. A theoretic study is presented and used to develop a simple simulation tool based on multipath reflections of ballistic waves. The simulated results have been successfully compared to finite element results in simple cases. This tool is then exploited to characterize and quantify the influence of the significant parameters. Finally, some optimization solutions of the technique are proposed, and experimentally validated. 10:00—10:15 Break 10:15 3aSA7. Detection of structural faults in pipelines with time reversal. Nicholas A. O’Donoughue, José M. F. Moura 共Dept. of Elect. & Comput. Eng., Carnegie Mellon Univ., 5000 Forbes Ave., Pittsburgh, PA 15217, nodonoug,[email protected]兲, and Yuanwei Jin 共Univ. of Maryland Eastern Shore, Princess Anne, MD 21853兲 The volatile nature of natural gas makes it extremely important to ensure that transport and distribution pipelines remain free from defects, as leakage can result in explosions. Current methods for testing buried pipelines rely on 2635


periodic excavation of a section of pipe and attachment of large acoustic or magnetorestrictive sensors. These systems, while reliable, suffer from a high cost-per-test ratio. To reduce the power requirements, we consider ultrasound embedded devices that could monitor the pipelines continuously. The problem with ultrasound is that, with buried pipes, the propagation is highly dispersive. We propose to use time reversal 共TR兲, a signal processing technique, to refocus the signals and use, to our advantage, the dispersive nature of the environment. This paper will focus on the modes generated by various acoustic probing signals and the echoes received with and without TR. We argue that TR will be most beneficial when there are several dispersive modes present, a scenario avoided in conventional techniques. We will present simulation results for the detection of faults in a pipeline using PZFlex. 10:30 3aSA8. Acoustic detection of bolt detorquing in structures. Joe Guarino 共Dept. of Mech. and Biomedical Eng., Boise State Univ., Boise, ID 837252075, [email protected]兲 and Robert Hamilton 共Boise State Univ., Boise, ID 83725-2075兲 Recent interest in structural health of bridges and large buildings has lent new urgency to the development and enhancement of theories and methods in the field of nondestructive testing. We demonstrate a simple technique for acquiring data from an impact test using a basic electronic stethoscope. The continuous wavelet transform 共CWT兲 is used to process and display the transient responses of a bolted joint in a structure with bolts installed in a properly tightened manner and bolts incorrectly installed. Results for tight and loose bolts are compared using the semblance analysis approach described by Cooper and Cowan 关“Comparing time series using wavelet-based semblance analysis,” Computers & Geosciences 34, 95–102 共2008兲兴. We enhance the interpretation of results using speaker-driven audio output synthesized from CWT and semblance analysis. 10:45 3aSA9. Selective excitation of microcantilever array using ultrasound radiation force. Thomas M. Huber, Daniel C. Mellema, and Brad Abell 共Dept. of Phys., Gustavus Adolphus College, 800 College Ave., St. Peter, MN 56082兲 The symmetric and antisymmetric eigenstates of a coupled pair of 500 956 m length microcantilevers were excited using the ultrasound radiation force. The excitation was produced using the difference frequency between the two sidebands of a double sideband suppressed carrier AM 共DSB-SCAM兲 waveform centered on 500 kHz that was emitted by a pair of focused ultrasound transducers. A laser Doppler vibrometer measured the frequency response and deflection shapes of the cantilever pair. When the waveforms sent to the transducer resulted in radiation force from both transducers with the same phase, it excited the 10.00 kHz symmetric state of the cantilever array while suppressing the 10.17 kHz antisymmetric state. Similarly, when the radiation force from the two transducers was 180 degrees out of phase, it selectively excited the antisymmetric state while suppressing the symmetric state. This ability to selectively excite different vibrational eigenstates is a unique capability of this noncontact for modal excitation. 11:00 3aSA10. Limiting performance of active vibration compensation in free multi-degree-of-freedom mechanical systems. Vyacheslav Ryaboy 共Newport Corp., 1791 Deere Ave., Irvine, CA 92606, vyacheslav.ryaboy @newport.com兲 Examples of free 共not supported兲 mechanical system requiring active vibration control range from space structures to vibration-isolated platforms for sensitive equipment. While active damping systems reducing resonance vibrations of the structure received significant attention and reached practical implementation, active vibration compensation, or cancellation of forced vibration, is still problematic in complex systems. In this work, active vibration compensation is considered in frame of limiting performance approach that aims at estimating the best results attainable in the whole class of linear multi-degree-of-freedom systems. Several design goals are considered, including absolute and relative displacements of various points of the system. The resulting estimates are valid for all possible sets of internal ac157th Meeting: Acoustical Society of America


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11:30 3aSA12. Wave vector method for estimating acoustic vector quantities. Derek C. Thomas and Kent L. Gee 共Dept. of Phys. and Astronomy, Brigham Young Univ., N283 ESC, Provo, UT 84602兲

tive forces. The limiting performance is estimated in terms of frequency domain and work performed by active forces on system displacements, which is considered a measure of the control effort. These estimates are expressed as exact inequalities in explicit analytical form. Active force distributions emerging from limiting performance analyses can assist in finding rational system configurations and optimal controls. Minimum active work, expressed in terms of passive subsystem parameters, provide a criterion for optimization of a structure as a potential host for an active vibration control system.

Acoustic vector quantities such as particle velocity and intensity are usually estimated using the finite-difference technique. We present an alternate method, termed the wave vector method, for estimating vector quantities in acoustic fields in which the reactive intensity is small relative to the active intensity. This method utilizes the same equipment necessary for the finitedifference method, yet reduces sensitivity to sensor phase mismatch at low frequencies and eliminates bias error at high frequencies. The method is developed for arbitrary sensor configurations, and numerical results are presented for the special case of a regular tetrahedral configuration. 关Work supported by NASA Stennis Space Center and STI Technologies.兴

11:15 3aSA11. Response of a simple system made complex by attaching subsystems—an analytic study. John J. McCoy 共School of Eng., The Catholic Univ. of America, Washington, DC 20064兲

11:45 3aSA13. Impact of spherical probe scattering on estimation of acoustic vector quantities. Curtis P. Wiederhold 共Dept. of Mech. Eng., Brigham Young Univ., 435 Crabtree Bldg., Provo, UT 84602, [email protected]兲, Kent L. Gee, Derek C. Thomas, Scott D. Sommerfeldt 共Brigham Young Univ., Provo, UT 84602兲, and Jonathan D. Blotter 共Brigham Young Univ., Provo, UT 84602兲

A deceptively simple dynamical system comprised of a grounded mass to which are attached N, a large number, sprung masses has received much attention. The reported studies mostly involve physical experiments or numerical simulations. Given the large number of physical parameters needed to describe any single system, such a research agenda requires one to address an excessive number of experiment scenarios. Thus, the motivation for the analytical study reported. The focus of the study is the net force the attached subsystems cause to act on the base system. This force, while “internal” to the coupled system, is a response measure of primary importance since it accomplishes the work that determines the energy flow to and from the base system. As demonstrated, a further reason for the focus is an ability to construct an asymptotically valid, analytic expression for this response measure. Further demonstrated, using the constructed expression, is a resolution of a complex “process,” that describing the energy flow to the system, by the action of an external forcing, and through the system, as a combination of simple “sub-processes.” The resolution requires describing the complex process in a time/frequency phase space; the sub-processes are “local” in the phase space.

Multimicrophone probes are often used to measure energy-based acoustical quantities. In some cases, these probes consist of microphones mounted on the surface of a sphere, which, due to the high level of symmetry, permits scattering effects to be better characterized. Scattering of a plane wave incident on a rigid sphere has been modeled to observe how particle velocity and intensity calculations are affected by the presence of the sphere. These effects have been investigated for the traditional “finite-difference” method and a recently developed “wave vector” estimation method. In the computer model, 3-D surface plots were made showing the calculated error as a function of angle of the incident plane wave and frequency. It is shown that using the wave vector method and purposefully orienting the probe in the planar sound field generally results in the most accurate measurements. 关Work supported by NASA Stennis Space Center and STI Technologies.兴


GRAND BALLROOM I, 8:00 TO 11:50 A.M. Session 3aSC

Speech Communication, Musical Acoustics, and Animal Bioacoustics: Source/Filter Interaction in Biological Sound Production (Lecture/Poster Session) Ingo R. Titze, Chair Dept. of Speech Pathology and Audiology, Univ. of Iowa, Iowa City, IA 52242-1012 Chair’s Introduction—8:00

Invited Papers 8:05 3aSC1. Modulation of birdsong by resonance filters in the suprasyringeal vocal tract. Roderick A. Suthers 共Medical Sci. and Dept. Biology, Indiana Univ., 1001 E. Third St., Bloomington, IN 47405, [email protected]兲 The sound generated in the avian vocal organ, the syrinx, is modified by the filter properties of the upper vocal tract before it radiates from the beak as song. Previous investigators have shown that the properties of this vocal tract filter are affected by changes in beak gape, but the basis of this effect remains controversial. In the present study, x-ray cinematography of singing birds was used to investigate the filter properties of the suprasyringeal vocal tract. These experiments show that the dimensions of the oropharynx and esophagus are actively controlled during song by motor patterns involving muscles of the hyoid apparatus. These song-related motor patterns, together with movements of the tongue, which modulate the opening from the mouth into the beak, adjust in real time the volume and 2636




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dimensions of the oropharynx and cervical esophagus so that the primary acoustic resonance of the upper vocal tract supports and tracks the fundamental frequency that is being generated by the syrinx. In juvenile Northern Cardinals, these song-related movements of the upper vocal tract first appear during subsong, while the beak is closed, and precede the changes in beak gape that typically accompany adult song. 关Work supported by NIH.兴

8:35 3aSC2. Source-filter interactions in birds—Theory and experimental evidence. Gabriel Mindlin, Ezequiel Arneodo 共Dept. of Phys., Univ. of Buenos Aires, [email protected]兲, and Franz Goller 共Univ. of Utah, Salt Lake City, UT, [email protected]兲 The diverse acoustic behavior of birds presents a rich source of natural vocalizations, some of which most likely reflect source-filter interaction. However, very little experimental evidence exists for the specific role of such interactions in shaping acoustic behavior or the functional relevance of the resulting acoustic features. As an example of how theoretical approaches can help explain acoustic observations, we discuss coexisting limit cycles in relaxation oscillators subjected to delayed feedback. The dynamical solutions of a nonlinear relaxation oscillator subjected to a delayed feedback are analyzed, and the equations under study are designed to model some aspects of the source-tract interaction in birdsong production. By deriving a phase equation for the system and analyzing its solutions, we are able to unveil analytical relationships between the parameters that lead to a variety of solutions. In particular, we study the coexistence of periodic solutions for similar pitch and first formant frequencies. These dynamical situations allow us to interpret the frequency jumps present in some birdsong syllables as an effect of the interaction between the source and the tract.

9:05 3aSC3. The epilaryngeal tube and air sacs in mammals as acoustic couplers—A review. Tobias Riede 共Dept. of Biology, Univ. of Utah, 257 S 1400 E, Salt Lake City, UT 84112, [email protected]兲 and Isao Tokuda 共Japan Adv. Inst. of Sci. and Technol., Ishikawa, Japan兲 The intralaryngeal space between glottis and the cranial edge of the larynx is called the epilaryngeal tube 共synonyms are vestibulum larynges or supraglottal intralaryngeal space兲. Research on larynx models and in humans indicate that this part of the vocal tract filter can contribute to two important acoustic effects: 共a兲 the singer’s formant and 共b兲 the enhancement of nonlinear source-filter coupling. The acoustic role of this structure in nonhuman mammals is unknown. Furthermore, in many species tube and sac-like cavities are attached to the epilaryngeal tube 共laryngeal air sacs兲 and their function is equally little understood. In this presentation I will report on results testing the hypothesis that the shape 共length and diameter兲 of the epilaryngeal tube in nonhuman mammals is related to morphological parameters 共vocal fold morphology, larynx size, body size兲 and parameters characterizing the species vocal repertoire 共repertoire size, maximum sound amplitude, fundamental frequency range, occurrence of nonlinear phenomena兲. Preliminary results indicate that the length of the epilaryngeal tube is a poor predictor of repertoire characteristics such as maximum sound amplitude and fundamental frequency range. However, species with a prominent epilaryngeal tube produce a large proportion of high fundamental frequency call types.

9:35 3aSC4. A possible role of nonlinear source-filter interaction in simulation of childlike speech. Brad H. Story 共Dept. Speech, Lang., Hearing Sci., Univ. of Arizona, P.O. Box 210071, Tucson, AZ 85721兲 Simulation 共or synthesis兲 of natural-sounding childlike speech has long been a challenge. This is likely due, at least in part, to an incomplete understanding of the nonlinear interaction of the voice source and the vocal tract filter. Speech production by children is typically characterized by a fairly high fundamental frequency of phonation and a short vocal tract length that produces high formant frequencies. Together, these two characteristics suggest that low-numbered harmonics 共including the fundamental frequency兲 may often, or even necessarily, be in close proximity to one or more of the formant frequencies. Such conditions may lead to a strong interaction of the acoustic pressures in the vocal tract and the glottal airflow, and possibly the vibration of the vocal folds. The purpose of this study was to use kinematic models of the vocal folds and vocal tract shape, scaled to approximately represent a 5-year-old child, to generate individual vowels and sentences. Waveshape and harmonic content of glottal area, glottal flow, and radiated acoustic pressure signals were compared across three vowels and one sentence. 关Research supported by NIH R01-DC04789.兴 10:05—10:20 Break

10:20 3aSC5. Nonlinear source-tract interaction in singing. Ingo R. Titze 共Dept. of Commun. Sci. and Disord., Univ. of Iowa, WJSHC, Iowa City, IA 52242 [email protected]兲 Most approaches to teaching singing are based on concept that there preferred vowel configurations for a given pitch. Speaking vowels are modified not only to create a variety of timbres, but also to support the sound source in self-sustained oscillation. Linear filter theory, traditionally applied to cans or strengthening by vocal tract coupling, or can it account for source bifurcations in vocal fold oscillation related to vowel selection. Singing are contrasted by selection of two fundamentally different mouth configurations, the megaphone shape and the inverted megaphone shape. With the megaphone shape 共used by musical theatre and jazz兲, the second harmonic of the sound source is reinforced at all high pitches by keeping the first formant frequency high. With the inverted megaphone shape 共used by classical singers of opera and art song兲, the second and third harmonics are reinforced by the second formant. A “lift” of the second harmonic over the first formant becomes a critical skill in acquiring a smooth timbre over a wide pitch range. 关Work supported by NIH.兴 2637




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Contributed Papers All posters will be on display from 10:50 to 11:50. To allow contributors an opportunity to see other posters, contributors of oddnumbered papers will be at their posters from 10:50 a.m. to 11:20 a.m. and contributors of even-numbered papers will be at their posters from 11:20 a.m. to 11:50 a.m. 3aSC6. Subglottal effects on the vowels across language: Preliminary study on Korean. Youngsook Jung 共Speech Commun. Group, MIT, Cambridge, MA 02139, and Harvard-MIT Div. of Health Sci. and Technol., Cambridge, MA 02139兲 Previous research suggested that subglottal resonances define vowel features 关back兴 and 关low兴 for English. In testing this hypothesis, we explored whether these vowel feature boundaries are independent of language. As preliminary research, we made recordings of speech and subglottal signals simultaneously for several adult Korean speakers. We found acoustic irregularities in F1 and F2 near subglottal resonances in Korean vowels. The boundary between 关⫹low兴 and 关⫺low兴 vowels agrees with speakers’ first subglottal resonances 共SubF1兲, while the boundary between 关⫹back兴 and 关⫺back兴 agrees with SubF2. In addition, we tested which of these hypotheses is correct for a low vowel in Korean, which has only one low vowel with no contrast of 关⫹back兴 and 关⫺back兴: 共1兲 the low vowel is always 关⫹back兴 or 共2兲 SubF2 is avoided but the low vowel is front or back depending on adjacent consonants. The measurements of F2 and F2sub were obtained in the context /CaC/, where C is a consonant. We found that SubF2 was always avoided for the low vowel. If the adjacent consonants were labial or velar, F2 of the low vowel was below SubF2, whereas if the consonants were alveolar, F2 of the vowel was above SubF2. 关Supported by NIH /NIDCD Grant No. #DC00075.兴 3aSC7. Automatic classification of consonant-vowel transitions based on subglottal resonances and second formant frequencies. Nancy F. Chen and Steven M. Lulich 共Speech Commun. Group, MIT, 77 Massachusetts Ave., Cambridge, MA 02139兲 A growing body of work indicates that subglottal resonances 共SGRs兲 divide the frequency space of vowels and consonants into distinct regions in several languages 关S. Lulich, J. Phonetics 共in press兲, and references therein兴. For instance, the second formant frequency 共F2兲 of back vowels lies between the first and second subglottal resonances 共Sg1 and Sg2兲, while for front vowels F2 lies at higher frequencies than Sg2. In alveolar stop bursts, F2 lies between Sg2 and the third subglottal resonance 共Sg3兲. In this study, we build on previous work 关S. Lulich, JASA 124, 2558 共2008兲兴 to automatically determine SGRs using locus equations computed from 405 consonantvowel 共CV兲 transitions produced by an adult male native speaker of American English. Consonants and vowels are then classified into place of articulation and front/back features based only on the relations between F2 and the SGRs. The mean hit rate across categories was 77%, while the mean false alarm rate was 12%. These results show relative improvements of miss and false alarm rates by 21% and 14% from a baseline experiment, where F2 without SGRs was used to perform the classification. Our knowledgebased approach of classifying CV transitions is potentially useful when vowel and consonant identities are unavailable. 3aSC8. Source-filter interaction in the opposite direction: Subglottal coupling and the influence of vocal fold mechanics on vowel spectra during the closed phase. Steven M. Lulich 共Speech Commun. Group, MIT, 77 Massachusetts Ave., Cambridge, MA 02139, [email protected]兲, Matias Zanartu 共Purdue Univ., West Lafayette, IN 47907兲, Daryush D. Mehta 共Harvard-MIT Div. of Health Sci. and Technol., Cambridge, MA 02139兲, and Robert E. Hillman 共Harvard Med. School, Boston, MA 02114兲 Studies of speech source-filter interaction usually investigate the effect of the speech transfer function 共loading兲 on vocal fold vibration and the voice source. In this study we explore how vocal fold mechanics affect the transfer function throughout the glottal cycle, with emphasis on the closed phase. Coupling between the subglottal and supraglottal airways is modulated by the laryngeal impedance. Although coupling is generally thought to occur only during the open phase of vocal fold vibration, a posterior glottal opening and the vocal fold tissue itself can allow sound transmission, thereby introducing coupling during the closed phase as well. The impedance of the vocal fold tissue at closure is shown to be small enough to permit coupling throughout the phonatory cycle, even in the absence of a pos2638


