âthat is, a reduced ability to hear words correctlyâcan lead to avoidance of social settings, ..... Journal of Speech and Hearing Disorders, 17, 321â337. Humes ...
Effect of Computerized Auditory Training on Speech Perception of Adults With Hearing Impairment Rachel Pizarek Weill Cornell Medical College New York, New York Disclosure: Financial: Rachel Pizarek is an audiologist at Weill Cornell Medical College. Nonfinancial: Rachel Pizarek has non nonfinancial information to disclose.
Valeriy Shafiro Patricia McCarthy Rush University Chicago, Illinois Disclosure: Financial: Valeriy Shafiro is a researcher and associate professor at Rush University. Patricia McCarthy is a professor at Rush University. Nonfinancial: Rachel Pizarek has non nonfinancial information to disclose. Patricia McCarthy and Valeriy Shafiro have previously published in this topic area.
Abstract Computerized auditory training (CAT) is a convenient, low-cost approach to improving communication of individuals with hearing loss or other communicative disorders. A number of CAT programs are being marketed to patients and audiologists. The present literature review is an examination of evidence for the effectiveness of CAT in improving speech perception in adults with hearing impairments. Six current CAT programs, used in 9 published studies, were reviewed. In all 9 studies, some benefit of CAT for speech perception was demonstrated. Although these results are encouraging, the overall quality of available evidence remains low, and many programs currently on the market have not yet been evaluated. Thus, caution is needed when selecting CAT programs for specific patients. It is hoped that future researchers will (a) examine a greater number of CAT programs using more rigorous experimental designs, (b) determine which program features and training regimens are most effective, and (c) indicate which patients may benefit from CAT the most. Most adults, as they age, begin experiencing some difficulties with speech perception, especially in noisy environments. In fact, difficulties with speech perception are among the most common complaints of older adults during audiology visits. Although hearing loss, which generally accompanies aging, is the major cause of these difficulties, recent work has also shown important influences of cognitive functions such as memory and attention (Humes & Dubno, 2010; Lunner & Sundewall-Thoren, 2007; Pichora-Fuller, 2003; Pichora-Fuller & Levitt, 2012; Ronnberg, Rudner, Foo, & Lunner, 2008). A decline in speech perception accuracy —that is, a reduced ability to hear words correctly—can lead to avoidance of social settings, loss of work productivity, isolation, negative health behaviors, and cognitive decline (Lin et al., 2011). Amplification with hearing aids (HA) or, in more severe cases, cochlear implantation (CI), is the most common approach to addressing the communicative problems of audiology
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patients. Unfortunately, electronic sensory aids improve patients’ hearing ability optimally after a period of perceptual adaptation or adjustment and cannot completely restore normal hearing. Auditory training has been recommended and used to maximize the communicative benefits of amplification and improve patients’ satisfaction with their devices (Sweetow & HendersonSabes, 2004). Auditory training programs can play a significant role in promoting adjustment to the new device, and may facilitate neuroplastic changes in response to modified auditory input. Auditory training can be defined as the “use of instruction, drill, or practice designed to increase the amount of information that hearing contributes to a person’s total perception” (Blamey & Alcantara, 1994, p. 163). Auditory training has existed at least since World War II and is continually evolving. Auditory training may include tasks of detection, discrimination, identification, and comprehension of various forms of acoustic information, most commonly speech, but sometimes music and psychoacoustic stimuli (Alpiner & McCarthy, 2009). This type of training can be used during the period of adjustment to hearing aids and can be focused on listening retraining or analytic listening, or on increasing patients’ tolerance of loudness. Training can be instrumental in involving patients in their adjustment period by teaching them the difference between hearing and listening, building their confidence, and providing communication strategies or communication tips. Such training can be instrumental in reducing return visits as well as the return of hearing aids for credit (Sweetow & HendersonSabes, 2006). Often, this type of training is performed by a skilled clinician as part of the patient’s overall audiologic rehabilitation, including individual counseling and group rehabilitation. Since the growth and accessibility of powerful personal computers, a number of computerized auditory training (CAT) programs have been developed. Such programs offer patients a low-cost, low-risk opportunity to improve their communication skills from the comfort of their home. The CAT programs can be used either independently, or with assistance from an audiologist or another hearing adult. Notwithstanding marketing pitches made by CAT program manufacturers, however, many programs have not undergone a rigorous independent evaluation to determine their benefits for those with hearing impairment. The success of auditory training is premised on the ability of the central auditory nervous system to change itself in order to accommodate the learning of new response patterns (i.e., neural plasticity). Although it is most plastic in childhood, evidence