terior glottal opening. Open- and closed-phase coupling is characterized using mathematical models of the subglottal and supraglottal airways, and the parallel laryngeal impedances of the membranous glottis, posterior glottal opening, and vocal fold tissue. Examples from sustained vowels are presented, using synchronous recordings of neck skin acceleration, laryngeal high-speed videoendoscopy, electroglottography, and radiated acoustic pressure. 3aSC9. Nonlinear flow-structure coupling in a mechanical model of the vocal folds and the subglottal system. Michael S. Howe 共College of Eng., Boston Univ., 110 Cummington St., Boston, MA 02215兲 and Richard S. McGowan 共CReSS LLC, Lexington, MA 02420兲 An analysis is made of the nonlinear interaction between flow in a mechanical model of the subglottal vocal tract and a model of the vocal folds. The mean flow through the system is produced by a “lung cavity” that is assumed to be steadily contracting. The lungs are connected to a subglottal tube of length L. The model for the vocal folds is at the other end of the subglottal tube. This model is a simple, self-exciting single-mass mathematical model of the vocal folds used to investigate the sound generated within the subglottal domain and the unsteady volume flux from the glottis. In the case when the absorption of sound by the lungs is presumed small and when the subglottal tube behaves as an open ended resonator 共when L is as large as half the acoustic wavelength兲 a mild increase in volume flux is predicted. However, the strong appearance of second harmonics of the acoustic field is predicted at intermediate lengths, when L is roughly a quarter of the acoustic wavelength. In the cases of large lung damping, however, only modest changes in volume flux are predicted to appear. 关Work supported by DC009229 to UCLA under subcontract.兴 3aSC10. An impedance-based inverse filtering scheme with glottal coupling. Matias Zanartu 共School of Elect. and Comp. Eng., Purdue Univ., 206 S. Martin Jischke Dr., West Lafayette, IN 47907, [email protected]兲, Julio C. Ho 共Purdue Univ., West Lafayette, IN 47907兲, Daryush D. Mehta 共Harvard-MIT Div. of Health Sci. and Technol., Cambridge, MA 02139兲, Robert E. Hillman 共Massachusetts General Hospital, Boston, MA 02114兲, and George R. Wodicka 共Purdue Univ., West Lafayette, IN 47907兲 Source-filter interactions in voice production arise from considering finite glottal impedances that are comparable with that of the vocal tract and/or the subglottal system. Besides the changes in the source behavior, finite glottal impedances also allow for acoustic coupling between the subglottal and supraglottal tracts. Vowel dependence on the subglottal acoustic pressure is evident in recordings of skin acceleration overlying the suprasternal notch. To obtain estimates of other physiologic signals from skin acceleration, an impedance-based inverse filtering scheme that considers acoustic coupling is proposed. The scheme is based on an electrical analog model of a dipole source and assembles multiple approaches to estimate the system impedances. An experimental platform considers simultaneous measurements of skin acceleration, flexible high-speed videoendoscopy, oral volume velocity, intraoral pressure, electroglottography, and radiated acoustic pressure. Recordings of sustained vowels, co-articulated gestures, and pitch glides provide a comprehensive data set to study tract coupling and sourcefilter interactions. Preliminary results provide insights into the interrelation among the measured signals and illustrate the tissue instabilities of the vocal folds during some of the gestures. Further evaluation in cases of vocal fold pathology is also planned, where source-filter interactions are expected to be even more pronounced. 3aSC11. Vocal inharmonicity analysis: A promising approach for acoustic screening for dysphonia. Samuel Matteson 共Dept. of Phys., Univ. of North Texas, 1155 Union Circle 311427, Denton, TX 76203-5017, [email protected]兲 and Fang-Ling Lu 共Univ. of North Texas, Denton, TX 76203-5017兲 157th Meeting: Acoustical Society of America


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In the United States, 6.8% of men, women, and children report voice problems currently, while during their lifetime ca. 29% will complain of some dysphonia, often due to pathologies of the vocal folds. The authors 共a physicist and a speech pathologist兲 describe an interdisciplinary approach that exhibits promise for detecting physiological abnormalities of the vocal folds from a spectral analysis of the overtone series of spoken tokens. This preliminary investigation shows that the normal human vocal fold emits overtones that are very nearly precise integral values of the fundamental. Physiological problems of the vocal folds, however, introduce mechanical nonlinearities that manifest themselves as frequency deviations from the ideal harmonic 共that is, integral兲 values. The authors quantify this inharmonicity, describing and illustrating how one can efficiently obtain and analyze such data. They outline, as well, a proposed investigation to assess the clinical sensitivity and significance of the analysis discussed in this work in conjunction with laryngoscopic diagnosis of pathology.

were further supported by experiments using a self-oscillating physical model. The result of this study confirms previous findings that phonation onset occurs as a matching between the flow stiffness, which is proportional to subglottal pressure, and vocal fold stiffness, which scales with natural frequency squared and depends on geometry and boundary conditions of the vocal fold structure as well as material properties of the vocal folds. 关Work supported by NIH.兴 3aSC13. Analysis and synthesis of humpback whale songs. Pranab K. Dhar, Sangjin Cho, Jong-Myon Kim, and Uipil Chong 共Univ. of Ulsan, Ulsan 680-749, Korea兲 The humpback whale song is one of the most complex, non-human, acoustic displays in the animal kingdom. In this paper, we analyze and synthesize the humpback song using additive synthesis which is one of the most powerful techniques for the analysis, modification, and synthesis of complex audio or speech signals. This method creates complex sounds by adding together individual sinusoidal signals called “partials.” A partial’s frequency and amplitude are each time-varying functions, so it is a more flexible version of the harmonic associated with a Fourier series decomposition of a periodic waveform. Applying the fast Fourier transform to all overlapping frames 共small time segments兲, we can detect peaks from the frequency spectrum of each frame and calculate the frequency, magnitude, and phase for all the peaks. These extracted parameters are then used as components of the sinusoidal signals 共partials兲 for the synthesis process. This process finally reconstructs and concatenates each frame, generating the synthesized humpback song. We observed that this synthesized song resembles much more closely the original humpback song by the time/frequency domain representation and listening. In the future, we will analyze and synthesis other baleen whale songs with this powerful synthesis method. 关Work supported by IITA 共IITA-2008-共C1090-0801-0039兲兲.兴

3aSC12. Geometric dependence of phonation threshold pressure and phonation onset frequency. Zhaoyan Zhang 共UCLA School of Medicine, 31-24 Rehab Ctr., 1000 Veteran Ave., Los Angeles, CA 90095-1794兲 Dependence of phonation threshold pressure and phonation onset frequency on vocal fold geometry was numerically investigated in a continuum model of the vocal folds. The geometric parameters of interest include the medial surface thickness, vocal fold depths of the body, and cover layers. Changes in these parameters may occur either due to laryngeal muscle activation, vocal pathology, or aging. Simulations show that both threshold pressure and onset frequency increased with decreasing vocal fold depth. However, depending on glottal geometry, increasing medial surface thickness may either increase or decrease phonation threshold pressure and frequency. Variation of the medial surface thickness also led to phonation onset occurrence at a different eigenmode, leading to sudden changes in onset frequency and vocal fold vibration pattern. These numerical predictions


PARLOR B/C, 7:45 TO 11:30 A.M. Session 3aSP

Signal Processing in Acoustics and Acoustical Oceanography: Poroelastic Materials: Models, Bounds, and Parameter Estimation Max Deffenbaugh, Chair ExxonMobil Research & Engineering Co., 1545 Route 22 East, Annandale, NJ 08801

Chair’s Introduction—7:45

Invited Papers

7:50 3aSP1. Acoustics in granular porous media and the consolidation continuum. James G. Berryman 共Earth Sci. Div. Lawrence Berkeley Natl. Lab, One Cyclotron, Dr. Berkeley, CA 94720, [email protected]兲 One key influence on acoustic wave propagation in granular porous media is the degree to which the solid constituent grains can be treated as fully consolidated, weakly and/or partially consolidated, or entirely unconsolidated. Well-known results of Gassmann and Biot all implicitly assume that the medium is fully consolidated, with welded contacts at the grain-to-grain interfaces. Such implicit assumptions are also present in standard bounding methods for elastic behavior, such as the Hashin-Shtrikman bounds of elasticity. Influence of reductions in the degree of consolidation can be quantified for partially or weakly consolidated media, and granular media having no welded contacts can also be treated as porous media for sound waves in the Biot-Gassmann sense when grains are experiencing sufficient overall confining stress. Methods recently developed to quantify wave propagation characteristics over the full range of possible behaviors in grain packs, as well as comparisons to experiments, will be presented. 2639




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8:20 3aSP2. Fabric dependence of poroelastic wave propagation. Stephen Cowin and Luis Cardoso 共Dept. of Biomed. Eng., The City College, NY, NY 10031, [email protected]兲 The governing equations for wave motion in the linear theory of anisotropic poroelastic materials are developed and extended to include the dependence of the constitutive relations upon fabric. Fabric is a quantitative stereological measure of the degree of structural anisotropy in the pore architecture of a porous medium. With the addition of the second order symmetric tensor fabric variable, the formulation of wave motions in the poroelastic theory is consistent with the presentations of Biot and later authors. The dependence of all the material tensors in the Biot theory on the fabric tensor aligns the material tensors, so when a single direction that is a plane of material symmetry is selected, the equations simplify considerably. The customary polynomial of the sixth deg for the wave speeds of the anisotropic Biot theory in a selected direction reduces to three quadratic equations to solve for the wave speeds and attenuation. While the theory is applicable to any saturated porous material, the two longitudinal waves predicted by this model are measured in cancellous bone and used to derive the corresponding anisotropic elastic constants. Representative examples of bone loss are analyzed as a function of the porosity, tissue density, and fabric. 8:50 3aSP3. Anisotropic bone loss characterized using fabric-based poroelasticity. Luis Cardoso and Stephen Cowin 共Dept. of Biomedical Eng., The City College, 138th St., and Convent Ave., NY, NY 10031, [email protected]兲 The current gold standard to assess bone loss is the bone mineral density 共BMD兲 test, performed with a dual x-ray absorptiometry system. BMD measurements are highly correlated to bone mass when measured in spine, wrist, and femoral neck. However, the BMD cannot fully explain the decrease in bone strength and the associated risk of fracture because bone loss is not homogeneous, and does not depend on mass changes only. In this study, a fabric-based poroelastic model is used to determine the elastic constants of bone that have undergone disuse-osteoporosis and bone treated with an antiresorptive drug. Images from microCT are used to determine the porosity, density, and fabric on each group of specimens. These measurements are used in the proposed fabric-based poroelastic model to determine the sample’s anisotropic elastic constants. These elastic constants are then compared to the ones obtained by ultrasound wave propagation measurement as previously described in the Cowin and Cardoso presentation. Image analysis and ultrasound wave propagation are both shown able to determine changes in anisotropic elastic constants during bone loss when used with the proposed anisotropic poroelastic model. This study provides the foundation to define a bone quality criterion beyond the sole determination of bone mass.

Contributed Paper In this method, a 3-D image of x-ray attenuation is converted into a 3-D elastic properties volume, the strain field is computed within the volume, and the strain concentration tensors, which quantify the contribution of each grain and pore type to the bulk elastic properties, are calculated from the strain field. From only one representative sample of a rock type and with no assumptions about grain or pore shape, an effective medium model is generated that specifies the effective elastic tensor as a function of the various mineral and pore volume fractions. The method is demonstrated by generating effective medium models for several rock types. These models can be used in hydrocarbon exploration to relate the velocities of seismic waves in a poroelastic reservoir to the porosity, structure, and composition of the rock matrix and the type and distribution of the fluid within the pore spaces.

9:20 3aSP4. Effective medium models from x-ray microtomography images. Max Deffenbaugh, John Dunsmuir 共ExxonMobil Res. and Eng. Co., 1545 Rte. 22 East, Annandale, NJ 08801, [email protected]兲, Shiyu Xu 共ExxonMobil Exploration Co., Houston, TX 77060兲, and Enru Liu 共ExxonMobil Upstream Res. Co., Houston, TX 77252兲 A novel method is described where an effective medium model is generated from a 3-D x-ray microtomography image of a rock sample. In contrast to current modeling practice, material phases are not assigned idealized geometries, like spheroids. Instead, strain concentration tensors are computed numerically for the true phase geometries observed in the 3-D image.

Invited Papers

9:35 3aSP5. Model parameter estimation of a porous seabed using in situ acoustic-probe and chirp-sonar reflection data. Altan Turgut 共Naval Res. Lab., Acoust. Div., Washington, DC 20375兲 The velocity dispersion and frequency dependency of attenuation in marine sediments are two important measures that provide the ability to test the validity of geoacoustic models as well as to estimate physical properties from the acoustic data. A widely-used Biot–Stoll theory for elastic-wave propagation in porous marine sediments seems to predict a narrow band of dispersion that was measured only in well-sorted granular marine sediments 关A. Turgut and T. Yamamoto, J. Acoust. Soc. Am. 87, 2376–2382 共1990兲兴. Recent measurements in silty-sand sediments show almost linear frequency dependency of attenuation and mild velocity dispersion within the 3–80 kHz frequency band. The newly measured attenuation and velocity dispersion curves are in good agreement with those predicted by an extended Biot theory for sediments with a distribution of pore sizes 关T. Yamamoto and A. Turgut, J. Acoust. Soc. Am. 83, 1744–1751 共1988兲兴. Simultaneous measurements of in situ acoustic-probe data and chirp-sonar reflection data are also used to estimate the model parameters of the extended Biot model. 关Work supported by the Office of Naval Research.兴 10:05—10:15 Break

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10:15 3aSP6. Cancellous bone as a poroelastic medium: Extracting underlying material properties from improved ultrasonic measurements of frequency dependent attenuation and phase velocity. James G. Miller, Christian C. Anderson, Adam Q. Bauer, Karen Marutyan, G. Larry Bretthorst, Mark R. Holland 共Washington Univ., 1 Brookings Dr., St. Louis, MO 63130兲, Brent K. Hoffmeister 共Rhodes College, Memphis, TN 38112兲, and Keith A. Wear 共U.S. Food and Drug Administration, Silver Spring, MD 20993兲 Cancellous bone can be modeled as a poroelastic medium consisting of a viscous fluid 共marrow兲 and a stiff framework 共trabeculae兲. Transmission of ultrasound through bone can result in fast and slow waves as well as mode conversion and multiple scattering, all of which can mask the underlying material properties of bone that determine fracture risk. Phase cancellation at the receiving transducer and interference effects in the field can further compromise the potential of bone sonometry for assessing bone quality. The attenuation coefficient is observed to increase approximately linearly with frequency, a fact that accounts for the use of broadband ultrasound attenuation 共BUA兲 to characterize bone. Many laboratories report that the phase velocity of ultrasonic waves propagating through cancellous bone decreases with increasing frequency 共negative dispersion兲. However, an increase in phase velocity with frequency 共positive dispersion兲 would be expected based on the causality-imposed Kramers–Kronig relations. This apparent negative dispersion in bone can arise from interference between fast wave and slow wave longitudinal modes. Interference and phase cancellation at the receiver can also be sources of artifactual alterations in the attenuation and phase velocity. 关Work supported in part by NIH R37HL40302 R01AR057433, NSF CBET-0717830兴.

Contributed Papers 10:45 3aSP7. Successful use of Bayesian inference to obtain the fast and slow wave properties of cancellous bone from sonometry measurements. Christian C. Anderson 共Washington Univ., 1 Brookings Dr., St. Louis, MO 63130兲, Michal Pakula, Pascal Laugier 共Univ. Paris 6, 75006 Paris, France兲, Adam Q. Bauer, Karen Marutyan, G. Larry Bretthorst, Mark R. Holland, and James G. Miller 共Washington Univ., St. Louis, MO 63130兲 Clinical trials have demonstrated that frequency dependent attenuation 关broadband ultrasound attenuation, 共BUA兲兴 and speed of sound 共SOS兲 provide an assessment of fracture risk. Previous studies from our laboratory of the “forward problem” show that the negative dispersion observed in cancellous bone can arise when signals consisting of overlapped fast and slow waves are analyzed as if only one wave is present. The present study examines the “inverse problem” using Bayesian probability methods suitable for recovering the underlying material properties from received transmission sonometry signals complicated by the presence of multiple signals. Transmission studies were carried out on bone mimicking phantoms and on specimens of femur condyles. Received rf signals served as input to our Bayesian algorithm. The program that implements the Bayesian calculations reconstructs the individual fast and slow waves and constructs the model output from parameters that maximize the joint posterior probability. Composite rf signals constructed by summing these waves were in excellent agreement with signals transmitted through bone-mimicking phantoms and were in good agreement with signals transmitted through bone samples despite the additional complexities arising from ultrasound propagation through the complex trabecular network. 关Work supported in part by NIH R37HL40302 R01AR057433, and NSF CBET-0717830兴. 11:00 3aSP8. Geoacoustic inversion performed from two source-receive arrays in shallow-water waveguide. Alexey Sukhovich, Philippe Roux, and Marc Wathelet 共LGIT, UMR CNRS 5559, Univ. Joseph Fourier, Grenoble, France, [email protected]兲 Raylike propagation of acoustic waves in a shallow-water waveguide between two vertical line arrays is investigated by applying a double beam-

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forming algorithm, which performs time-delay beamforming on both emitting and receiving arrays and allows identification of eigenrays by their emission and reception angles and arrival times. From the intensity of each eigenray, it is possible to determine reflection coefficient from the bottom of the waveguide as a function of an angle of incidence. The procedure was initially tested in a small-scale tank experiment for an acoustic waveguide with either steel or Plexiglas bottom. By fitting an experimentally found reflection coefficient with a corresponding theoretical expression, an estimate for the speed of shear waves in the bottom material was obtained. Similar analysis was subsequently applied to the data obtained during an at-sea experiment, which was performed between two vertical transducer arrays in shallow-coastal waters of the Mediterranean. An angle-dependent bottom reflection coefficient was extracted and geoacoustic inversion was performed by fitting the data with theoretical calculations, in which bottom sediments were modeled as a multilayered system. Good agreement between experiment and theory was observed. Our results indicate possible application of eigenray intensity analysis based on double beamforming algorithm for geoacoustic inversion problems. 11:15 3aSP9. Monitoring stress related velocity variation in concrete with a 2ⴛ10ⴚ5 relative resolution using diffuse ultrasound. Larose Eric 共Lab. de Geophys. interne et Tectonophysique, CNRS & Univ. J. Fourier, Grenoble, France兲 and Hall Stephen 共CNRS & Grenoble Univ., Grenoble, France兲 Ultrasonic waves propagating in solids have stress-dependent velocities. The relation between stress 共or strain兲 and velocity forms the basis of nonlinear acoustics. In homogeneous solids, conventional time-of-flight techniques have measured this dependence with spectacular precision. In heterogeneous media such as concrete, the direct 共ballistic兲 wave around 500 kHz is strongly attenuated and conventional techniques are less efficient. In this manuscript, the effect of weak stress changes on the late arrivals constituting the acoustic diffuse coda is tracked. A resolution of 2⫻10⫺5 in relative velocity change for stress change is attained. We are thus sensitive to stress change much lower than 50 kPa. This provides an original way to measure the nonlinear parameter with relatively small stress variations 共less than 100 kPa兲.



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PAVILION WEST, 8:00 TO 11:55 A.M. Session 3aUW

Underwater Acoustics and Acoustical Oceanography: Physics-Based Undersea Clutter Model Verification and Validation I Juan I. Arvelo, Cochair Applied Physics Lab., Johns Hopkins Univ., Laurel, MD 20723-6099 Kenneth G. Foote, Cochair Woods Hole Oceanographic Inst., Woods Hole, MA 02543 Timothy K. Stanton, Cochair Dept. of Applied Ocean Physics and Engineering, Woods Hole Oceanographic Inst., Woods Hole, MA 02543 Chair’s Introduction—8:00

Invited Paper 8:05 3aUW1. Dynamic and acoustic modeling of discrete biologics for active sonar simulation. Brian R. La Cour and John E. Hamann 共Appl. Res. Labs., The Univ. of Texas at Austin, P.O. Box 8029, Austin, TX 78713-8029兲 A model is proposed for simulating the group dynamics and acoustic echoes of aggregate, discrete biologics in midfrequency 共2–5 kHz兲 active undersea sonar. Using a Lagrangian description, group behavior is modeled by a set of Newtonian forces and stochastic perturbations on a collection of point masses. Interactions comprise a grouping force, which gives a characteristic separation distance, and an arrayal force, which tends to align the velocities of the group’s constituents. The group dynamics is characterized in terms of their statistical and asymptotic properties and studied as a function of the model parameters. Several models for the acoustic response are considered and studied for both individual and aggregate response. Finally, the resulting synthetic echoes are compared against those of actual biologics measured on a midfrequency active sonar system. The synthetic echoes are found to reproduce well both the qualitative characteristics of measured biologics and the resulting tracking and classification features found in a typical active sonar signal and information processing chain.

Contributed Paper 8:25 3aUW2. Coherent backscattering effect from mid-frequency reverberation measurements in shallow-water. Karim G. Sabra 共School of Mech. Eng., Georgia Inst. of Technol., 771 Ferst Dr. NW, Atlanta, GA 30332-0405兲

with respect to any other direction. We will present experimental observations of the coherent backscattering effect from mid-frequency reverberation data 共3–4 kHz兲 collected in shallow water off the west coast of Italy using various sensor array configurations. This demonstrates the presence of coherent effects in shallow water reverberation recordings from rough seabeds. Hence, coherent reverberation effects need to be accounted for to obtain accurate predictions of sea clutter levels. Furthermore, accurate rendering of the coherent backscattering effect could be used to simply verify and validate physics-based undersea clutter models. Practical implementation for the design of active sonar systems will be discussed. 关Work supported by ONR, Code 321.兴

The coherent backscattering 共or backscattering enhancement兲 effect is a persistent interference effect which occurs between waves propagating in random media such as randomly distributed scatterers and rough surfaces. Previous experimental and theoretical studies in optics, acoustics, or seismology have demonstrated that the coherent backscattering results in a doubling of the recorded intensity reflected exactly in the backward direction

Invited Papers

8:40 3aUW3. Measurements and modeling of midfrequency clutter from fish aggregations over Georges Bank in the Gulf of Maine. Roger C. Gauss, Joseph M. Fialkowski, Richard Menis, Edward L. Kunz 共Naval Res. Lab., Code 7140, Washington DC 20375-5350, [email protected]兲, Timothy K. Stanton, Cynthia J. Sellers 共Woods Hole Ocean. Inst., Woods Hole, MA 02543兲, and J. Michael Jech 共NOAA NE Fish. Sci. Ctr., Woods Hole, MA 02543兲 Broadband midfrequency acoustic measurements of fish backscattering were made with two complementary sonar systems in September 2008 at the northern slopes of Georges Bank in the Gulf of Maine. One system, towed near the surface, was downward-looking 共short-range: ⬍ 0.2 km兲 and was used to image fish at high vertical resolution throughout the water column. The other system was horizontal-looking 共relatively long-range: 1–10 km兲, consisting of a vertical source array and a horizontal receive array, and was used to image fish at high horizontal resolution. In this talk, the focus is on characterizing the longer-range data. Spectrogram analysis showed that the echoes had resonance frequencies in the 2–4 kHz band, consistent with scattering by Atlantic herring, while examination of normalized match-filter output revealed strong, spatiotemporally variable clutter. The associated probability-density functions 2642




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共PDFs兲 exhibited variable non-Rayleigh behavior. Several PDF models were fit to the data, with the K and Poisson-Rayleigh PDF models providing not only good fits, but physical insights into the clutter process 共such as estimates of the expected number of discrete scatterers per unit area兲. These results provide an improved understanding of both fish behavior and the characteristics of fish aggregations as long-range clutter fields. 关Work supported by ONR.兴 9:00 3aUW4. Bioalpha, transmission loss and validation of scattering models in biologically intense shallow water environments. Orest Diachok 共Appl. Phys. Lab. Johns Hopkins Univ., Laurel, MD 20723-6099兲 Scattering and extinction by fish swim bladders are manifestations of the same phenomenon. Scattering causes reverberation from dispersed fish and distinct echoes from fish schools 共clutter兲, and diminishes the magnitude of transmitted signals. The biological extinction coefficient 共bioalpha兲 has been shown to have a large effect on transmission loss 共TL兲 in several biologically intense, shallow water environments, including the Bristol Channel 关Weston 共1967兲兴, Yellow Sea 关Qiu et al. 共1999兲兴, Gulf of Lion 关Diachok 共1999兲兴, and Santa Barbara Channel 关Diachok 共2005兲兴. Consequently, models of biological scattering must include the effects of bioalpha on TL in shallow water environments. The objectives of this paper are to review the experimental evidence of the effects of bioalpha on TL, and to describe and demonstrate the effectiveness of an analytical approach to modeling this phenomenon. Since it is not possible at present to predict the effects of bioalpha on TL from first principles 共distributions of swim bladder dimensions, spatial distributions of number densities, and timing of diurnal changes in school structures and seasonal migration patterns are only approximately predictable兲, experiments designed to demonstrate the validity of scattering models in biologically intense, shallow water environments should include concurrent broadband TL measurements during both night and day.

Contributed Paper Ehrenberg 关Proc. Conf. Eng. Ocean Environ. 1, 61–64, 共1972兲兴 and Barakat 关Optica Acta 21, 903–921, 共1974兲兴 is developed to account for a directional sonar beam involving an arbitrary finite number of scatterers, each with an arbitrary echo probably density function 共PDF兲 and randomly located in the beam. Theoretical predictions are made, along with numerical simulations for validation, for a range of conditions, including: 共1兲 different number of scatterers arbitrarily located in the beam and 共2兲 different echo PDFs of the scatterers. Here, a “scatterer” could be an individual or a patch of scatterers whose dimensions are much smaller than the footprint of the sonar beam. Although the application is intended for volumetric patches, the formulation could be applied to areal patches under appropriate conditions. 关Work supported by ONR.兴

9:20 3aUW5. Statistics of echoes from a directional sonar beam insonifying finite numbers of single scatterers and patches of scatterers. Dezhang Chu 共NOAA/NMFS/Northwest Fisheries Sci. Ctr., Seattle, WA 98112兲 and Timothy K. Stanton 共Woods Hole Oceanograph. Inst., Woods Hole, MA 02543兲 When a sonar beam sweeps across a field of scatterers, the echoes can fluctuate significantly from ping to ping. The fluctuations can be strongly non-Rayleigh because: 共1兲 there can be a small number of scatterers in the beam; 共2兲 the distribution of scatterers can be inhomogeneous or “patchy;” and 共3兲 the echoes are weighted by the nonuniform response of the sonar beam. In this paper, a general formulation combining equations derived by

Invited Papers 9:35 3aUW6. Comprehensive, integrated database of elements contributing to bottom and volume clutter. Kathleen J. Vigness-Raposa, William T. Ellison, Adam S. Frankel, David Zeddies, Cheryl L. Schroeder 共Marine Acoust., Inc., 809 Aquidneck Ave., Middletown, RI 02842, [email protected]兲, Peter V. August, Christopher Damon, and Charles LaBash 共Univ. of Rhode Island, Kingston, RI 02881兲 Multiple components within and at the bottom of the water column can scatter acoustic signals, resulting in decreased sonar performance and compromised tactical decision making. Many of the biological organisms that contribute to acoustic clutter are also protected or managed species, integral to a fully functional marine ecosystem. In order to understand, predict, and model bottom and volume scattering, detailed descriptions of the spatial, spectral, and temporal variability of clutter elements are needed, along with reliable estimates of backscattering strength. All of these necessary components are dependent on marine wildlife databases. Efforts by several organizations have resulted in databases that provide pieces of the overall puzzle. Databases of distribution and abundance 共Census of Marine Life’s OBIS-SEAMAP兲, two-dimensional movement 共Census of Marine Life’s Tagging of Pacific Pelagics兲, and diving and movement behavior 共Marine Wildlife Behavior Database兲 are examples of current, but disparate, projects. Ongoing efforts are consolidating inputs from such databases to predict realistic, spatially dependent bioclutter animats. By linking geospatial features of clutter elements in training and mission planning systems, sonar operators and designers can better predict and analyze the occurrence of target-like clutter. 关Work supported by NAVSEA SBIR, ONR STTR, and NOAA.兴 9:55—10:15 Break

10:15 3aUW7. Modeling persistent clutter. Bruce K. Newhall 共Johns Hopkins Univ., Appl. Phys. Lab, 11100 Johns Hopkins Rd., Laurel, MD 20723兲 Clutter is the collection of targetlike returns from nontarget sources that are observed in active sonar use. Persistent clutter is the set of clutter returns that persist across multiple transmissions and thereby form false target tracks in sonar processing. The U.S. Navy is developing active sonar simulators for training purposes. Effective training requires physically realistic clutter simulation including modeling of persistent clutter. Potential physical sources of persistent clutter are discussed, and a variety of modeling approaches are reviewed. Measures of effectiveness for model comparison with persistent clutter data are given. 2643




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10:35 3aUW8. Exploring spatiotemporal distribution as a clutter simulation validation measure. Juan I. Arvelo, Jr. 共The Johns Hopkins Univ., Appl. Phys. Lab., 11100 Johns Hopkins Rd., Laurel, MD 20723-6099兲 The amplitude distribution is widely used to compare modeled and measured undersea clutter 关J. Arvelo et al., JASA 120, 3381 共2006兲兴. However, additional validation measures must be identified to ensure that clutter models are suited to realistically simulate active sonar displays and accurately emulate tracker performance. For example, the amplitude distribution ignores the stochastic arrangement of clutter at various space/time scales 关V. Lupien, JASA 105, 2187–2282 共1999兲兴. Active midfrequency vertical line array data from the ASIAEX 2001 experiment in the East China Sea is processed to explore the suitability of the clutter spatiotemporal distribution as a key validation measure. The vertical array permitted the separation of bottom from surface generated clutter. A physicsbased seafloor clutter model 关B. Newhall and J. Arvelo, JASA 118, 2041 共2005兲兴 was implemented to simulate the experimental scenario with known measured and inferred environmental conditions. Comparisons of the measured and simulated amplitude and spatiotemporal distributions uncovered significant effects that must be included to improve existing clutter models. 关This effort was conducted under the auspices of the Undersea Warfare Business Area Independent Research and Development program of the Johns Hopkins University Applied Physics Laboratory.兴

10:55 3aUW9. Midfrequency active sonar clutter statistics segregated by broad clutter types. James M. Gelb 共Appl. Res. Labs., UT Austin, 10000 Burnet Rd., Austin, TX 78758, [email protected]兲 The empirical distributions of normalized matched-filter echoes from a midfrequency active sonar with hyperbolic frequencymodulated waveforms in a myriad of oceanic environments are studied for three broad clutter classes: bottom structures, diffuse compact clutter 共e.g., seaweed兲, and compact nonstationary clutter 共e.g., biologics兲. The distributions are characterized using the K distribution and the generalized Pareto distribution. Methods of parameter estimation are discussed, and parameters are computed for small subregions of the clutter fields. A plot of the Kolmogorov–Smirnov goodness-of-fit statistic of individual subregions is presented for each model and class to highlight the versatility of the models when applied to large quantities of data. Cumulants are computed from the data and are utilized as features in a classifier to demonstrate separability between the classes. An important aspect of this work is the use of distinct clutter classes as opposed to collectively characterizing all clutter as reverberation. Environmental effects are not considered, as the goal of this work is to determine the utility of local clutter estimation models in practical sonar processing systems where accurate environmental data is unavailable. 关This work is sponsored by the Office of Naval Research undersea signal processing discovery and invention program.兴

11:15 3aUW10. Simulation of rippled-sand sonar imagery with visual and statistical verification. Shawn F. Johnson 共Graduate Prog. in Acoust., Appl. Res. Lab., 117 Appl. Sci. Bldg., State College, PA 16804兲 Synthetic aperture sonar 共SAS兲 imagery is often characterized by a decidedly non-Rayleigh pixel amplitude distribution, owing to its inherent high-resolution combined with speckle induced by the coherent image formation process. Recent work has shown increasing the resolution cell size by limiting the image bandwidth typically produces images with statistics tending toward a Rayleigh distribution. A caveat to this generalization is that the trend toward Rayleigh is dependent on orientation of the SAS system to strongly correlated sea-floor structures such as sand-ripples. A method has been developed to simulate rippled-sand sonar imagery at high-frequencies 共i.e., on the order of 100 kHz兲, which accounts for nonsymmetric ripple shape, sediment acoustic properties, sonar to ripple orientation, system resolution, and coherent imaging induced speckle. This numerical simulation method is computationally inexpensive and compares well both visually and statistically with collected data over a wide range of orientation angles. Simulation methods will be presented with verification using SAS imagery collected by the Naval Surface Warfare Center: Panama City Division. 关Work supported by ONR Grants No. N00014-04-1-0013 and No. N00014-06-1-0245, and Code 32.兴

11:35 3aUW11. Experimental tests of models for high-frequency scattered envelope statistics. Anthony Lyons 共Appl. Res. Lab., Penn State Univ., State College, PA 16804, [email protected]兲 There has been, in general, a lack of quantitative comparison between high-frequency physics-based clutter model predictions and experimental data due mainly to difficulties in performing well-controlled at-sea experiments and obtaining necessary ground truth. To address this shortfall, experiments have been performed over the past 5 yrs to gather data with which to confront recently developed physics-based clutter models. The experimental data sets were obtained during experiments conducted off of Elba Island, Italy in May 2003 and at Seneca Lake, New York, in the summers of 2005 and 2006. Colocated high-frequency, broadband acoustic data and highresolution environmental ground truth data were collected as part of these experiments. In all cases comparisons between model predictions and measured data showed promising similarities in K-distribution shape parameter estimates and their dependence on bandwidth, grazing angle, and seafloor type. The favorable model/data comparisons show that it is possible to link the scattered envelope distribution to measurable environmental properties, providing the foundation necessary for solving several important problems related to the detection of targets in non-Rayleigh clutter including performance prediction for different systems based on seafloor properties and extrapolation of performance to other systems and bandwidths.