suggests that, with appropriate stimulation, the auditory nervous system is capable of robust (meaning resistant to degradation) neural plasticity in older adults as well (Anderson, White-Schwoch, Parbery-Clark, & Kraus, 2013; Song, Skoe, Wong, & Kraus, 2008). Sweetow and Henderson-Sabes (2004) observe “[…] recent discoveries in neuroscience suggest that training may enhance auditory skills and even bring about changes in the central auditory system […]” (p. 32). After an extended period of reduced or no auditory stimulation with resulting neural atrophy, patients’ memory representations for many common speech and nonspeech environmental sounds can decay. As a result, patients may not recognize some sounds that have been restored to audibility through amplification or cochlear implantation. Even when memory representations of specific sounds remain robust, perceptually salient acoustic cues in acoustic input may become distorted during signal processing. This processing is performed by electronic sensory aids, so a period of perceptual adaptation to listening with a device becomes necessary. For adult patients, a number of CAT programs have been designed specifically to enhance this “re-learning” to changed input and to optimize their listening skills. In addition to training patients to detect low-level phonetic and acoustic features, some training programs also focus on enhancing cognitive processes that can help to improve topdown information processing aspects of auditory perception. These cognitive processes, including short-term or working memory, attention, and speed of processing, have been shown
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to influence speech perception abilities of adults with hearing impairment (Lunner, 2003; Pichora-Fuller & Levitt, 2012). Several mechanisms in the cerebral cortex may facilitate speech perception in noise, potentially rendering training programs with a cognitive focus useful for older adults with hearing impairment (Anderson et al., 2013; Wong, Ettlinger, Sheppard, Gunasekera, & Dhar, 2010). Auditory training programs, including those focusing on cognitive processes, have also been shown to benefit children with learning disabilities and those who use CIs (Hayes, Warrier, Nicol, Zecker, & Kraus, 2003; Kronenberger, Pisoni, Henning, Colson, & Hazzard, 2011). On the other hand, a recent systematic review of auditory training programs for adults with hearing loss has concluded that the evidence for their efficacy “is not robust and cannot be reliably used to guide intervention at this time” (Henshaw & Ferguson, 2013). The authors further note that the quality of evidence found even in peer-reviewed studies of CAT remains low, making it difficult to assess its potential. Henshaw and Ferguson (2013) examined the results from 13 studies of CAT that were ranked in terms of levels of evidence by study quality score (Group, 2004). For study selection, the authors applied a rigorous set of criteria using Participant, Control, Intervention, and Study Design Strategy (PICOS; Moher, Liberati, Tetzlaff & Altman, 2009). Although the study quality varied considerably, all studies were published in peer-reviewed journals. In addition to speech perception outcomes, Henshaw and Ferguson also examined other outcomes of auditory training, including self-reported hearing abilities and changes in cognition. In the majority of the studies, training was performed in the laboratory with CAT programs that were developed “in-house” and were not available to the general public thereby limiting the clinical application of these findings. Currently, a variety of CAT programs are available to patients with hearing impairment (See Appendix A). Some focus on specific aspects of auditory speech perception, whereas others offer various types of perceptual and cognitive training with some methodological overlap across programs. Some are older, better-known programs that have been described in peerreviewed research (e.g., Listening And Communication Enhancement (LACE; Sweetow & Henderson-Sabes, 2004, 2006); peer-reviewed evidence for other programs (e.g., eARena by Siemens), however, is currently lacking. The goals of the present study were twofold: (a) to examine the effectiveness of CAT programs on speech perception abilities of adults with hearing impairments and (b) to familiarize clinicians with specific, currently available CAT programs. Published studies meeting specific inclusion criteria, described below, were reviewed (See Appendix B). Unlike the recent CAT review conducted by Henshaw & Ferguson (2013), the present investigation included only studies based on CAT programs that are readily available to the public (either at a cost or free of charge). Because only a minority of such programs has been evaluated in peerreviewed research, all published experimental studies in which specific CAT programs were evaluated were included in the current study if other inclusion criteria were also met. Although the peer-review process represents a commonly accepted quality benchmark, a broader scope was deemed appropriate for this preliminary stage of CAT reviews to permit identification of potentially efficacious approaches. It is hoped, furthermore, that this broader inclusion criterion will stimulate more rigorous future investigations, while also raising awareness about the quality of evidence (or its lack thereof) for existing CAT programs. With the development of many different types of CAT programs, information is needed to determine which programs are best for which individuals. This review was performed to help clinicians decide which CAT approach is most appropriate for their patients.