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WEDNESDAY AFTERNOON, 20 MAY 2009

COUNCIL SUITE, 1:00 TO 2:00 P.M. Session 3pAAa

Architectural Acoustics: Absorption Testing and Characterization Ron Sauro, Chair NWAA Laboratories Inc., 25132 Rye Canyon Loop, Santa Clarita, CA 91355 Contributed Papers 1:00 3pAAa1. Impedance tube absorption testing of poly blend materials presently used in the carpet industry. Ruth Anne Mazur 共Columbia College Chicago, 237 E. Wildflower Ln., Round Lake Beach, IL 60073, ruthie [email protected]兲 Cyril M. Harris authored a paper in 1955 titled “Acoustical Properties of Carpet” in which absorption coefficients for carpet were examined according to specific parameters, including fiber content. Since then, new fibers and blends have been introduced into the carpet industry. This study aims to compare absorption coefficients found from testing of these newer fibers. New blends that are now commonly used and sold in the carpet industry include polyester, polypropylene, and polyurethane. Using a Bruel & Kjaer Two Microphone Impedance Measurement Tube and Bruel & Kjaer PULSE LabShop, normal incidence absorption coefficients are gathered in order to compare the coefficient curves for these materials. Testing is performed in accordance with the ASTM E 1050-98 standard. Preliminary testing on carpet with these fibers shows lower values from 3.5 to 6.5 kHz in the curves for polypropylene carpet with padding compared to other fibers with padding. Several parameters of the preliminary samples were not constant and may have affected the results. Ongoing analysis and testing of newer fibers will enable comparison with previous studies. Absorption coefficients and parameters for carpet available in acoustical modeling programs will also be assessed in relation to the results. 关Work supported by Columbia College Chicago.兴 1:15 3pAAa2. Felt panels for an art space. Jessamyn A. Newcomb 共Dept. of Architecture, Virginia Polytechnic and State Univ., 201 Cowgill Hall 共0205兲, Blacksburg, VA 24061兲 The art building on Virginia Tech’s campus is an adaptive reuse project. Despite its current function, the transformation of the space has left it acoustically ill suited for class instruction. This research focuses on absorption of specific frequencies through the use of felt panels to reduce noise and in-

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crease speech intelligibility for class instruction. Microperforated panels are proposed as a solution due to their simple structures and predictable wideband absorption characteristics. Benefits will be quantified by measuring pink noise decay in the building pre- and postpanel installation. 1:30 3pAAa3. Absorption coefficients part 1: Is square area enough? Ron Sauro, Michael Vargas 共NWAA Labs., Inc., 25132 Rye Canyon Loop, Santa Clarita, CA 91355, audioគ[email protected]兲, and Gary Mange 共Western Electroacoustics Labs., Santa Clarita, CA 91355兲 Attempting to correlate the measurements of absorption coefficients in ASTM-C423, ISO-354, and ISO-17497-1, it was observed that the results were varying to a large degree. An experiment was set up with 1 in., 6 lb density fiberglass panels having different shapes, sizes, and parameters. The shapes, sizes, and parameters of the panels are described in this paper. The types of experiments are also described along with the process that was used based on input from many of the members of the industry. The end results and conclusions are described in a paper titled “Absorption coefficients part 2: Is “edge effect” more important than expected?” 1:45 3pAAa4. Absorption coefficients part 2: Is “edge effect” more important than expected? Ron Sauro, Michael Vargas 共NWAA Labs., Inc., 25132 Rye Canyon Loop, Santa Clarita, CA 91355, [email protected]兲, and Gary Mange 共Western Electro-Acoust. Labs., Santa Clarita, CA 91355兲 Attempting to correlate the measurements of absorption coefficients in ASTM-C423, ISO-354, and ISO-17497-1, it was observed that the results were varying to a large degree. An experiment was set up as described in a paper titled “Absorption coefficients part I: Is square area enough?” It was observed that the edges of the sample had a significant effect on the absorption coefficient. The results of these experiments are presented in numerical and graphic form in this paper along with conclusions and suggested corrections to the “absorption coefficient” as used in all calculations in acoustics.



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FORUM SUITE, 1:00 TO 3:25 P.M. Session 3pAAb

Architectural Acoustics: American Institute of Architects Short Course K. Anthony Hoover, Chair McKay Conant Hoover, Inc, 5655 Lindero Canyon Rd., Suite 325, Westlake Village, CA 91362 Chair’s Introduction—1:00

Invited Papers 1:05 3pAAb1. Introduction to workshop goals. K. Anthony Hoover 共McKay Conant Hoover, Inc., 5655 Lindero Canyon Rd., Westlake Village, CA 91362兲 and Bennett M. Brooks 共Brooks Acoust. Corp., Vernon, CT 06066兲 Many states require that architects obtain continuing education unit 共CEU兲 credits annually, in order to maintain their registration or licensure. The American Institute of Architects 共AIA兲 Continuing Education System 共CES兲 offers continuing education courses, which may be given by third party providers. The Technical Committee on Architectural Acoustics 共TCAA兲 is an AIA/CES Registered Provider. The goal of this workshop is to prepare members of the TCAA so that they may be authorized to present a short course which can earn attendees CEU credit. In order for TCAA members to qualify to meet the AIA requirements, they must attend this workshop, which is given in two parts. The first part will be devoted to the short course presentation material, which is in a standardized format. The second part of the workshop will focus on the AIA CEU Program registration and reporting requirements. Of course, anyone is free to register with the AIA to provide their own CEU program. However, the advantages of participating in this program are that the TCAA short course is already prepared, is preapproved by the AIA, and the registration fees are paid by the Acoustical Society of America. 1:25 3pAAb2. Architectural acoustics: Short course presentation material. K. Anthony Hoover 共McKay Conant Hoover, Inc., 5655 Lindero Canyon Rd., Westlake Village, CA 91362兲 The Technical Committee on Architectural Acoustics 共TCAA兲 is a Registered Provider in the American Institute of Architects 共AIA兲 Continuing Education System 共CES兲. The TCAA has developed a standardized introductory short course for architects, called “Architectural Acoustics.” An architect can earn one continuing education unit 共CEU兲 by attending this short course, if it is presented by a qualified member of TCAA. The course covers topics in sound isolation, mechanical system noise control, and finish treatments. This paper will cover the course material in order to prepare and qualify potential presenters. There will be time at the end of the paper for questions and answers on the course material. In order to qualify as an authorized presenter for this AIA/CES short course, attendance at this workshop and membership in TCAA are required. 2:25 3pAAb3. Provider registration and reporting requirements. Bennett Brooks 共Brooks Acoust. Corp., 30 Lafayette Sq., Ste. 103, Vernon, CT 06066兲 The Technical Committee on Architectural Acoustics 共TCAA兲 is a Registered Provider in the American Institute of Architects 共AIA兲 Continuing Education System 共CES兲. The TCAA has developed a standardized introductory short course for architects. The TCAA short course is called “Architectural Acoustics” and attendance at this 1-hour-long course can earn an architect one continuing education unit 共CEU兲. This paper will cover the administrative requirements of the AIA/CES, to prepare potential presenters. These requirements include the proper handling of paperwork, so that AIA members may receive credit for the course. Also, the manner in which the course is given is dictated by AIA requirements. TCAA membership and attendance at this workshop are required to qualify as an authorized presenter for this AIA/CES short course.

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BROADWAY I/II, 1:00 TO 2:05 P.M. Session 3pAB

Animal Bioacoustics and Acoustical Oceanography: Autonomous Remote Monitoring Systems for Marine Animals IV Catherine L. Berchok, Chair National Marine Mammal Lab., Alaska Fisheries Science Ctr./NOAA, Seattle, WA 98115-6349 Invited Paper 1:00 3pAB1. Call localization of marine mammals using directional autonomous recorders. Susanna B. Blackwell, Charles R. Greene, Jr. 共Greeneridge Sci., Inc., 1411 Firestone Rd., Goleta, CA 93117, [email protected]兲, Christopher S. Nations, Trent L. McDonald 共WEST, Inc., Cheyenne, WY 82001兲, Aaron Thode 共Univ. of California, San Diego, La Jolla, CA 92037兲, and A. Michael Macrander 共Shell Exploration and Production Co., Anchorage, AK 99503兲 Directional sensors of low-frequency acoustic waves have been used by navies in sonobuoys for submarine detection and localization for decades. Composed of an omnidirectional pressure sensor and two horizontal directional elements sensitive to particle motion, they provide information for determining the relative bearing to a sound source without ambiguity. They were adapted for bowhead whale monitoring in the mid-1980s and have been used in autonomous seafloor acoustic recorders since 2000. Applied to the coastal Beaufort Sea north of Alaska, fall bowhead migration was observed in detail during 2007 and 2008, providing a wealth of information on variability in the migration paths of calling whales and the influence of industrial sounds on the locations of calling whales. For example, many calls were detected within about 30 km of seismic survey activities, where received sound pressure levels from airgun pulses were often greater than 140 dB per 1 µPa. Also, seismic activities were correlated with statistically significant shifts in the whales’ distance from shore, either offshore or inshore. However, interpretation of the results was challenged by the difficulty in distinguishing between a whale that ceases calling and a whale that deflects away from the study area. 关Work supported by Shell Oil Co.兴

Contributed Papers 1:20 3pAB2. Killer whale habitat use and prey fields from remote hydrophones and echosounders. Scott Veirs 共Beam Reach Marine Sci. and Sustainability School, 7044 17th Ave NE, Seattle, WA 98115, [email protected]兲, Val Veirs 共Colorado College, Colorado Springs, CO 80903兲, Jason Wood 共The Whale Museum, Friday Harbor, WA 98250兲, Brian Moore, Bob McClure 共BioSonics, Inc., Seattle, WA 98107兲, and Bob Otis 共Ripon College, Ripon, WI 54971兲 The Salish Sea Hydrophone Network has been providing live audio streams to listeners around the globe for the past three years. Five hydrophones around the core summer habitat of the endangered southern resident killer whales allow detection of killer whale presence and inference of pod identity based on call associations. Detection of calls, whistles, and clicks is accomplished automatically by spectral and time domain analysis and manually by a global network of trained human listeners. The hydrophone network is more effective than a sighting network for detecting killer whales during inclement weather and at night, and for generating real-time notifications to alert researchers and managers. Additionally, the live streams and archived recordings have enriched educational activities of local museums and aquariums. In 2008, the hydrophone at Lime Kiln State Park was supplemented by hydroacoustic surveys conducted using a Biosonics echosounder 共200 kHz兲. From August through December the echosounder was deployed at 15 m depth to conduct a continuous, fixed, horizontal survey. Remote display technology was used to monitor the echosounder in real time while also listening to the live audio stream. The resultant time series of fish density and acoustic behavior of killer whales is presented.

1:35 3pAB3. Detecting humpback whale sounds in the Bering Sea: Confounding sounds in a cacophony of noise. Sara L. Heimlich, David K. Mellinger, Sharon L. Nieukirk, Holger Klinck 共Cooperative Inst. for Marine Resour. Stud., Hatfield Marine Sci. Ctr., Oregon State Univ., 2030 S. Marine Sci. Dr., Newport, OR 97365兲, Kate Stafford, Sue E. Moore, and Phyllis J. Stabeno 共Univ. of Washington, Seattle, WA 98105兲 2647


Humpback whales 共Megaptera novaeangliae兲 are top predators of large zooplankton and forage fish, and one of the most common large whales in the Bering Sea. While present on feeding grounds, humpback whales produce nonsong sounds probably associated with feeding or social contacts. However, little is known about these highly variable sounds, and their detection is challenging. Recordings were collected during 2006–2007 at the long-term oceanographic moorings M2, M4, and M5 in the eastern Bering Sea. Passive acoustic detection of humpback whale calls in these recordings was confounded by a variety of other sounds, which fall within the same parameters as nonsong humpback vocalizations. An automatic algorithm that detects tonal sounds in the 300–950 Hz frequency band was used to find humpback calls. Raw detections were visually examined to verify the accuracy of the detections. This algorithm resulted in a significant number of wrong detections 共false positives兲, especially sounds of bearded seals 共Erignathus barbatus兲 and bowhead whales 共Balaena mysticetus兲. An error rate was calculated to correct the high number of false detections, and further refinements were made to the automatic detection algorithm. The problems and possible solutions to detecting humpback whale sounds in complex acoustic recordings will be presented.

1:50 3pAB4. Monitoring cetaceans on seamounts in the Azores using passive acoustic techniques. Irma Cascäo 共Inst. of Marine Res., Dept. of Oceanogr. and Fisheries, Univ. of the Azores, Horta, Portugal, [email protected]兲, Marc O. Lammers 共Univ. of Hawaii, Kailua, HI 96734兲, Monica A. Silva, Pedro Afonso, Rui Prieto, and Ricardo S. Santos 共Univ. of the Azores, Horta, Portugal兲 Seamounts are hotspots of marine life in the Azores, acting as feeding stations for diverse top predators, including cetaceans. Long-term monitoring of remote marine ecosystems is logistically difficult and expensive, involving high costs in terms of ship time and human resources, as well as being reliant on sea conditions. Passive acoustic methods are a highly efficient monitoring technique to study the distribution or abundance of 157th Meeting: Acoustical Society of America


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vocalizing cetacean species. In 2007, we began to deploy Ecological Acoustic Recorders 共EARs兲—two shallow 共35 m兲 and two deep 共190 m兲 units—around seamounts to explore and monitor the occurrence of cetaceans, their temporal patterns, and changing levels of activity. A wide variety of time series acoustic signals were collected, revealing the presence of different species of cetaceans and specific associations between species,

based on their vocalization characteristics. Detections of vessels are being used to determine levels of activity at one of the study sites, Formigas bank marine reserve, making the EAR a useful tool to monitor protected areas. The EARs are an effective ecological instrument for monitoring cetaceans year-round and will provide a better understanding of the influence of seamounts on cetaceans’ behavior.


PAVILION WEST, 2:15 TO 3:15 P.M. Session 3pAO

Acoustical Oceanography: Acoustical Oceanography Prize Lecture Jeffrey A. Nystuen, Chair Applied Physics Lab., Univ. of Washington, Seattle, WA 98105-6698 Chair’s Introduction—2:15

Invited Paper 2:20 3pAO1. Seabed characterization and model based processing: Past, present, and future. Martin Siderius 共Dept. of Elect. and Comput. Eng., Portland State Univ., 1900 SW 4th Ave., Portland, OR 97201, [email protected]兲 One of the most active areas of research in acoustical oceanography has been the study of seabed acoustics. This has been partly motivated by the need for accurate sonar performance prediction, which often depends on knowledge of the seabed properties. There has also been significant research on environmentally adaptive and model based signal processing such as matched field processing. One of the obstacles to model based processing has been the required knowledge about seabed properties, which is needed as input. This dependency, in part, led to the innovation of matched field inversion methods to obtain seabed properties. In recent years, new algorithms have been introduced that use ambient noise 共e.g., from breaking waves兲 as a surrogate sound source to probe the seabed and estimate geoacoustic properties. These noise methods have received much attention since measurements and processing are simple and the results are surprisingly good. In fact, current developments in noise processing may be the key to enabling model based methods that, in the past, were not considered practical. In this presentation a review of seabed inversion methods will be given with discussion about current developments in noise processing and the potential for renewed interest in model based processing.

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PAVILION EAST, 12:45 TO 3:15 P.M. Session 3pBB

Biomedical Ultrasound/Bioresponse to Vibration and Physical Acoustics: Shock Wave Therapy II Michael R. Bailey, Cochair Applied Physics Lab., Univ. of Washington, Seattle, WA 98105 Thomas J. Matula, Cochair Applied Physics Lab., Univ. of Washington, Seattle, WA 98105 Contributed Paper 12:45 3pBB1. Interaction of single biological cell with tandem microbubbles in microfluidics. Georgy Sankin, Fang Yuan, and Pei Zhong 共Dept. of Mech. Eng. Mat. Sci., Duke Univ., 144 Hudson Hall, Durham, NC 27708, gns @duke.edu兲

using high-speed video cameras and µPIV technique. Two liquid microjets moving in opposite directions can be generated when the second bubble is produced at the maximum size of the first one. The interaction of these tandem microbubbles with single cell leads to controllable poration of adjacent cell membrane and dye uptake. µPIV data are compared with cell viability at various bubble-cell distances and azimuthal orientations. This method provides a new approach for highly selective cell treatment in situ, applicable to targeted microinjection of macromolecules and gene vectors in microfluidics devices. 关Work supported in part by NIH.兴

Coupled oscillation of two laser generated microbubbles 共maximum radius ⫽ 28 µm兲 and associated shear stresses are investigated experimentally. Bubble-bubble interaction in a microchannel of 25 µm height is observed

Invited Papers

1:00 3pBB2. Treating heterotopic ossification with shockwaves. Michael W. Chang 共12340 NE 8th St., Ste. 101, Bellevue, WA 98005兲, Thanaphum Osathanon, and Cecilia Giachelli 共Univ. of Washington, Seattle, WA 98195兲 Heterotopic ossification 共HO兲 is formation of lamellar bone in soft tissue, commonly seen among patients with burns, orthopedic fractures/procedures, brain/spinal cord injuries, muscle contusions, and rare hereditary disorders. Patients with HO experience pain and joint limitations, which further exacerbate their disability. Reduction of HO preventatively and/or for treatment has been attempted using medications, radiation, and surgery with limited success. Recent encouraging clinical HO outcomes using shockwave therapy have been discussed but treatment mechanisms were unclear. Mechanisms such as spallation, cavitation, squeezing, superfocusing, fatigue, and layer separation have been proposed for lithotripsy. Mineralized calcium phosphate macroporous nanofibrous fibrin scaffolds were used as a HO model to study treatment mechanisms. The HO was treated with electrohydraulic shockwave devices. The scaffold calcium contents decreased from 45.4共3.6兲共untreated兲 to 20.9共18.1兲共OssaTron, 0.71 mJ/mm2兲 and 27.5共23.5兲 ugCa/mg dry weight 共EvoTron, 0.46 mJ/mm2兲 with 200 shocks 共1 Hz兲. Scanning EM of the shockwave-treated HO supports separation of the calcium phosphate from the fibrin matrix probably contributed by shear and cavitation. Biological responses to shockwaves, such as inflammation, neovascularization, angiogenesis may also play important roles in clinical HO treatment. A unique clinical HO case is discussed to illustrate risks, benefits, and challenges from shockwave therapy.