Method Study Inclusion Criteria
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Several inclusion criteria were applied in selecting CAT programs for this review. First, studies of CAT approaches that can be used independently by patients were considered. Although an audiologist or another person can still provide assistance in administering these CAT programs (e.g., Ingvalson, Lee, Fiebig, & Wong, 2013), such assistance is not a built-in feature or a prerequisite for their use. Participants’ age and CAT design were also factors in the selection process. Finally, studies published between 2000 and 2013 were considered. Search Terms Several methods were utilized in obtaining articles for this review of CAT programs. Database searches were one such method and included CINAHL (Cumulative Index to Nursing and Allied Health Literature), PubMed, and Google Scholar. Publications in English between the years 2000 and 2013 were considered. Articles were retrieved from various databases using combinations of the keywords “auditory training,” “computerized auditory programs,” “computerized rehabilitation,” “auditory rehabilitation,” “computerized communication enhancement”, “speech perception training”, and the names of known programs (e.g., eARena, LACE, Computer Assisted Speech Training [CAST], etc.). Key words were always combined so that only papers with adult subjects with hearing loss would be identified. Additional articles were identified by reviewing reference sections of selected articles and through personal communication with other researchers. In addition, one audiologic rehabilitation textbook (Montano & Spitzer, 2009) was searched to identify references that met the search criteria. Of the resulting articles, the abstracts were reviewed, the inclusion criteria applied, and the full article reviewed. Nine articles, summarized in Appendix B were included in the present review. Study Goals Each of the nine selected studies used a specific CAT program to examine changes in speech perception abilities of hearing impaired adults following training. The studies differed, however, in terms of training stimuli (e.g., speech, music, or audio vs. audiovisual), training regimen (duration, frequency), and context (e.g., lab- or clinic-based vs. home). For example, Fu and Galvin (2007) examined the effectiveness of Computer-Assisted Speech Training (CAST) on speech as well as music perception in CI users. In another study, Oba, Fu, & Galvin (2011) examined generalization of training effects for speech recognition in noise in CI users. Barcroft et al. (2011) compared the effectiveness of training with single vs. multiple talker speech stimuli. In two studies, Sweetow & Henderson-Sabes (2004, 2006) assessed the benefits of Listening and Communication Enhancement (LACE) on speech perception of hearing aid users. Levitt, Oden, Simon, Noack, & Lotze (2011) evaluated the effectiveness of lip reading training on speech perception in noise using a unique crossword like training format. Visual and auditory cuing integrated into the Seeing and Hearing Speech program were used by Ingvalson et al. (2013) to investigate whether speech recognition in noise improves following a short-term training regimen. Finally, Zhang, Dorman, Fu, & Spahr (2012) examined the effect of training in patients with bimodal stimulation. Sample Size The number of participants included in each study ranged from five to 69, with six of the nine studies having 10 participants or less. There were a total of 212 participants across the nine studies reviewed. In one study, Sweetow and Henderson-Sabes (2004) used eight experienced hearing aid users; in their subsequent study (2006), they included 65 adults with hearing impairment. Oba et al. (2011) used 10 postlingually deafened CI users; Miller et al. (2008) investigated 28 adults with hearing impairment. There were 10 CI patients in Fu and Galvin (2007) and 10 HA users in Levitt et al. (2011). Five deafened adults took part in the Ingvalson et al. (2013) study, and seven deafened bimodal CI and HA users took part in the Zhang et al. (2012) study. Finally, there were 69 current HA users in the Barcroft et al. (2011) study. Study Design
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The design of the nine studies in this review varied considerably with respect to: •
the type of training (e.g., audio vs. audiovisual);
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the specific CAT program used;
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where training was conducted (i.e., at home, in the clinic, or in a laboratory);
•
the frequency and duration of training
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the types of speech outcome measures
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the degree of control for extraneous effects
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the level of patient experience
•
the type of amplification used
Details of each study’s design are described below. Sweetow and Henderson-Sabes' (2004) investigation of the efficacy of LACE included an experimental treatment group and a control group with four participants each. Training consisted of one 30 minute task per day, five days a week for 4 weeks. The training stimuli included 1500 digitally recorded sentences in noise. The signal-to-noise ratio (SNR) varied pseudo-randomly from -5 to +3 dB. Outcome measures included the Hearing in Noise Test (HINT; Nilsson, Soli, & Sullivan, 1994) sentences and the Speech In Noise (QuickSIN) test (Niquette, Gudmundsen, & Killion, 2001). In a follow-up study that included a greater number of participants (N=65), Sweetow and Henderson-Sabes (2006) used a similar between subject design with repeated, pre-test and post-test, measures. Two thousand sentences from LACE software were used as stimuli. Each participant was asked to choose a subject topic (e.g., money matters, exercise, health, or potpourri) and was trained using sentences relevant to that topic. Stimuli were presented in the soundfield at the participant’s most comfortable level (MCL), based on a calibrated measure. Outcome measures were the Hearing Handicap Inventory for Adults/Elderly (HHIA/E; Newman, Weinstein, Jacobsen, & Hug, 1990; Ventry & Weinstein, 1982), the Communication Scale for Older Adults (CSOA-s= strategies subset; Kaplan, Bally, Brandt, Busacco, & Pray, 1997), the HINT, and the QuickSIN. The experimental group was tested four times: within 2 days prior to training (baseline), at 2 weeks into the training (mid-training), at the end of the 4 week training program (post-training), and at 8 weeks (4 weeks post-training). The control group was tested at baseline and 4 weeks later. Next, in a cross-over design, the participants in the initial control group received training and were again tested at 2 weeks into the training (mid-training), at the end of the 4-week training program (immediately posttraining), and again at 8 weeks (4 weeks post-training). Fu and Galvin (2007) tested a single group of 10 CI listeners using CAST. Participants trained at home 1 hour per day, 5 days per week, for a period of 1 month or longer. They returned to the laboratory every 2 weeks for retesting using the same test battery that included HINT sentence recognition thresholds in steady and speech-shaped noise, the Institute of Electrical and Electronics Engineers sentences (IEEE, 1969) recognition in quiet, multitalker vowel recognition in quiet, and multitalker consonant recognition in quiet. Oba et al. (2011) tested 10 deafened patients with CIs with no separate control group. Before training was begun, recognition of digits, HINT, and IEEE sentences were repeatedly measured to establish a stable estimate of baseline performance. Participants trained at home on personal computers using CAST for 30 minutes per day, 5 days a week, for 4 weeks, for a total of 10 hours of training. During training, SNR was adjusted according to subject performance. Recognition of digits, HINT sentences, and IEEE sentences in steady-state noise and speech babble was remeasured after the second and fourth week of training. Training was
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stopped after the fourth week, and subjects returned to the laboratory 1 month later for followup testing. Miller et al. (2008) trained 12 patients with HAs and six with CIs in a single experimental group using SPATS as the intervention. Training was organized as a “training rotation” with a goal to complete 12 rotations. Each rotation included training on identification of (a) syllable onsets and nuclei in quiet and in noise and (b) short sentences at signal-tobabble ratios that were adapted for each participant’s performance. The sentence module consisted of 1000 recorded sentences with simple syntax and four to seven common everyday words. During training, sentences were presented at SNR levels that varied from +15 to −15 dB. Outcome measures for pre- and post-tests were the HINT, CNC tests, W22 tests (Hirsh et al., 1952), the Connected Speech Test (CST; Cox, Alexander, & Gilmore, 1987), parts of the Speech, Spatial and Qualities of Hearing Scale (SSQ; Gatehouse & Noble, 2004), and a specially designed SPATS questionnaire. Levitt et al. (2011) trained 10 HA users (nine experienced and one a new user) using Read My Quips. Training was conducted over a 3 week period at participants’ homes on a loaner laptop for approximately 30 minutes a day. The outcome measure was the SNR at which the IEEE sentences were identified with 50% accuracy. In the Barcroft et al. study (2011), patients with HAs underwent 6 weeks (12 lessons) of training using the I Hear What You Mean program. One group of patients received training with single talker speech materials, while the other received training with speech materials from six talkers. Pre- and post-test outcome measures included the Iowa Consonant Test (Tyler, Preece, & Tye-Murray, 1986), Build-A-Sentence Test (Tye-Murray et al., 2008) and the Four-Choice Discrimination Test (Erber, 1982). The latter was the only test for which results were reported because it was the only measure that allowed for a direct comparison between groups in terms of the single vs. multiple talker training materials. The test was given in a four-alternative forced choice picture-based response format, and it consisted of 144 word pairs presented in a 4-talker babble at 2dB signal-to-babble ratio. Ingvalson et al. (2013) trained a single group of five post-lingually deafened adult CI recipients using the Seeing and Hearing Speech program, which, per its name, includes both auditory and visual cues. Training, conducted with an experimenter’s guidance, included four 1 hour sessions focusing on vowel and consonant identification in word, phrase, and sentence context at variable SNRs. Outcome measures for speech in noise assessment were the QuickSIN, HINT, and SSQ. All outcome measures were administered before the training began, at the end of the last training session and once again 4 days after training. Zhang et al. (2012) trained seven deafened adults who were fitted with bimodal arrangements (i.e., one cochlear implant, one hearing aid) using the CAST: Sound Express program that focuses on phoneme-contrast discrimination with the SNR varied adaptively based on performance accuracy. Participants were trained with acoustic stimulation alone, electric stimulation alone, and combined electric and acoustic stimulation conditions. Training took place at home for 1 hour per day, 5 days a week, for 4 weeks with both their CI and HA devices. With a single group repeated measures design performance was evaluated four times: before, during, immediately after training, and 1 month after the training period ended. Performance was evaluated with closed-set vowel and consonant tests, and tests of talker gender and emotion identification. Two open-set tests, CNC monosyllabic words and AzBio sentences (Spahr et al., 2012) were also used to examine performance.