1:15 3pBB3. Histotrispy: Urologic applications. William W. Roberts, Timothy L. Hall, Christopher R. Hempel 共Dept. of Urology, Univ. of Michigan, TC 3879, 1500 East Med. Ctr. Dr., Ann Arbor, MI 48109-5330, [email protected]兲, Zhen Xu, J. Brian Fowlkes, and Charles A. Cain 共Univ. of Michigan, Ann Arbor, MI. 48109兲 Histotripsy is an extracorporeal ablative technology that utilizes microsecond pulses of intense ultrasound to produce nonthermal, mechanical fractionation of targeted tissue. We have previously demonstrated the feasibility of histotripsy ablation in in vivo renal and prostate models. We sought to assess the chronic tissue response, tolerability, and safety of prostate histotripsy in a chronic in vivo canine model. Five acute and thirteen chronic canine subjects were anesthetized and treated with histotripsy targeting the prostate. Pulses consisting of three cycle bursts of 750-kHz ultrasound at a repetition rate of 300 Hz were delivered from a highly focused 15-cm aperture array. Prostates were harvested at 0, 7, 28, or 56 days after treatment. Transrectal ultrasound imaging provided accurate targeting and real-time monitoring of histotripsy treatment. Consistent mechanical tissue fractionation and debulking of prostate tissue was seen acutely and at delayed time points without collateral injury. Canine subjects tolerated histotripsy with minimal hematuria or discomfort. Only mild transient lab abnormalities were noted. Histotripsy is a promising noninvasive therapy for prostate tissue fractionation and debulking that appears safe and well tolerated without systemic side effects in the canine model.

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Contributed Papers 1:30 3pBB4. Improving efficiency of ultrasound histotripsy sources by transmitting at the second harmonic frequency. Timothy A. Bigelow 共Dept. of Elec. and Comput. Eng., Dept. of Mech. Eng., Iowa State Univ., 2113 Coover Hall, Ames, IA 50011, [email protected]兲 Therapeutic ultrasound has shown potential for improving many aspects of medical care in recent years. Therapeutic ultrasound often involves high pressures or intensities, but pressures and intensities in tissue are limited by nonlinear propagation. The impact of nonlinear propagation is most severe for therapies involving cavitation where the peak rarefactional pressure plays the dominate role. As a result, in applications such as histotripsy, the size and power of the ultrasound source must be significantly increased in order to obtain the pressures needed in vivo. In this study, a new ultrasound source design was developed that will help mitigate the effects of nonlinear propagation. Specifically, sound was transmitted at both the fundamental and the second harmonic with the amplitude and phase of the second harmonic designed to counter nonlinear propagation effects for varying source powers from 10 to 500 W. The simulations demonstrated a 30% increase in the peak rarefactional pressure relative to a source where only the fundamental was transmitted when the appropriate phase was used for the second harmonic.

1:45 3pBB5. Skull flexure from blast waves: A mechanism for brain injury with implications for helmet design. William C. Moss, Michael J. King 共Lawrence Livermore Natl. Lab., 7000 East Ave., Livermore, CA 94551, [email protected]兲, and Eric G. Blackman 共Univ. of Rochester, Rochester, NY 14627兲 Traumatic brain injury 关TBI兴 has become a signature injury of current military conflicts. The debilitating effects of TBI are long-lasting and costly. Although the mechanisms by which impacts cause TBI have been well researched, the mechanisms by which blasts cause TBI are not understood. Various possibilities have been investigated, but blast-induced deformation of the skull has been neglected. From numerical hydrodynamic simulations, we have discovered that nonlethal blasts can induce sufficient flexure of the skull to generate potentially damaging loads in the brain, even if no impact occurs. The possibility that this mechanism may contribute to TBI has implications for the diagnosis of soldiers and the design of protective equipment such as helmets. 关This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344兴.

2:00 3pBB6. Cavitation bubble activity during treatment of cortical bones by shock waves. Dorothée Bossis 共CNRS LIP UMR 7623, 15 rue de l’Ecole de Medecine, 75006 Paris, France兲, Frederic Padilla, and Robin O. Cleveland 共Boston Univ., Boston, MA 02114.兲 Shock wave 共SW兲 induced cavitation might be a physical effect by which bioeffects on bones are mediated, especially for SW treatment of bone nonunion. To assess the presence of cavitation and to study bubbles activity at the surface of cortical bones, we treated rat femurs with SWs using a clinical SW therapy device 共Ossatron兲. Sequences of 14 images were acquired using a high speed camera capable of recording up to 100 million frames per second 共Imacon兲. The sequences showed that for all voltage settings of the Ossatron a cloud of cavitation bubbles was induced at the surface of the bone. The bubbles near the surface of the bone appeared to form and act as a single larger bubble, which collapsed violently against the surface of the bone. For a voltage setting of 28 kV the collapse time was measured to be 720 micro-seconds after a single SW and reduced to 620 microseconds after 10 SWs at 1 Hz. In the case of a bone with an artificially fractured surface cavitation events were found to occur preferentially within the fracture gap. Cavitation might therefore be an important mechanisms in the SW treatment of bone defects. 2650


2:15 3pBB7. Shock waves micro-damage induction in cortical bones: Comparison between experimental and simulations results. Frederic Padilla 共Dept. of Mech Eng., Boston Univ., 110 Cummington St., Boston, MA 02115; CNRS LIP UMR 7623, 75006 Paris, France兲 and Robin O. Cleveland 共Boston Univ., Boston, MA 02115兲 Shock waves 共SW兲 are considered a promising method to treat bone non unions. One potential mechanisms of action is the initiation of local microfractures, which may in turn trigger the start of bone healing. In this study, a set of eight intact rat femurs have been subjected to SWs 共peak positive pressure of 40 MPa and peak negative pressure of ⫺8 MPa, PRF of 2 Hz兲. The number of SW was varied from 50 to 1500. Micro-CT images of the specimens were acquired before and after treatment 共16 microns resolution兲. In parallel, numerical simulations were used to quantify the stresses induced by SWs in cortical bone tissue. We used a 3-D FDTD code to solve the linear lossless equations that describe wave propagation in solids and fluids. A 3-D model of a fractured rat femur was obtained from micro-CT data. Results demonstrate that damages were induced in the bone tissues from 150 SWs. Comparison of the location of the induced damages on micro-CT images with predictions of maximum stresses by numerical simulations show that damages principally appeared in regions of highest stresses, suggesting that SW-induced tremendous stresses in bone tissue might be an important mechanisms implied in SW bone therapy.

2:30 3pBB8. Empirical angle-dependent tortuosity functions and sound transmission through cancellous bone. Keith Attenborough 共Dept. of Eng., The Univ. of Hull, Cottingham Rd., Hull HU6 7RX, UK, [email protected]兲 and Haydar Aygun 共Univ. of Hull, Hull HU6 7RX, UK兲 Recent literature concerning the angle dependence of sound transmission through cancellous bone has suggested that it might be due either to elastic anisotropy or to microgeometrical anisotropy in the pore structure; e.g., an angle-dependent tortuosity. The elastic anisotropy approach has been found able to explain the observed variation in fast wave speed with angle better than the angle-dependent tortuosity at the cost of underpredicting slow wave speeds. In reality, it is likely that both influences are present in cancellous bone. Nevertheless the angle-dependent tortuosity approach has been revisited on the basis of orthotropic data for sound transmission through air-filled stereo-lithographical bone replicas 关Attenborough et al., JASA 118, 2779 共2005兲兴. 关Work supported by Leverhulme Grant F/00181/N.兴

2:45 3pBB9. Numerical simulation of propagation of acoustic and elastic waves in human head with fast integral equation solver. Elizabeth Bleszynski, Marek Bleszynski, and Thomas Jaroszewicz 共Monopole Res., 739 Calle sequoia, Thousand Oaks, CA 91360兲 An approach to numerical simulations of acousto-elastic waves in the human head is described, and simulation examples are presented. The primary goal of our work is to construct an efficient and high fidelity numerical simulation tool for investigating such effects as, e.g., acoustic energy transfer to the inner ear via non-airborne pathways. The solver employs a modified form of the volumetric Lippmann–Schwinger integral equation, adapted to high material-contrast problems, and an FFT based stiffness matrix compression implemented for distributed-memory systems enabling large scale 共several million unknowns兲 simulations for realistic geometries. Some of the new aspects of the technique and its applications include 共a兲 extension of the technique for problems involving large density contrasts,in situations involving elastic media; 共b兲improved, more economical, and more accurate Galerkin discretization scheme involving linear tetrahedral elements; 共c兲 verification of the solver by comparison of its predictions with an exact analytical solution for a sphere composed with layers supporting both compressional and shear waves; 共d兲 applications in representative numerical simulations of mechanisms of energy transfer to the inner human ear and 157th Meeting: Acoustical Society of America


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comparative analysis of the pressure distributions in a human head with and without the presence of noise protective devices, carried out with realistic geometry models. 关Work supported by AFOSR兴.

rier transform, which requires a large distance probed by the receivers. Practical constraints, as in clinical inspection of cortical bones, may reduce the inspected spatial length and therefore the efficiency of this technique. We propose a technique which takes benefit of using both multiple emitters and multiple receivers. This approach derived from the DORT method adapted to the transmission problem. The singular values decomposition at different frequencies of the transmission matrix between the arrays give the invariants of transmission, which are linked with the guided modes. First, experiments carried out on different metallic plates are shown. Experimental velocities are in good agreement with Lamb waves theoretical values. In particular, zero group velocity resonance and negative phase velocities are shown. These results allows a good evaluation of the thickness and the transverse and longitudinal bulk waves velocities. Further applications concerning evaluation of elastic properties of cortical bone are finally mentioned.

3:00 3pBB10. Guided waves analysis using multiemitter and multireceiver arrays. Jean-Gabriel Minonzio, Marilyne Talmant, and Pascal Laugier 共Universite Pierre et Marie Curie—Paris 6, Laboratoire d’Imagerie Paramétrique, CNRS LIP UMR7623, 75006 Paris, France兲 Structural and material properties of elastic waveguides can be characterized by fitting measured to theoretical guided wave phase velocities. Here emitters and receivers are placed in contact on the same side of the waveguide 共i.e., axial transmission geometry兲. Multireceiver arrays allow the determination of phase velocities using two-dimensional spatial-temporal Fou-


EXECUTIVE SALON II/III, 1:00 TO 2:00 P.M. Session 3pID

Interdisciplinary: Hot Topics in Acoustics Paul E. Barbone, Chair Dept. of Aerospace and Mechanical Engineering, Boston Univ., Boston, MA 02215 Invited Papers 1:00 3pID1. Hot topics in youth education outreach. Grace Klonoski 共Optical Society of America, 2010 Massachusetts Ave., N.W., Washington, DC 20036-1012兲 This presentation will focus on ways in which professional societies and their volunteers can make a lasting, positive difference in supporting the science and math learning of young students. The introduction will provide a brief overview of trends in student achievement in math and science and will discuss the availability of qualified teachers in the United States. Four features of effective learning environments will be described. The remainder of the presentation will be devoted to examples of how scientific communities can become directly involved in reaching out to students on a local and global scale. A variety of youth programs hosted by the Optical Society of America 共OSA兲 and the OSA Foundation will be highlighted with an emphasis on the scope, goals, and quantitative results of each initiative. From a multilingual Web site that provides students, teachers, and parents with basic science information, lesson plans, and hands-on activities, to the production and worldwide distribution of “optics suitcases” that give students the opportunity to participate in hands-on demonstrations, OSA’s recent efforts have benefited thousands of individuals in more than 20 countries. The planned collaboration between ASA and OSA to develop acoustics-focused classroom materials, a Web site, and demonstration kit will be described. 1:20 3pID2. Auditory attention and the active listener. Barbara Shinn-Cunningham 共Cognit. and Neural Systems, 677 Beacon St., Boston, MA 02215兲 Traditionally, psychoacousticians and auditory physiologists have focused on how stimulus properties affect perceptual abilities, measuring just-detectable differences in different acoustic attributes or thresholds for audibility of different sounds. However, in everyday settings with more than one audible sound source, these low-level abilities are often not the factors limiting understanding of an important sound source. Instead, the way the brain organizes sound and focuses attention has an enormous impact on what we actually hear and analyze out of an auditory scene. Recent studies in both perceptual and physiological acoustics are working to uncover how the intentions and goals of the listener influence processing of sound in the brain. This talk will review some recent advances in auditory neuroscience that demonstrate the importance of top-down attention on neural processing and perception of sound. 1:40 3pID3. Hot topics of signal processing in acoustics. Ning Xiang 共Graduate program in Archit. Acoust., Rensselaer Polytech. Inst., Troy, NY, 12180兲 and David Chambers 共Lawrence Livermore Natl. Lab., Livermore, CA 94551兲 Signal processing is used to some extent in all areas of acoustics, such as extracting relevant information from acoustic measurements made either in the laboratory or in the field, processing signals and/or synthesizing data to cope with demanding tasks raised in acoustics. Techniques range from simple classical approaches based on Fourier transforms and Gaussian noise, to sophisticated modelbased techniques that incorporate physical/parametric models of the acoustical system. In this paper we highlight new approaches to 2651




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signal processing that could be applied to a broad variety of acoustical problems. These include coded signals for architectural-acoustics, acoustical communications, and medium characterization, Bayesian methods for room acoustics, physical acoustics, and underwater acoustics including highly nonlinear problems with non-Gaussian noise, and extensions to the familiar Kalman filtering to nonlinear models. Examples of each approach will be shown that illustrate the advantages and disadvantages of each technique. Additional topics may be discussed as time allows.


PARLOR B/C, 1:00 TO 2:30 P.M. Session 3pMUa

Musical Acoustics: Acoustics of Bagpipes D. Murray Campbell, Chair School of Physics and Astronomy, Univ. of Edinburgh, Edinburgh EH9 3JZ, U.K.


Invited Papers

1:05 3pMUa1. An introduction to bagpipes of the world. Paul A. Wheeler 共Dept. of Elec. & Comput. Eng., Utah Stat Univ., 4120 Old Main Hill, Logan, UT 84322-4120兲 When one hears the term “bagpipe,” the Great Highland bagpipe from Scotland comes to mind. There are actually several types of bagpipes played across Europe and the Middle East, each with its unique characteristics. This paper classifies bagpipes from around the world based on their construction and acoustic properties. These include: method of filling the bag 共bellows versus mouth pipe兲, bag properties and materials, reeds 共single or double兲, pipes used for chanters and drones 共cylindrical or conical兲, and general characteristics of the instrument. The objective of this overview paper is to provide the background for more detailed papers in the session on bagpipes.

1:30 3pMUa2. A brief history and acoustical analysis of the great highland bagpipe. Stanley A. Cheyne 共Dept. of Phys. and Astronomy, Hampden-Sydney Coll., Hampden-Sydney, VA 23943兲 A brief history and analysis of the great highland bagpipe will be discussed. Although the bagpipe may have originated several thousands of years ago, the great highland bagpipe, distinguished by three drones and a chanter, is only a few hundred years old. A discussion of the components and operation will be given. In addition, spectral analysis of the drones and chanter will be discussed and how the harmonic content of the drones support the notes played on the chanter. A spectral analysis and sound pressure levels of chanter reeds of varying ages, strengths, and materials will also be presented.

2:00 3pMUa3. Tuning and tone quality of bagpipe drones. R. Dean Ayers 共Phys. Dept., Southern Oregon Univ., 1250 Siskiyou Blvd., Ashland, OR 97520, [email protected]兲 and Peter R. Nordquist 共Southern Oregon Univ., Ashland, OR 97520兲 Tunes are played on the Great Highland bagpipe using the tone holes of its conical chanter. The much quieter practice chanter has holes with the same spacings on a narrow cylindrical bore. Differences between spherical waves in a cone and plane waves in a cylinder give rise to striking differences in pitch and tone quality. Drone pipes do not need to fit into either the conical family or the closed-pipe family of reed woodwinds, because each drone produces only one note. A bass drone has three cylindrical segments, with diameters that increase in sequence, followed by an expansion chamber 共bell and constricting cap兲 at the output end. Tuning slides between the cylinders create two additional expansion chambers with large diameters and adjustable lengths. 共A tenor drone has two cylinders and one tuning slide.兲 Sound waves incident from either direction experience strong reflections at each jump in diameter, resulting in uneven standing waves and irregular input impedance curves that would be impractical for pipes with tone holes. Experimental results and computer models are used to relate the shape of a drone’s air column to its tuning and tone quality. 关Work supported by the Paul S. Veneklasen Research Foundation.兴

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PARLOR B/C, 2:30 TO 3:30 P.M. Session 3pMUb

Musical Acoustics: Bagpipe Lecture and Concert D. Murray Campbell, Chair School of Physics, Univ. of Edinburgh, Edinburgh EH7 3JE, UK Kevin Carr, a bagpipe performer will demonstrate and discuss various bagpipes from around the world.


BROADWAY III/IV, 12:55 TO 3:00 P.M. Session 3pPA

Physical Acoustics: Influence of Temperature on Sound in Condensed Matter Albert Migliori, Chair Los Alamos National Lab., Los Alamos, NM 87545


Invited Papers

1:00 3pPA1. Precise sound velocity measurements on solids and liquids at high pressure and high temperature with direct length measurement. Baosheng Li 共Mineral Phys. Inst., Stony Brook Univ., Stony Brook, NY 11794, [email protected]兲 Sound velocity measurements at pressure and/or temperature provide important information in the material’s structural behavior and physical properties under extreme conditions. With the application of synchrotron X-radiation sources, new developments have emerged to facilitate the study properties and structures of crystalline and amorphous materials. In the last decade, we have developed a unique technique for measuring sound velocity in a cubic type multianvil apparatus installed at X-17B2, National Synchrotron Light Source 共NSLS兲 of Brookhaven National Lab, which allows us to conduct precise velocity measurements on crystalline and noncrystalline materials at various pressure and temperature conditions by conducting simultaneous X-radiation and ultrasonic interferometry measurements. In this paper, sound velocities at high temperatures for some ceramics and metals are measured to study the behavior and property change of these materials undergoing compression/expansion as well as phase transition and structural instabilities. This technique opens new opportunities for the study of materials that are of interest to many disciplines, such as earth science, materials science, and condensed matter physics.