Results Due to the small sample size in their early study, Sweetow and Henderson-Sabes (2004) did not perform a statistical analysis; nonetheless, they did observe improvements in speech recognition in noise for three out of the four subjects in the experimental group following
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training. In their subsequent study, Sweetow and Henderson-Sabes (2006) observed small training effects among participants in the experimental group on nearly all outcome measures, with the exception of the HINT and CSOA-s. No improvements were observed for the control group. Effect sizes for the experimental group were 0.4 on the HHIE and CSOA-s, 0.31 for the QuickSIN at 45 dB HL, and 0.23 for the QuickSIN at 70 dB HL. For all of the off-task preversus post-training measures, the effect sizes exceeded 0.2. The average HHIE/A score decreased following training indicating a decrease in handicap. Fu and Galvin (2007) found that both vowel and consonant recognition significantly improved for all participants after training. The mean vowel recognition significantly improved by 15.8 percentage points, and the mean consonant recognition significantly improved by 13.5 percentage points. The researchers observed considerable intersubject variability in terms of the amount of improvement as well as in the time course of improvement. Performance for some participants significantly improved after only a few hours of training, whereas others improved only after longer periods of training. Oba et al. (2011) found that the average performance under both steady state noise and speech babble in moderate SNRs improved for almost all participants after training. The mean performance in steady state noise improved by 12.8 percentage points, and the mean performance under speech babble improved by 28.3 percentage points. Post-training performance (4 weeks after training was begun) and follow-up performance (4 weeks after training was stopped) were significantly better than pretraining performance for all test measures. There was no significant difference between post-training and follow-up measures, suggesting that the training benefits were largely retained one month after training was stopped. Results of Miller et al. (2008) showed that performance for the group that received training improved for most outcome measures (i.e., HINT, CNC tests, W22 tests, the CST, the portions of the SSQ that were administered, and the SPATS questionnaire) in the 17.6–25 percentage point range, while the performance of control participants decreased or remained unchanged. Levitt et al. (2011) observed a statistically significant decrease in the SNR at which the IEEE sentences were recognized 50% of the time for seven of the ten participants. The biggest SNR decrease of 15.5 dB was demonstrated by the new HA user who, concurrently with training, was undergoing a period of adaptation to the amplification device. The average SNR improvement for the experienced HA users was 2.8 dB. Those participants who spent more time using the training program demonstrated greater changes in their SNR scores. Results of the Barcroft et al. (2011) study showed an overall improvement of 13.7 percentage points in the Four-Choice Discrimination test averaged across the single- and multi-talker training groups. Both groups achieved significant word discrimination gains with those trained with multiple talkers showing a greater improvement, which, however, was not significantly different from those in the single-talker group. Ingvalson et al. (2013) reported a significant improvement in HINT key word identification scores at +15 dB SNR and a significant reduction in QuickSIN SNR at both posttest sessions. Thus, the results indicate that speech-in-noise perception improved as a function of the training program and that improvement was maintained for at least 4 days without additional intervention. However, there was no significant change in SSQ scores, possibly indicating the need for a longer training period for the positive effects of training to be detectable in listeners’ daily lives. Zhang et al. (2012) showed that following training, there was a significant improvement in vowel, consonant, and CNC word identification in the electric (E) and combined electric and acoustic stimulation (EAS) conditions. The improvement in the E condition was equivalent to
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that in the EAS condition. Improved performance was retained one month post-training. Speech-recognition performance improved for six of seven subjects. Pitch-related performance, however, did not improve for any of the seven subjects, and one subject showed no improvement on any test measure.