1:25 3pPA2. The influence of grain structures on resonance behavior near phase transitions. Timothy W. Darling, Gunes Kaplan 共Phys. Dept.-NTF Univ. of Nevada, 1664 N. Virginia St., Reno, NV 89557兲, James A. TenCate 共Los Alamos Natl. Lab., Los Alamos, NM 87545兲, Ruth E. A. McKnight, and Michael A. Carpenter 共Univ. of Cambridge, Downing St., Cambridge, UK兲 Inhomogeneities such as grains or plastically deformed regions in materials locally change sound wave velocities and introduce scatter in the pattern of expected resonance frequencies. The accompanying variation in the components of the free energy may promote, or block, nucleation and growth of new phases near transition temperatures. Lanthanides and martensites are two groups of materials with complex phase structures where control of the phase transformation is important in technological applications. Complex oxide minerals with a wide variety of phase structures are important in understanding the behavior of the earth’s crust. The influence on mechanical resonances of both the micro 共meso兲 structures and the appearance and growth of phases near transition temperatures will be discussed. Experimental data on resonance behavior in inhomogeneous materials 共largely lanthanides, transition metals, and silicates兲, where attempts have been made to control the scale and type of microstructure as they approach phase transitions will be presented. 关This work receives support from DOE Grant No. DE-FC52-06NA27616 through the University of Nevada Terawatt Facility.兴 2653




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1:50 3pPA3. Temperature dependence of elastic moduli for polycrystalline Pu: Comparison of alpha and gamma phases. I.R. Stroe 共Worcester Polytechnic Inst., 100 Institute Rd., Worcester, MA 01609, [email protected]兲, J. B. Betts, C. Pantea, A. Trugman, J. N. Mitchell, M. Ramos, F. Freibert, C.H. Mielke, and A. Migliori 共Los Alamos Natl. Lab., Los Alamos, NM 87544兲 The elastic properties of pure polycrystalline Pu were investigated as a function of temperature by resonant ultrasound spectroscopy. For both alpha and gamma phase, shear 共G兲 and longitudinal 共CL兲 elastic moduli were determined simultaneously and the bulk modulus 共B兲 was computed from them. In alpha phase, G and B exhibit the same temperature dependence, but an unusually large change. This behavior together with a high Gruneiser parameter and an almost temperature independent Poisson ratio is attributed to the 5-f electron localization delocalization. In the gamma phase, G and B show anomalous temperature behavior: G decreases with temperature while B is near temperature independent. The Poisson ratio increases with temperature by 4%. This normal behavior of the Poisson ratio is unusual for Pu.

Contributed Papers 2:15 3pPA4. Stability of monitoring weak changes in multiply scattering media with ambient noise correlation: Laboratory experiments. Larose Eric, Hadziioannou Celine, Coutant Olivier, Roux Philippe, and Campillo Michel 共Lab. de Geophysique interne et Tectonophysique, CNRS & Univ. J. Fourier, Grenoble, France兲 Previous studies have shown that small changes can be monitored in a scattering medium by observing phase shifts in the coda. Passive monitoring of weak changes through ambient noise correlation has already been applied to seismology, acoustics, and engineering. Usually, this is done under the assumption that a properly reconstructed Green function as well as stable background noise sources are necessary. In order to further develop this monitoring technique, we performed a laboratory experiment in the 2.5 MHz range in a gel with scattering inclusions, comparing an active 共pulseecho兲 form of monitoring to a passive 共correlation兲 one. Our results show that temperature changes in the medium can be observed even if the Green function 共GF兲 of the medium is not reconstructed. Moreover, we establish that the GF reconstruction in the correlations is not a necessary condition: the only condition to monitoring with correlation 共passive experiment兲 is the relative stability of the background noise structure. 2:30 3pPA5. Temperature variation of Young’s modulus and elastic wave speed in a mixture of solid-particles in liquid. Hasson M. Tavossi 共Dept. of Phys., Astronomy and Geosciences, Valdosta State Univ., 1500 No. Patterson St., Valdosta, GA 31698兲 The variation of ultrasonic wave speed in the solid-liquid mixtures as a function of temperature is studied. The goal of this investigation is to determine temperature dependence of the elastic moduli of materials consisting of different size solid particles. The elastic wave speed in solids is assumed

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to be proportional to the square root of Young’s modulus of the material. Elastic wave speed in the material is related to the variation of Young’s modulus of the solid constituents. Also considered are temperature dependence of the wave attenuation, by scattering and absorption, and the effects of phonon modes, their amplitude and frequency, on the elastic moduli and wave dispersion in the material. Previous experimental data have shown a decrease in elastic moduli at the contact points of solid particles with increase in elastic wave frequency. Findings on the variations of elastic wave speed in solids with temperature and frequency are compared to analyze any similarity between the effect of wave frequency increase and temperature increase.

2:45 3pPA6. Resonant ultrasound spectroscopy studies of Fe-based superconductors. Veerle Keppens, Lindsey VanBebber, Yanbing Luan 共Dept. Mater. Sci. and Eng., The Univ. of Tennessee, Knoxville, TN 37996兲, Michael A. McGuire, Athena Sefat, Brian C. Sales, and David Mandrus 共Oak Ridge Natl. Lab., Oak Ridge, TN 37831兲 The discovery of high superconducting transition temperatures in Febased compounds has generated a frenzy of experimental and theoretical research activities on these systems. Whereas doping is required to establish superconductivity, careful studies of the undoped materials are important to elucidate the underlying physics. Recently, resonant ultrasound spectroscopy measurements were carried out on the undoped oxypnictide system LaFeAsO as well as the oxygen-free systems BaFe2As2 and Ba共Fe, Co兲2As2. The elastic response of the parent compounds shows a very gradual softening corresponding to the structural transition that characterizes these systems. Remarkably, this softening persists in the superconducting samples, even though the structural transition in these compounds is suppressed.



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GALLERIA NORTH AND SOUTH, 1:00 TO 3:20 P.M. Session 3pSC

Speech Communication: Lexical Effects and Perceptual Processing in Speech (Poster Session) Eric A. Vatikiotis-Bateson, Chair Dept. of Linguistics, Univ. of British Columbia, Vancouver, BC V6T 1Z1, Canada All posters will be on display from 1:00 p.m. to 3:20 p.m. To allow contributors an opportunity to see other posters, all contributors of odd-numbered papers will be at their posters from 1:00 p.m. to 2:10 p.m. and contributors of even-numbered papers will be at their posters from 2:10 p.m. to 3:20 p.m.

Contributed Papers 3pSC1. Phonetic experience with specific words affects categorical perception of those words. Mark VanDam 共Boys Town Natl Research Hospital, 555 N. 30 St., Omaha, NE 68131, [email protected]兲 and Robert F. Port 共Indiana Univ., Bloomington, IN 47405兲 How does experience with specific words influence linguistic-phonetic categories? Listeners were trained over a five-session, listen-and-repeat task on a set of target words embedded in continuous speech and altered so that the initial stop consonant voice-onset time 共VOT兲 was 80% longer than natural. Voicing boundaries were estimated before and after training using a two-alternative, forced-choice perceptual task on an eight-step VOT continuum. Stimuli were highly natural tokens by two stimulus talkers. Part 1 of the experiment asked whether exposure to lengthened forms would influence location of the voicing boundary, and, if so, whether that effect would generalize to similar forms. Results showed longer boundaries after exposure to lengthened VOTs for the trained forms, but lengthening did not generalize to new forms. Part 2 investigated voicing boundary locations as a function of lexical status 共word, nonword兲 and usage frequency 共high, low兲. Boundary locations indicated expanded VOT regions both for nonwords over words 共opposite to the Ganong effect兲 and for high-frequency words over low-frequency words; neither lexical status nor usage frequency interacted with training. Results suggest a lexical sensitivity to low-level speech cues, thus offering support for a rich memory language model. 3pSC2. Were we or are we? Perception of reduced function words in spontaneous conversations. Natasha Warner, Dan Brenner, Anna Woods 共Box 210028, Univ. of Arizona Dept. of Linguist., Tucson, AZ 85721-0028兲, Bejamin V. Tucker 共Univ. of Alberta, Edmonton, AB, Canada T6G 2E7兲, and Mirjam Ernestus 共Univ. Nijmegen, Nijmegen AH6500, the Netherlands兲 Spontaneous, reduced pronunciations diverge greatly from citation forms. The quality of a single segment can change, e.g., /b/ in “about” surfacing as an approximant. But sounds, syllables, and entire words can also be deleted 共e.g., “do you have time?” as 关djutEm兴 with no acoustic trace of “have”兲. This work investigates the perception of reduced function words such as “he was” or “we were.” Twenty-two young American English speakers’ spontaneous conversations with close acquaintances were recorded. From these, we selected utterances containing items such as “he’s/he was, we’re/we were, got him/got them.” When hearing an entire utterance, native listeners may clearly perceive “we were,” but on hearing just the “we were” portion, they perceive an unambiguous “we’re.” The portion of the signal presented to listeners is manipulated to determine the contributions of local acoustic cues, speech rate and coarticulation, semantic and syntactic information, and overall bias toward present vs past tense. An auditory and a written task are also compared to separate the contribution of intonation from that of syntax/semantics. These results begin to elucidate the interplay of information sources listeners draw upon when parsing spontaneous speech. Future work will compare to non-native listeners’ perceptions. 3pSC3. The roles of tone and syllable structure in Mandarin spoken word recognition. Yuwen Lai 共Dept. of Linguist., Univ. of British Columbia, 2613 West Mall, Vancouver, BC V6T 1Z4, Canada兲 and Jie Zhang 共Univ. of Kansas, Lawrence, KS 66044-3177兲 2655


The present study adopts the gating paradigm to investigate the roles of tone, onset sonorancy, and nasal coda in Mandarin spoken word recognition. Duration-blocked gates generated from eight monosyllabic quadruplets with matching frequencies of occurrence were used as stimuli. The initial consonant of each syllable formed the first gate, with later gates formed by 40 ms increments. Twenty-eight native Mandarin speakers from Beijing were asked to identify each gated stimulus by writing down the Chinese characters. Isolation point 共IP兲 based on correct tone identification as well as overall correct word identification 共correct onset, rhyme, and tone兲 were collected. Results from both conditions showed that tone 1 has an earlier IP than tone 4, which has an earlier IP than tones 2 and 3. Sonorant-initial syllables have an earlier IP than obstruent-initial syllables, but further analyses of covariance indicated that this is due to the fact that IP covariates with the duration of the initial consonant. Syllables without a nasal coda have an earlier IP than syllables with a nasal coda. This effect might be due to the interference of nasalization on tone perception or the delayed tonal contour realization due to the nasal coda 关Xu, 共1998兲兴. 3pSC4. Duration and context speech rate as cues to lexical perception and word segmentation. Molly J. Henry, Laura C. Dilley, Louis N. Vinke, and Christopher J. Weinland 共Dept. of Psychol., Bowling Green State Univ., Bowling Green, OH 43403, [email protected]兲 Duration and speech rate are traditionally assumed to be filtered out before lexical lookup takes place, although these factors are known to influence phoneme perception. Here, the hypothesis was investigated that duration can affect both perceived lexical identity, as well as the perceived number and implied locations of word boundaries relative to the speech signal. Experiment 1 was a production study which investigated durations of vocalic portions of phonetically similar versions of target word strings which differed in their number of syllables 共e.g., cease versus see us兲; these target word strings were spoken in semantically neutral context sentences. As expected, vocalic durations in target strings with fewer syllables were shorter than those with more syllables. In Experiment 2, the relative durations of vocalic portions of target strings in sentences from Experiment 1, as well as sentential context speech rate, were manipulated using speech resynthesis. Relative duration and context speech rate both affected the words that participants heard, as well as the implied number of phonemes and imputed locations of word boundaries. These findings indicate that duration plays a significant and underinvestigated role in spoken word recognition and word segmentation. 3pSC5. The spread and density of the phonological neighborhood can strongly influence the verbal transformation illusion. James A. Bashford, Jr., Richard M. Warren, and Peter W. Lenz 共Dept. of Psychol., Univ. of Wisconsin-Milwaukee, P.O. Box 413, Milwaukee, WI 53201兲 When a recorded verbal stimulus repeats over and over, adaptation occurs and listeners hear competing forms. Reports of these “verbal transformations” 共VTs兲 were obtained for 36 consonant-vowel 共CV兲 syllables that varied both in frequency-weighted neighborhood density 共ranging from 12.73 to 90.42兲 and in neighborhood spread 关i.e., for 18 CVs, changes at either phoneme position could yield real words 共spread ⫽ 2兲 while for the remaining 18 CVs, changes at only one position could yield words 共spread 157th Meeting: Acoustical Society of America


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⫽ 1兲兴. The strength of the VT illusion, measured by the amount of time the stimuli were heard nonveridically during the 300-s repetition period, decreased substantially with both increasing neighborhood density 关r⫽⫺0.74, F共1,34兲⫽42.6, p⬍0.0001兴 and increasing spread 关r⫽⫺0.75, F共1,34兲 ⫽ 44.1, p⬍0.0001兴. Stepwise regression revealed that density and spread collectively accounted for approximately 70% of the variance in illusion strength 关F共1,33兲艌10.0, p⬍0.003 or better兴. These effects are larger than, but generally consistent with, neighborhood effects obtained with other psycholinguistic tasks, and they suggest that VTs can provide a highly sensitive measure of lexical competition. 关Work supported by NIH.兴 3pSC6. Using auditory feedback during vocalization: Different mechanisms for utterance onset and pitch maintenance. Colin S. Hawco and Jeffery A. Jones 共Dept. of Psych., Wilfrid Laurier Univ., 75 University Ave. West, Waterloo, ON N2L 3C5, Canada兲 During vocalization, auditory feedback is used to attain and maintain a desired fundamental frequency 共F0兲. The use of auditory feedback to control vocalization has been studied using adaptation studies, in which an F0 feedback alteration is maintained across many trials, and using midutterance perturbations, where a brief F0 change is introduced during an ongoing utterance. Participants vocalized during two blocks. In an adaptation block, a one semitone F0 shift was maintained for 40 trials, and midutterance perturbations were introduced by removing the feedback alteration. In a control block, a midutterance perturbation was introduced in trials, which were either unshifted or shifted randomly by one semitone at before the onset of vocalization 共similar to the adaptation trials兲. F0 compensation to midutterance perturbations was identical in all conditions, and was always smaller than the compensation to a shift at utterance onset. These results are explained by a change in the control strategy at utterance onset and midutterance. At utterance onset, auditory feedback is compared to feedback predicted by a forward model to ensure the pitch goal is achieved. However, after utterance onset, the control strategy switches and stabilization is maintained by comparing feedback to previous F0 production. 3pSC7. Auditory-phonetic projection and lexical structure in the recognition of sine-wave words. Robert E. Remez, Kathryn R. Dubowski, Robin S. Broder, Morgana Davids, Yael S. Grossman, Marina Moskalenko, Jennifer S. Pardo, and Sara Maria Hasbun 共Dept. of Psych., Barnard College, Columbia Univ., 3009 Broadway, New York, NY 10027, remez @columbia.edu兲 Speech remains intelligible despite the elimination of canonical acoustic correlates of phonemes from the spectrum. Listeners tolerate distortion or spectral blur in tone analogs, noise band vocoded speech, and acoustic chimeras in utterances ranging from syllables to isolated words and sentences. A portion of this flexibility is attributable to short-term perceptual learning in auditory-to-phonetic projection, though exploiting the properties of lexical neighborhoods plays a role with utterances composed of words. New tests were conducted to estimate talker learning, segmental sensitivity, and lexical knowledge in this kind of perceptual versatility. Sine-wave versions of the easy/hard word lists were created, and the performance-level difference between the two lists was used to index the default reliance on lexical processes. Several kinds of preliminary exposure were used to induce sensitivity to a dimension of perceptual learning: sine-wave speech produced by the same talker, sine-wave speech of a different talker, natural speech of the same talker. A comparison of exposure effects on the performance level of easy/hard word recognition offered a clue about the differential contribution of talker-based, segment-based, and lexically-based attention in speech perception without canonical spectra. Implications for perceptual accounts based on cue likelihood will be discussed. 关Work supported by NIDCD.兴 3pSC8. Function words of lexical bundles: The relation of frequency and reduction. Shannon F. Lemke, Antoine Tremblay, and Benjamin V. Tucker 共Dept. of Linguist., Univ. of Alberta, 4-32 Assiniboia Hall, Edmonton, AB, Canada, T6G 2E7, [email protected]兲 Studies of spontaneous speech have shown frequency effects on the amount of reduction produced by speakers, demonstrating that predictability facilitates production of a target word 关Shi et al. 共2005兲; Jurafsky et al. 共2001兲; Bell et al. 共2003兲兴. This paper investigates the amount of reduction produced in laboratory recorded speech and considers the effect of frequency on the duration of function words in four-word sequences. It is also 2656


found that the influence of frequency has an effect on holistically storing these bundles. An interaction between word position and the third-order transitional probability 共ABC → D兲 has been established, indicating that greater third-order transitional probabilities predict shorter function word durations in the first and second positions of a bundle, and, therefore, involve more durational reduction. The current research shows that, just as frequency affects reduction in spontaneous speech, there is an effect in laboratory produced speech as well. These findings indicate that multiword sequences are stored as lexical units. 3pSC9. Basic word segmentation abilities emerge earlier in infancy than previously thought. Elizabeth K. Johnson 共Dept. of Psych., Univ. of Toronto Mississauga, 3359 Mississauga Rd. North, Mississauga, ON L5L 1C6, Canada, [email protected]兲 and Amanda Seidl 共Purdue Univ., West Lafayette, IN 47907兲 English-learning 7.5- but not 6-month-olds extract word forms from fluent speech 共Jusczyk et al., 1999兲. Thus, English learners are thought to begin segmenting words from speech by 7.5 months. However, recent research has shown that when target words are flanked by a frequent and emotionally salient word 共e.g., the infant’s name兲, even 6-month-olds can extract words from speech 共e.g., Bortfeld et al., 2005兲. This suggests that basic word segmentation capabilities may emerge earlier than past studies have suggested. Using the Headturn Preference Procedure, we tested 6-month-olds’ ability to segment utterance-flanked words from speech, e.g., “geff” from “At the circus we met a silly geff.” Infants were familiarized with passages containing target words in utterance initial and final position, and then tested on their recognition of these words in isolation. A significant looking time difference to familiar versus unfamiliar words was found, indicating that 6-month-olds segmented the target words from speech. Six-month-olds’ success at segmenting utterance-flanked words from speech is particularly interesting because infant-directed speech consists of short utterances containing many utterance-flanked words. Segmentation of utterance-flanked words could help infants learn the cues needed to extract harder utterance-medial words from speech 共see Seidl and Johnson, 2006兲. 3pSC10. Phonological competition during the recognition of spontaneous speech: Effects of linguistic context and spectral cues. Susanne Brouwer, Holger Mitterer, and Falk Huettig 共MPI for Psycholinguistics, P.O. Box 310, 6500 AH Nijmegen兲 How do listeners recognize reduced forms that occur in spontaneous speech, such as “puter” for “computer”? To this end, eye-tracking experiments were performed in which participants heard a sentence and saw four printed words on a computer screen. The auditory stimuli contained canonical and reduced forms from a spontaneous speech corpus in different amounts of linguistic context. The four printed words were a “canonical form” competitor 共e.g., “companion”, phonologically similar to “computer”兲, a “reduced form” competitor 共e.g., “pupil”, phonologically similar to “puter”兲, and two unrelated distractors. The results showed, first, that reduction inhibits word recognition overall. Second, listeners look more often to the “reduced form” competitor than to the “canonical form” competitor when reduced forms are presented in isolation or in a phonetic context. In full context, however, both competitors attracted looks: early rise of the “reduced form” competitor and late rise of the “canonical form” competitor. This “late rise” of the “canonical form” competitor was not observed when we replaced the original /p/ from “puter” with a real onset /p/. This indicates that phonetic detail and semantic/syntactic context are necessary for the recognition of reduced forms. 3pSC11. Lexical access across different voices. Rochelle S. Newman 共Dept. Hearing & Speech Sci., and Program in Neurosci. and Cognit. Sci. Univ. of Maryland, 0100 Lefrak Hall, College Park, MD 20742, rnewman @hesp.umd.edu兲 In many real-world situations, listeners may be trying to attend to one individual while other voices are speaking in the background. These separate streams of sound hit the ear simultaneously. Within a single stream, research has investigated the extent to which lexical activation is limited by word boundary information. For example, Gow and Gordon 共1995兲 found that multiple-word sequences such as “two lips” may activate words such as “tulips” despite the presence of acoustic cues to a word boundary in the middle of the sequence. Yet, no studies have examined whether lexical ac157th Meeting: Acoustical Society of America