Discussion All nine studies included in the present review demonstrated that computerized auditory training appears to improve speech perception accuracy in adults with hearing impairment. Significant training effects often remained after the training had stopped. These results are in good agreement with those of Henshaw and Ferguson (2013) despite the differences in article selection criteria and other study methods. The convergence of research findings is encouraging because CAT provides a low-cost, low-risk and convenient approach to improving the communication abilities of individuals with hearing difficulties. As also noted by Henshaw and Ferguson (2013), however, the design of the reviewed studies varied considerably and the overall quality of the evidence remains low. Thus, these conclusions need to be viewed with caution until higher quality evidence becomes available to support the development of clinical guidelines and best practices for CAT use. Six CAT programs (or program components) were used in the nine studies reviewed herein. A much larger number of training programs exist (see Appendix A), however, and many are being marketed without evaluative research provided to the general public. Thus, as new programs appear on the market, there is often insufficient evidence to judge their effectiveness. This problem is partially resolved if a newer program contains components of older programs that have undergone prior testing. Such is the case with Angel Sound and Sound and Way Beyond, which incorporate many of the components of CAST. Fortunately, some programs enable user data to be accumulated quickly and easily, serving as a basis for the development of local norms thereby optimizing the opportunity for clinical evaluation and program development. When there is a lack of evidence for a specific CAT program’s effectiveness, one should examine the available information regarding its development to determine if the program or any of its components have been tested and whether or not the results have been published. Other factors to consider are the cost, which can range from completely free (e.g., Angel Sound) to several hundred dollars (e.g., Sound and Way Beyond) even though they include similarly developed program components and features. As with any computer program, questions of user friendliness, entertainment value, and ease of administration are also important variables that are likely to affect adherence and the ultimate effectiveness of specific training programs. Knowledgeable computer users may be expected to be more receptive to CAT applications as a therapeutic intervention, although they may also expect more sophisticated user control options. The lack of compelling evidence for many auditory training programs may explain why only a small portion (about 10%) of audiologists offer them to their patients with hearing impairment (Sweetow & Henderson-Sabes, 2010). With increased empirical evidence, audiologists may feel more comfortable recommending CAT programs. Acceptance of these programs is contingent upon patient motivation and adherence to CAT regimens. As in other health care areas in which computer-based behavioral intervention is often applied, (e.g., weight-control, smoking, and alcohol cessation), patient motivation and adherence may be enhanced with greater attention to program design. For many patients, monotonous single word discrimination tasks performed over the course of several weeks or months can seem tedious and boring thereby limiting adherence to the regimen and the potential benefits of training. Programs that pique patients’ interest in more meaningful ways may lead to greater patient satisfaction and program adherence (Levitt et al., 2011; Tye-Murray
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et al., 2012). Finally, as the population ages, the acceptance of CAT programs by patients may increase as a greater number of individuals with hearing loss will be those who have already embraced computers in all aspects of their everyday life. The CAT programs available to patients today differ greatly in terms of training materials and the training protocols. Although some incorporate visual lipreading cues (e.g., Read My Quips and Seeing and Hearing Speech) others focus mostly on auditory cues. Some primarily use bottom-up phoneme discrimination training; others incorporate auditory working memory training as well as more meaningful spoken phrases that enhance the use of contextual semantic cues and are more entertaining to patients (Pichora-Fuller and Levitt, 2012). The paucity of available research and the heterogeneity of training designs, however, prevents conclusive statements regarding the most effective approaches to CAT and which are most effective. Similarly, the characteristics of patients who are most likely to benefit from CAT remain unknown. Evidence to date suggests that patients who score lower at baseline and who practice more hours will show greater improvement on outcome measures. Nonetheless, how different kinds of hearing loss, intervention devices, or demographic factors affect the success of CAT is still unknown. The present review focused on the effects of CAT on speech perception, however, potential benefits of CAT can also be considered in broader contexts of human communication, cognitive functioning, and well-being. Moreover, it is also important to consider how the small gains seen on specific clinical measures might translate into real-life communication benefits. Sweetow and Palmer (2005) found limited, albeit positive, evidence of improvements in overall communication skills following CAT. More recently, Henshaw and Ferguson’s (2013) systematic review of the literature documented improvements in cognition and self-reported hearing abilities in addition to those in speech perception. These authors also noted, however, that the improvements were generally small and not robust. Although their conclusion is potentially confounded by the lack of high quality evidence available from small scale studies, it is worth noting that the positive trends among these studies are consistent. Indeed, the benefits of CAT may not be limited to improvements in speech perception, but may also include more efficient adjustment to hearing aids, improved communication confidence and more effective communication strategies (Sweetow & Henderson-Sabes, 2006). Computerized training may be used as part of broader programs of audiologic rehabilitation including group and counseling approaches, further enhancing the benefits of audiologic rehabilitation for patients. Some suggest that CAT programs may be of benefit to individuals who do not demonstrate a clinical hearing loss. For example, in one study, Anderson et al. (2013) trained older adults with age-appropriate hearing thresholds using the cognitiveauditory Brain FitnessTM program (Smith et al., 2009). The authors found that participants improved in both objective (i.e., brainstem timing) as well as subjective measures (speech-innoise perception, short-term memory and processing speech) as a function of CAT. These results indicate that CAT may be an effective enhancement to communication ability even prior to the onset of hearing loss.