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cess could “cross” signals entirely. In a series of four experiments, we test whether lexical access might 共ever兲 cross talker boundaries. We find that when listeners hear two words spoken by two different voices 共for example, a male saying “two” followed by a female saying “lips”兲 they still activate the larger cross-voice word “tulips,” despite the presence of strong cues to an acoustic boundary. 关Work supported by NSF.兴 3pSC12. Speaking rate modulates lexical competition in online speech perception. Eva Reinisch, Alexandra Jesse 共Max Planck Inst. for Psycholinguistics, Wundtlaan 1, 6525XD Nijmegen, The Netherlands, [email protected]兲, and James M. McQueen 共Radboud Univ. Nijmegen, and Max Planck Inst. for Psycholinguistics, Nijmegen, The Netherlands兲 Durational cues are used in online word recognition to disambiguate Dutch phrases such as “een共s兲共s兲peer” 关“on共c兲e 共s兲pear”兴: The longer the 关s兴, the more likely listeners consider the target to be 关s兴-initial 关K. E. Shatzman and J. M. McQueen, Perc. Psychophys. 68, 1–16 共2006兲兴. Here, a series of eye-tracking experiments show that speaking rate affects perception of duration and thus modulates lexical competition online. Listeners’ eyemovements were recorded while they listened to sentences such as “Ze heeft wel eens peer gezegd” 共“She once said pear”兲. Listeners had to click on printed targets 共peer兲 presented on a computer screen with an 关s兴-initial competitor 共speen; “pacifier”兲 and two unrelated distractors. When the preceding context is faster, the critical 关s兴 should sound longer and match better the beginning of “speen.” Listeners indeed looked at the 关s兴-initial competitors more following fast than slow contexts. The opposite was found for 关s兴-initial targets 共sneeuw; “snow”兲 with non-关s兴-initial competitors 共neef; “nephew”兲. Context adjacent to the target 共i.e., wel eens兲 influenced target perception more than nonadjacent context. Nonadjacent context, however, was sufficient to modulate competition when adjacent context was spoken at the same rate as the target. Amount of nonadjacent context at a given rate affected only off line categorization. 3pSC13. The nonaccommodation of speech errors. Andrea Gormley 共Inst. of Cognit. Sci. Rm. 2222, Dunton Tower, Carleton Univ., 1125 Colonel By Dr. Ottawa, ON K1S 5B6, Canada, [email protected]兲 Word-form speech errors are assumed to adapt to the unintended environment. For example, in the error ‘bads cat’ for intended ‘bad cats,’ the plural marker ‘s’ assimilates to the voicing of the ‘d’ in ‘bad.’ This phenomenon, called accommodation, provides evidence that the component responsible for errors is processed before the phonological assimilation component. Previous work on accommodation relies on the researcher to detect accommodation 关D. Boomer and J. Laver, Br. J. Disord. Commun. 3, 1–12 共1968兲兴. Given that these studies are prone to perceptual bias, the conclusion that accommodation is the norm remains open. An acoustic analysis of errors was conducted to re-address this question. Thirty-two nonword tongue twisters, e.g., ‘tiff tivv tivv tiff,’ were designed to induce voicing errors on the coda. Because vowel lengthening before voiced codas is a phonological process in English, vowel length can be measured to detect accommodation. Errors were determined for each participant by measuring coda percent voicing and vowel duration in a control condition. Results from six participants 共872 errors兲 show that while errors do accommodate 共7.6%兲, nonaccommodation 共40.7%兲 occurs more frequently. This result shows that errors do occur after phonological processing. 关Work supported by OGS and Carleton University.兴 3pSC14. Planning time effects of phonological competition: Articulatory and acoustic data. Christine R. Mooshammer 共Haskins Labs., 300 George St., New Haven, CT 06511, [email protected]兲, Louis Goldstein 共USC, CA兲, Mark Tiede 共MIT Res. Lab of Electron., MA兲, Manisha Kulshreshtha 共Haskins Labs.,兲, Scott McClure, and Argyro Katsika 共Haskins Labs.,兲 One major cause for speech production variability and errors is competition between phonologically similar sequences in an utterance. Since one recent model of speech production planning 关Nam 共2004兲兴 also posits a systematic relation between planning time and kinematic variability, we decided to directly investigate whether competition increases planning time, i.e., whether it takes longer to initiate a sequence such as “tape cape” compared with “tape tape.” Effects of competition in the onset were compared to competition in the coda 共e.g., “tape take”兲. Results from two studies are reported: articulatory latencies from a delayed naming task recorded using EMA 共four speakers兲, and acoustic latencies from a delayed naming task, a 2657


simple naming task, and a picture naming task 共ten speakers兲. Latencies were significantly affected by competition, i.e., latencies were longer for items like “tape cape” and “tape take” than for “tape tape.” However, no significant differences were found in competition effects between onset and coda positions. Apart from latency, overall duration increased and clusters formed across words showed less overlap. Observed effects on latency were largest for picture naming, followed by simple naming and least for delayed naming. 关Work supported by NIH DC008780.兴 3pSC15. Color effects in audiovisual spoken word recognition. Rachael Frush Holt, Tessa Bent 共Dept. of Speech and Hearing Sci., Indiana Univ., 200 S Jordan Ave., Bloomington, IN 47405, [email protected]兲, and Luis Hernandez 共Indiana Univ., Bloomington, IN 47405兲 Although the importance of the visual contribution to speech perception has been known for over 50 years, strong interest in audiovisual speech perception has emerged only recently. In developing a test of audiovisual sentence recognition, white balancing and color correcting 共adjusting the whites, mids, and black bandwidths to compensate for the camera’s inability to fully reproduce human eyesight color spectrum兲 improved visual-only spoken word recognition. No differences were found in audiovisual or auditory-only modalities. Although improvement was seen across all key words, those with more visible phonemes showed the greatest improvement. To further examine the effects of color in the audiovisual modality specifically, the original speech signal was replaced with a signal-correlated noise and presented to adults in one of three conditions: non-color-corrected, color-corrected, and color-inverted. Minimal speech cues were sufficient for overcoming performance decrements due to small, but not large, color disturbances. Furthermore, in the color-corrected condition, performance in visual-only and signal-correlated noise conditions were equivalent, whereas in the non-color-corrected condition, signal-correlated noise improved performance over visual-only. The results suggest that consideration of minor color disturbances is warranted if testing visual-only perception; however, significant color disturbances can cause decrements in audiovisual conditions, as well. 关Work funded by the AHRF.兴 3pSC16. Perception of voiced-only and noise-vocoded speech by a language-trained chimpanzee (Pan troglodytes). Lisa A. Heimbauer 共1527 Pangborn Station Dr. Decatur, GA 30033, [email protected]兲, Michael J. Beran, and Michael J. Owren 共Georgia State Univ., Atlanta, GA 30302-5010兲 The ability of human listeners to understand speech even in altered or synthetic forms is argued to be evidence of uniquely human processing abilities. However, extensive early experience with speech may also contribute to this capability. To investigate this issue two experiments were designed to test the ability of Panzee, a 22-year-old language-trained chimpanzee, to recognize words in synthetic form. Like a human child, she was reared from infancy by human caregivers who routinely spoke to her. She communicates with humans by identifying words using graphical symbols 共lexigrams兲. Experimental training and testing were conducted with two different sets of 24 familiar words presented one-per-trial in natural, voicedonly, or noise-vocoded forms, with Panzee choosing one of four lexigrams presented on a computer monitor. Experiment 1 showed equivalent performance with words heard in natural form versus voiced-only versions, resynthesized from only voiced components of a word. Noise-vocoded words presented in Experiment 2 simulated effects of hearing using a cochlear implant and were based on amplitude-modulated noise bands. Performance with these sounds was significantly higher than chance, but also lower than with natural words. Results suggest specialized processing mechanisms are not necessary to speech perception in the absence of traditional acoustic cues. 3pSC17. Identifying the common problems of English-to-Japanese consecutive interpretations performed by Japanese intepreting students. Kinuko Takahashi 共Sophia Univ. #306, 4-1-10, Dai, Kamakura-city 2470061 Japan, [email protected]兲 The purpose of the present paper is to identify the problems that Japanese interpreting students may encounter and to establish causes for them in the expectation that they may help devise a training method. It has been long wondered why some students become successful interpreters and others do not. In order to answer this question, the research was launched to identify the problems that interpreting students encountered. For this purpose, nine 157th Meeting: Acoustical Society of America


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interpreting students were asked to consecutively interpret four different English texts. It was discovered that the participants had a tendency for omissions of interpreting, and omissions occurred due to a number of causes. One of them was a problem of speech perception. One of the participants, for example, was not able to distinguish “breeze” from “bleed.” To one of the participants, “attendance” sounded like “tendence.” These problems seemed to require the participants to take more time to interpret. As a result, the participants failed to listen to the following parts, eventually making further omissions. Therefore, it is necessary for the participants to learn “top-down” processing of comprehension. However, it is necessary to examine the relation between the level of interpreting skills and speech perception ability. 3pSC18. Perceptual normalization for variation in speaking style. Antonia D. Vitela, Sarah C. Sullivan, and Andrew J. Lotto 共Speech, Lang. and Hearing Sci., Univ. of Arizona, 1131 E. 2nd St., Tucson, AZ 85721, [email protected]兲 Ladefoged and Broadbent 关J. Acoust. Soc. Am. 29, 98–104 共1957兲兴 demonstrated that listeners will shift their categorization of a target vowel as a function of acoustic characteristics of a preceding carrier phrase. These results have been interpreted as an example of perceptual normalization for variability resulting from differences in talker anatomy. The present study examined whether listeners would normalize for acoustic variability resulting from differences in speaking style within a single talker. Two vowel series were synthesized that varied between central and peripheral vowels 共the vowels in “beat”-“bit” and “bod”-“bud”兲. Each member of the series was appended to one of four carrier phrases that were spoken in either a “clear” or “reduced” speech style. Participants categorized vowels in these eight contexts. A reliable shift in categorization as a function of speaking style was obtained for three of four phrase sets. This demonstrates that phrase context effects can be obtained with a single talker. However, the directions of the obtained shifts are not reliably predicted on the basis of the speaking style of the talker. Instead, it appears that the effect is determined by an interaction of the average spectrum of the phrase with the target vowel. 关Work supported by NIH-NIDCD.兴 3pSC19. Neural dynamics of speech perception: Phonemic restoration in noise using subsequent context. Sohrob Kazerounian and Stephen Grossberg 共Dept. of Cognit. and Neural Systems, Boston Univ., 677 Beacon St., Boston, MA, 02215, [email protected]兲 Phonemic restoration describes a class of auditory illusions during which broadband noise replacing a deleted phoneme can cause the perceptual restoration of the deleted phoneme. Phonemic restoration exemplifies the brain’s ability to complete and understand speech and language in noisy environments. It also clarifies how both past and future acoustical events can contextually guide completion of a percept that is occluded by noise, and highlights that conscious speech is due to bottom-up and top-down contextual interactions that can operate across hundreds of milliseconds. This work develops a neural model that quantitatively simulates restoration phenomena, including the forward development in time of a conscious speech percept even in cases where future events control how previously presented acoustic events are heard. The model clarifies how acoustic items are stored in short-term working memory, and how they interact reciprocally with unitized representations of item sequences, or list chunks, to generate a resonant wave of activation that embodies the consciously heard percept. Model simulations clarify why the presence of noise is necessary for restoration to occur, and why in the absence of noise a silence gap is perceived. These properties are traced to the brain’s ability to rapidly and stably learn language. 3pSC20. Towards produtive language mapping: A magnetoencephalography study of letter naming. Yang Zhang 共Dept. of Speech-Lang.-Hearing Sci., Univ. of Minnesota, Minneapolis, MN 55455兲, Wenbo Zhang, and Joel Landsteiner 共United Hospital, St. Paul, MN 55102兲 This study aims to examine the sensitivity and specificity of magnetoencephalography 共MEG兲 integrated with magnetic resonance imaging 共MRI兲 for productive language mapping using a simple letter naming task. Six healthy adult volunteers participated after screening for handedness and medical history of speech, language, hearing, and vision. The data were collected using a 148-channel whole-head MEG system 共Magnes WH2500, 4D 2658


Neuroimaging, San Diego兲 at the Magnetic Source Imaging Laboratory in United Hospital, St. Paul. During the recording session in a magnetically shielded room, the subjects were instructed to pay attention to the visual stimuli and articulate the letter from the English alphabet as soon as it was shown on the screen. The averaged epochs and trial-to-trial raw data were analyzed using Brain Electrical Source Analysis 共BESA兲 and BrainVoyager software. Although visual processing of the letters showed similar temporal and spatial activation patterns, letter naming did not show uniform activation patterns in the Broca’s area. Large inter-subject variability was found in terms of superior temporal, inferior parietal, motor, and supplemental motor involvement. The results are discussed with respect to the technical challenges in implementing MEG with millisecond resolution for presurgical productive language mapping and potential risks of sensorimotor and language deficits. 3pSC21. An investigation of brain activation patterns in response to speechreading. Edward T. Auer, Jr. 共Dept. of Speech-Lang.-Hearing, Univ. of Kansas, 1000 Sunnyside Ave., Rm. 3001, Lawrence, KS 66045, auer@ku .edu兲 The ease of recognizing spoken words on the basis of optical input alone, or speechreading, is known to systematically vary as a function of the properties of the stimulus materials. The current study investigated the relationship between cortical responses and the intelligibility of the stimulus materials. Open-set identification performance outside the magnet was used to directly measure the intelligibility of the stimulus materials presented in the magnet as well as participant speechreading ability. fMRI was used to measure cortical response to viewing spoken word stimuli that were predicted to vary in their ease of identification. Videos of spoken words were contrasted with still face images in a block-design fMRI experiment. Blocks containing sets of words predicted to be easy speechread were contrasted with blocks predicted to be difficult to speechread. Preliminary analyses of cortical response to speechreading are consistent with previous studies 关Hall et al., J. Cog. Neuro. 17共6兲, 939–953 共2005兲兴. Furthermore, evidence of increased activation in BA 37 and BA 44 for easy words versus hard words was obtained. These results are consistent with the hypothesis that specific areas are sensitive to the intelligibility of speech read stimuli. 关Work supported by a grant from NIH/NIDCD 共R01DC04856兲.兴 3pSC22. Domain-specific processing of Mandarin tone. Yue Wang 共Dept. of Linguist., Simon Fraser Univ., Burnaby, BC, Canada, V5A 1S6兲, Dawm Behne 共Norwegian Univ. of Sci. and Technol., Trondheim, Norway兲, Angela Cooper, and Jung-yueh Tu 共Simon Fraser Univ., Burnaby, BC, V5A 1S6 Canada兲 Lexical tone has generally been found to be processed predominantly in the left hemisphere. However, given that tone is carried by a syllable or a word with segmental information and distinctive meaning, the processing of tone may not be easily disentangled from that of the phonetic segments and word meaning 关P. Wong, Brain Res. Bull. 59, 83–95 共2002兲兴. Indeed, previous research has not examined the lateralization of tone independent of segmental and lexical semantic information. The present study explores how syllable-based tonal processing in Mandarin Chinese interacts with these different linguistic domains. Using dichotic listening, native Mandarin participants were presented with monosyllabic tonal stimuli constructed with the following different linguistic attributes: 共1兲 real Mandarin words with tonal, segmental phonetic, and lexical semantic information; 共2兲 Mandarin nonwords with tonal and segmental, but no semantic information; 共3兲 nonwords with non-Mandarin segments 共i.e., no native segmental or semantic information兲; and 共4兲 hums of tones 共acoustic pitch information兲 without any segmental or semantic components. Results from these conditions show significant differences in lateralization patterns and are discussed in terms of the integration of acoustic as well as pre- and post-lexical linguistic domains in lexical tone processing. 关Work supported by NSERC.兴 3pSC23. Mismatch negativity reflects the affect of training on speech perception. McNeel Gordon Jantzen and Katherine Cella 共Dept. of Psych., Western Washington Univ., 516 High St., Bellingham, WA 98225兲 An adult’s ability to perceive speech sounds that do not occur in their native language is influenced by the relationship between the new and native language phonology and by the individual’s capacity to perceive acoustic differences. Individual differences are important: even after phonetic train157th Meeting: Acoustical Society of America


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ing, adults with similar language backgrounds exhibit significant individual differences in their ability to learn difficult non-native speech sounds 关Polka 共1991兲; Pruitt, Strange, Polka, & Aguilar 共1990兲兴. Neurophysiologic changes due to learning are also reflected in the mismatch negativity 共MMN兲 response and are indicative of the effects of training 关Naatanen et al. 共1993兲 and Kraus et al. 共1995兲兴. The present experiment included two groups of six normal-hearing monolingual American-English speakers. The experimental group was trained to identify a voiced, unaspirated, dental stop consonant. The control group received no training on the dental. Electrophysiologic responses were measured for both groups in response to the dental and alveolar contrasts using a perceptual mapping procedure. Training improved the experimental group’s ability to perceive the non-native contrast. Training effects were also reflected in the MMN response, as observed by increased duration and decreased onset latency. 3pSC24. The interaction of location with acoustic scale in concurrent speech recognition. David T. Ives, Martin D. Vestergaard, and Roy D. Patterson 共Dept. of Physio., Development and Neurosci., Univ. of Cambridge, Downing St., Cambridge CB2 3EG, UK兲 Location and acoustic scale cues have been shown to have a significant effect on the recognition of speech in multispeaker environments. The interaction of these two cues is less well understood. In this study, subjects are presented with two triplets of concurrent speech syllables with similar temporal envelopes, and asked to recognize a specific target syllable. The task was made more or less difficult by changing the location of the distracting speaker, the scale difference between the two speakers and the relative level of the two speakers. Scale differences were produced by changing the vocal tract length and glottal pulse rate of resynthesized speech: 32 scale differences were used. Location cues were produced by convolving heat-related transfer functions with the stimulus. The target speaker was located directly to the front of the listener and the distracting/masking speaker located from one of five locations 共0, 4, 8, 16, 32 deg兲 on the 0 deg horizontal plane. Target-to-masker ratios of 0 and ⫺6 dB were used. The results show that direction and scale differences cues do interact and this interaction is greatest when directional and speaker scale cues are small. 关Research supported by the U.K. Medical Research Council 共G0500221, G9900369兲.兴 3pSC25. Does training improve consistency of roughness judgments in a matching task? David A. Eddins 共Dept. of Otolaryngol., Univ. of Rochester, 2365 S. Clinton Ave., Rochester, NY 14618, [email protected]兲, Rahul Shrivastav, and Sona A. Patel 共Univ. of Florida, Gainesville, FL 32611兲 Shrivastav et al. 关J. Acoust. Soc. Am. 119共5兲, 3340 共2006兲兴 reported a matching task in which a square wave modulated sawtooth wave 共signal兲 was matched to a series of vowels 共standards兲 to estimate the magnitude of roughness in voices. Results suggested that listeners found it difficult to isolate roughness from other voice quality dimensions such as breathiness. In the present experiment, a brief training session was added prior to the matching task to ensure that listeners were attending to variations in roughness alone. This training consisted of a rank-ordering task in which listeners sorted the 34 test samples of the vowel /a/ in ascending order of roughness. For feedback, these rankings were compared to the rankings made by expert listeners. This criterion was used to ensure that all participants understood the dimension of voice quality under study. Listeners who met a specific eligibility criterion completed a modulation matching task to familiarize them with the matching task itself. Finally, thresholds for the roughness matching task were obtained and compared to thresholds obtained without training. The extent to which task-related training can help listeners make perceptual judgments for specific dimensions of voice quality will be discussed. 3pSC26. Masking release at low sensation levels. Peggy Nelson, Elizabeth Anderson Crump, Yingjiu Nie, and Michelle Hawkinson-Lewis 共Dept. of Speech-Lang.-Hearing Sci., Univ. of Minnesota, 164 Pillsbury Dr. SE, Minneapolis, MN 55455, [email protected]兲 Previous results have shown that listeners with sensorineural hearing loss 共SNHL兲 obtain about half of the masking release of their normalhearing 共NH兲 counterparts. When speech is amplified sufficiently, listeners with SNHL may score like NH listeners in quiet and in steady noise, yet may obtain only half of the expected release from gated noise. We hypoth2659


esize that some of that deficiency may occur because of the impaired listeners’ low speech sensation levels, which results in decreased usefulness of the speech signal in the noise dips. In the current study, NH listeners were tested for their recognition of IEEE sentences in quiet, in steady noise, and in gated noise with the speech presented at varying sensation levels. At low levels 共10–15 dB SL兲, NH listeners scored nearly 100% correct in quiet. In steady noise 共at ⫺10 dB signal-to-noise ratio兲 scores for low-level stimuli were also similar to those obtained at higher SLs. However, at low SLs in gated noise, NH listeners demonstrated less masking release than expected, suggesting that audibility of speech in the dips of noise is important for masking release even when performance in quiet and in steady noise seems optimized. 关Work supported by NIH 5R01DC008306.兴 3pSC27. Listening to natural versus cell phone speech on multiple simultaneous tasks. Srinivasan Nirmal Kumar 共Dept. of Special Educ. and Commun. Disord., Barkley Memorial Ctr., Univ. of Nebraska-Lincoln, Lincoln, NE 68583兲 and Carrell Thomas 共Univ. of Nebraska-Lincoln, Lincoln, NE 68583兲 In typical listening environments, attention is often divided and may have different effects on automatic and controlled processes. Automatic processing is a fast, parallel process not limited by short-term memory, requires little subject effort, but requires extensive consistent training to develop. Controlled processing is a comparatively slow, serial process limited by short-term memory, requires subject effort, and little training to develop 关Schneider and Shiffrin 共1977兲兴. In the present study a methodology was developed to examine effects of controlled and automatic distracters on the perception of distorted speech. Specifically, perception of natural and cell phone speech was investigated while listeners performed simultaneous visual and motor tasks. Young, normal-hearing native speakers of English were presented with SPIN sentences 关Kalikow et al. 共1977兲兴 in a background of multitalker babble 关Bilger et al. 共1984兲兴 using natural and cell phone speech. Prior to the start of the experiment, participants had been trained on visual task using either consistent mapping technique or varied mapping technique. Word recognition scores, pursuit rotor performance, and visual task performance were compared for natural and cell phone speech. The relationship between consistently mapped and variably mapped distracters on perceptual and behavioral performance provides information necessary for more detailed models relevant to real-world environments. 3pSC28. Seeing a speaker’s face helps stream segregation for younger and elderly adults. Alexandra Jesse 共Max Planck Inst. for Psycholinguistics, Wundtlaan 1, 6525 XD Nijmegen, The Netherlands, [email protected]兲 and Esther Janse 共Utrecht Inst. of Linguist. OTS and Max Planck Inst. for Psycholinguistics, Nijmegen, The Netherlands兲 Listening to a speaker while hearing one or more competing speakers in the background can be a challenging task, especially for elderly adults. We show that younger and elderly listeners 共above the age of 65兲 with varying degrees of age-related hearing loss benefit in stream segregation and speech processing from seeing the target speaker talk in addition to hearing an audio mix of a target and a competing speaker. This audiovisual benefit was found for response accuracy and speed in a phoneme monitoring task, where participants indicated by button press the occurrence of given target phonemes in the monitored speech of the target speaker. The audiovisual benefit was larger for younger than for older adults, despite their equivalent performance on auditory-only trials and in an off-line phoneme lip-reading task. Better lip-reading performance, however, predicted a larger audiovisual benefit. The audiovisual benefit was found for both highly visible phonemes 共/p/兲 and poorly visible phonemes 共/k/兲, but was modulated in its size by segmental visibility. The audiovisual benefit therefore arises from local segmental visual information but is also at least partially driven by audiovisual synchrony information that aids in attending to the target speaker. 3pSC29. The eyes’ footprints on the ears: An investigation of short-term speech intelligibility change. Jing Liang 共Dept. of Psych. and Ctr. for Cognit. and Social Neurosci., Univ. of Chicago, 5848 S Univ. Ave., Chicago, IL 60637, [email protected]兲, Steven L. Small, and Howard C. Nusbaum 共Univ. of Chicago, Chicago, IL兲 Although observation of mouth movements improves auditory speech perception, the extent to which visual information aids speech perceptual learning and affects subsequent audio-only speech perception remains 157th Meeting: Acoustical Society of America


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unknown. The current study investigates whether visual speech information, specifically, the synchronized mouth movements of the talking face during training, helps the listener to perceive audio-only speech more effectively after training. An experimental group was trained to recognize audiovisual words presented in noise, while a control group was trained on the same audio speech signal in noise, but with no accompanying mouth movements. The control group provides a baseline estimate of what listeners can learn from the speech signal alone without visual information from the talker’s mouth movements. Both groups were tested on audio-only speech in noise before and after training. All novel words were used in the pretest, training, and posttest. The results demonstrate that visual information aids learning to recognize audio-only speech in noise, suggesting visual information from a talker’s mouth movements during training might change auditory coding of acoustic speech signals. 3pSC30. Effects of audio-visual speech information on recognition memory of spoken words. Kauyumari Sanchez, Rachel M. Miller, and Lawrence D. Rosenblum 共Dept. of Psych., Univ. of California, Riverside, 900 University Ave., Riverside, CA 92521兲 Audio-visual speech has generally been found to contain more usable information than audio-only speech. However, there is conflicting evidence of whether seeing the face of a speaker facilitates memory for spoken words 关e.g., Sheffert et al., Cog. Tech. 8, 42–50 共2003兲兴. To address this issue, three experiments examined whether an audio-visual benefit would be observed on a word recognition task. Experiment 1 compared recognition of spoken words both presented and tested in audio-visual versus audio-only forms. Audio-visual word stimuli were recognized significantly better than audio-only words. Experiment 2 tested whether this benefit was due to the presence of visible articulatory information or simply more information in general. Recognition of words presented 共and tested兲 in audio-only, audiovisual, and audio with accompanying static face image conditions were

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compared. Words presented in audio-visual 共dynamic face兲 form were recognized better than audio-only and audio-static face stimuli. To test whether the benefit of audio-visual presentation was due to encoding, retrieval, or both, Experiment 3 crossed presentation modality 共audio-only versus audiovisual兲 from presentation to test phases. Results showed that the audiovisual form is required in both encoding and retrieval to be beneficial. 3pSC31. Influence of visual speech information on the identification of foreign accented speech. Rebecca K. Reed and Edward T. Auer, Jr 共Dept. of Speech-Lang.-Hearing, Univ. of Kansas, 1000 Sunnyside Ave., Rm. 3001, Lawrence, KS 66045, [email protected]兲 Seeing a native talker’s face improves speech intelligibility in noise for native perceivers. The intelligibility of foreign accented speech 共English spoken by native talkers of Mandarin兲 is more susceptible to the effects of noise than the speech of native talkers. 关Rogers et al., Lang Speech 47共2兲, 139–154 共2004兲兴. The current experiment investigated the influence of seeing the non-native talker’s face on the intelligibility of speech presented in noise. Ten talkers 共nine non-native and one native兲 were recorded producing 155 sentences each. Talker-specific speech shaped noise was mixed with the audio of the sentences. Eighty-one native perceivers of English 共nine per non-native talker兲 responded to 20 sentences spoken by the native talker and 28 by the non-native talker in each condition 共audio-alone, visual-alone, audiovisual兲. Open set identification responses were scored as percent words correct for each condition and talker. Preliminary analyses demonstrate that although seeing the non-native talker increases intelligibility, the gain is significantly reduced compared to the native talker. Results will be discussed in terms of potential sources of the audiovisual gain. These sources are hypothesized to be differentially sensitive to the distortions arising in non-native speech. 关Work supported in part by NIH/NIDCD DC04856 and the University of Kansas, UGRA.兴



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PAVILION WEST, 1:00 TO 2:05 P.M. Session 3pUW

Underwater Acoustics and Acoustical Oceanography: Physics-Based Undersea Clutter Model Verification and Validation II Juan I. Arvelo, Cochair Applied Physics Lab., Johns Hopkins Univ., Laurel, MD 20723-6099 Kenneth G. Foote, Cochair Woods Hole Oceanographic Inst., Woods Hole, MA 02543 Timothy K. Stanton, Cochair Dept. of Applied Ocean Physics and Engineering, Woods Hole Oceanographic Inst., Woods Hole, MA 02543 Contributed Paper from weak undulations in the seabed will be presented. Existing Fresnel–Kirchhoff theory for monostatic, vertical incidence on a two-dimensional surface is adapted to demonstrate the behavior of the intensity’s scintillation index in bistatic geometry. In addition, using a simulation of bistatic geometry and a one-dimensional surface, the intensity statistics are extended to include autocorrelation function and probability distribution. Bistatic geometries include source and receiver moving with constant separation, and moving source with fixed receiver. Fairly modest vertical undulations can result in significant fluctuation due to reflection focusing with scintillation indices possibly greater than unity.

1:00 3pUW1. Propagation focusing in the context of clutter statistics. Chris Harrison 共NURC, Viale S. Bartolomeo, 400, 19126 La Spezia, Italy, harrison @nurc.nato.int兲 Fluctuations in reverberation 共clutter兲 from scatterers at long range in shallow water can be affected by many mechanisms. Their statistics, in particular the scintillation index, depend not only on the statistics of the scatterers 共their physical distribution, shape, orientation, etc.兲 but on the outward and return propagation paths. Focusing effects due to forward scattering

Invited Paper 1:15 3pUW2. Estimating higher moments of shallow water reverbation for non-Gaussian scatterer distributions. Kevin D. LePage 共NATO Undersea Res. Ctr., Viale San Bartolomeo 400, 19126 La Spezia, Italy兲 Reverberation is described as a random process by which deterministic propagation components weight and sum scattering amplitudes over the sonar footprint. A method of estimating the second, third, and fourth monents of the scattered field pressure is described for scatterers which have a Chi Squared model for the amplitude pdf. Comparison of theoretical estimates of the fourth moment to Monte Carlo estimates of the same quantity obtained using a NRL 2-way parabolic equation PERM show good agreement. 关Work supported by ONR.兴

Contributed Papers 1:35 3pUW3. Measurement and modeling of broadband Bragg scattering from a sinusoidal surface. Dajun Tang and Darrell R. Jackson 共Appl. Phys. Lab., Univ. of Washington, 1013 NE 40th St., Seattle, WA 98105, djtang @apl.washington.edu兲 While the mechanism of Bragg scattering is well known, most experimental work has been concentrated in the area of narrow band sound sources and in the far-field. Motivated by underwater detection problems in the presence of sediment ripple fields, we report laboratory measurements of broadband sound scattering from a sinusoidal surface machined on a polyurethane board. The surface has a wavelength of 8 mm and peak-to-peak height of 2 mm. Coherently scattered sound data were taken in near-field geometries and in the frequency band of 150–400 kHz. The measurement geometry is such that a broad range of Bragg angles corresponding to the frequency band are covered. We observe that the scattered sound demonstrates a down chirp time dependence when the incident sound is a short pulse. Models based on first order perturbation theory were developed which explain the observed scattered sound in both magnitude and phase. In addition, we also measured second order Bragg scattering. This motivates modeling efforts on higher order Bragg scatter. 关Work supported by ONR.兴 2661


1:50 3pUW4. Validation of a physical model for surface clutter. Trudy L. Philip, Bruce K. Newhall, and Juan I. Arvelo 共Johns Hopkins Univ. Appl. Phys. Lab., 11100 Johns Hopkins Rd., MS 8-220, Laurel, MD 20723兲 There is a strong need to more accurately represent active sonar system false contacts in various environments and conditions for the purpose of active acoustic simulation and synthetic training. A computationally viable approach for the generation of physics-based false contacts in a raw beamformed time series that can be injected into a sonar processor was previously developed for bottom clutter. That model is now extended for clutter due to rough ocean surface scattering, and is compared with ASIAEX01 data. Considerations in extending the existing model include: characterizing appropriate statistics of the rough surface, adding surface scattering clutter to the sonar model, evaluating the realism of the simulation, and evaluating the computational burden 共for real-time trainers兲. The output of the simulation was analyzed for those considerations and then compared to the data. The use of a vertical line array allowed physical mechanisms in the data to be isolated, and their clutter data statistics separately determined. After comparing data statistics to predictions, the need for additional modeled clutter mechanisms was assessed. This effort was conducted under the auspices of the Undersea Warfare Business Area Independent Research and Development program of the Johns Hopkins University Applied Physics Laboratory. 157th Meeting: Acoustical Society of America


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GRAND BALLROOM, 3:30 TO 5:15 P.M.

Plenary Session and Awards Ceremony Mark F. Hamilton, Chair President, Acoustical Society of America

Business Meeting of the Acoustical Society of America

Presentation of Certificates to New Fellows Russell E. Berger, II Suzanne E. Boyce Douglas S. Brungart Richard S. McGowan Luc Mongeau Patrick W. Moore Trevor R. T. Nightingale

D. Lloyd Rice Christine H. Shadle Martin Siderius Aaron M. Thode Doug H. Whalen Lisa M. Zurk

Presentation of Acoustical Society Awards

Medwin Prize in Acoustical Oceanography to Martin Siderius

R. Bruce Lindsay Award to Kelly J. Benoit Bird

2008 Silver Medal in Speech Communication to Winifred Strange

Gold Medal to Thomas D. Rossing

Presentation of Vice President’s Gavel

Presentation of President’s Tuning Fork

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