Summary and Conclusions A review of nine studies in which six different publicly available computerized auditory training programs were evaluated was conducted to examine the programs’ effectiveness for improving speech perception abilities in adults with hearing impairment. The results indicate that the LACE, SPATS, Read My Quips, I Hear What You Mean, Seeing and Hearing Speech, and CAST (Sound Express) programs produced positive changes in speech perception. Given the limited sample size and other design issues with some of these studies, in addition to the fact that not all were published in peer-reviewed journals, the quality of evidence regarding CAT programs remains guarded. Thus, although the results of these studies are encouraging, caution is needed when selecting and recommending CAT programs to patients. Factors such
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as demonstrated program effectiveness, cost, effort, patient motivation, perceived benefits, and familiarity with computer use should be considered. Future research is needed to provide rigorous evaluations of CAT programs that are on the market, determine the characteristics of patients who are most likely to benefit from CAT, and suggest improvements in CAT program design that can make them most effective in ameliorating the impact of hearing loss on communication. Comments/questions about this article? Visit SIG 7’s ASHA Community and join the discussion!
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Appendix A. Available Computerized Auditory Training Programs.
Program Name
Manufacturer
Populati on
Training Stimuli
Price
PeerReviewed
Baldi
Psyentific Mind
All
Speechreading training by a talking head that can speed controlled. Articulators can be made visible.
$1.99 for the app on any Apple device
No
TigerSpeech Technology
CI, but can be used with other hearing impairme nts
Interactive computer training with vowel, consonant, sentence, telephone, and music stimuli.
Core software in Sound and WAY Beyond, Angel Sound, and Sound Express
Yes
Sound Express*
TigerSpeech Technology (for research)
CI
As above
Free
Yes
Sound and Way Beyond*
Cochlear Americas
CI
As above
$99.00/$290 .00
Yes
TigerSpeech Technology
All
As above but with additional training modules added
Free
Yes
Arthur Boothroyd
HA/CI
Tutorials composed of testing the perception of sentences and single words, different tasks, and nonsense syllables, words and phrases.
Free
Yes
http://psyentificmind.com/p honics-with-baldi Computer Assisted Speech Training (CAST)* http://www.tigerspeech.com/ tst_cast.html
http://hope.cochlearamericas .com/sound-way-beyond Angel Sound* http://angelsound.tigerspeec h.com/ CASPERsent http://wwwrohan.sdsu.edu/~boothro/na s/
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Cognition 1 (CAT)
Klaus Marker
Cognitive
64 programs for testing and training, varies on visual motor, reaction, comprehension, vigilance, memory, language, intellectual and professional skills. Tasks can be edited and expanded.
€160.00450.00
Yes
Pearson
Cognitive
Rigorous program designed to improve working memory through intensive and systematic training.
varies by practice
Yes
Siemens
HA
Loudness scales, everyday sounds, listening, word recognition, sound discrimination, and speech in noise training.
$15.00 but can vary by practice
No
Scientific Learning Company
Cognitive
Designed to facilitate speech perception and word discrimination abilities
varies by practice
Yes
Brain Fitness Program, Posit Science
Cognitive
Designed to improve the function of the auditory system through intensive brain plasticity–based learning
$395-495.00
Yes
Robert Sweetow
HA
Degraded Speech, Cognition, Interactive Communication
$59.00$149.00
Yes
http://www.markersoftware.c om/D/workshop.htm
CogMed http://www.cogmed.com/ eARena https://w1.hearing.siemens.c om/_resourcesre/sicherungskasten/18earena/earena.html FastForWord** http://www.scilearn.com/pro ducts/ IMPACT** http://www.positscience.com /
LACE http://www.neurotone.com/l ace-interactive-listeningprogram
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Read my QUIPs
Harry Levitt
All
Listen to the wise or witty saying and enter what you think you heard. As your skills improve, the noise level gets louder.
$119.99
No
Sensimetrics (Arthur Boothroyd, 2003)
CI
Vowels, consonants, stress, intonation, length, and everyday communication
$85.00
Yes
Med-El
CI
Sentence level with options to adjust amount of noise, rate of speech, or gender of speaker. Telephone training activity also available. Scoring presented at end of session, but not stored.
Free
No
Communication Disorders Technology
HA
Syllable training using 100 of the most important sounds for speech perception; sentences from multiple talkers. Training in quiet or noise available
$150.00
Yes
Advanced Bionics
CI
Interactive listening at word and sentence level with discrimination and identification activities; telephone and music training options available.
Free
No
http://www.sensesynergy.co m/ Seeing and Hearing Speech http://www.seeingspeech.co m/ SoundScape http://www.medel.com/us/s oundscape/
SPATS http://www.comdistec.com/S PATS-ESL.html The Listening Room http://www.hearingjourney.c om/ListeningRoom
Asterisks denote programs developed based on CAST
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Table 2: Summaries of the nine studies reviewed. Reference
Program
Sample
Study Design
Results
Barcroft et al. (2011)
I Hear What You Mean
69 adult HA users
Two experimental groups, repeated measures
Both groups improved significantly on both single and multiple talker test versions
Training for 6 wks. with either single talker’s or six talkers’ speech
Multi-talker trainees improved more on multitalker test; single-talker trainees improved more on single-talker version
Single-talker and multitalker versions of outcome measure Fu & Galvin (2007)
Ingvalson et al. (2013)
Levitt et al. (2011)*
CAST
Seeing and Hearing Speech
Read My Quips
10 adult CI users with limited speech recognition.
5 post-lingually deafened adults
10 adult HA users (9 experienced, 1 new)
Single group, repeated measures
Vowel and consonant recognition significantly improved
Home training 1 hr/day, 5 days/wk, for > 1 mo.
Experimental group, with repeated measures.
Significant improvement in key word identification on HINT at favorable SNRs
4 AV speech-in-noise sessions: consonant and vowel recognition in words, phrases and sentences
Reduction in SNR loss on QuickSIN
Single group, repeated measures.
Mean improvement of 2.8 dB in SNR at which 50% of IEEE sentences were correctly identified
Home training30 min./day for 3 wks.
New HA user improved 15.5 dB.
Sentences presented in noise with visual (lipreading) cues. SNR changed adaptively.
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Miller et al. (2008b)*
SPATS
12 HA, 16 CI adults
Between subject repeated measures 12 training rotations at adapted SNRs on: 1) identification of syllable onsets and nuclei in quiet and in noise and 2) short sentences
Trained group: 11% mean gain Controls: No change Speech perception: measures: Trained group: Improved 17.6 points Control group: decreased 2 points SPATs questionnaire: Trained group: Improved 25% Control group: No change
Oba et al. (2011)
Sweetow & Henderson-Sabes (2004)
CAST: Sound Express
LACE
10 post-lingually deafened CI adults
8 experienced adult HA users
Single group, repeated measures
Digit recognition in babble (trained) and in steady state noise (not trained) improved
Home training, 30 min/day, 5 days/wk, for 4 wks.
Benefit generalized to improved HINT and IEEE in both types of noise
SNR adaptively changed based on performance
Training benefits retained 1 mo. post training
Between subject repeated measures.
Three of four trained participants improved on post-training and follow-up tests
Training 30 min/day, 5 days/wk, for 4 wks.
Control group: No change on any measures
Training with sentences at variable (-5 - +3 dB) SNRs Sweetow and Henderson-Sabes (2006)
LACE
65 subjects 56 HA users and 9 non-users with subjective complaints
Between group, repeated measures cross-over design Topic related sentences in noise
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Training group: Significant improvement Control group: No change Training effects maintained post-training
Zhang et al. (2012)
CAST: Sound Express
7 post-lingually deafened adults with bimodal (CI + HA) fittings
Single group, repeated measures
Speech-recognition improved for 6 of 7 subjects.
Home training 1hr/day, 5 days/wk, for 4 wks
Improvement retained 1 mo. after training
Identification of vowels, consonants, CNC words, sentences, voice gender, and emotion assessed in quiet and with multi-talker babble at 5dB SNR pre- and post-training
Asterisks denote studies that were not peer-reviewed.
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