Auditory training for adults with cochlear implants: a systematic review

Computer-based Auditory Training by New Adult Cochlear Implant Recipients Is Associated With Durable Improvements in Cochlear Implant Quality of Life

OBJECTIVE

The process of adapting to communicate with a cochlear implant (CI) is complex. The use of auditory training after cochlear implantation may help to facilitate improvements in postoperative speech recognition and quality-of-life outcomes in new adult CI recipients. However, the effectiveness of auditory training remains uncertain and long-term effects have not been examined in a large sample of new adult CI users. As such, the objective of this study was to examine the influence of common forms of auditory training on speech recognition and CI-related quality-of-life (CI-related QOL) outcomes at 1 year after cochlear implantation. We hypothesized that patients who reported use of computer-based auditory training (CBAT) would show improved speech and CIQOL-35 Profile scores at 1 year after activation of their implant, compared with their peers.

DESIGN

This study was designed as a prospective study and was undertaken at a tertiary academic CI center. Participants included 114 adults undergoing cochlear implantation for bilateral hearing loss. Patients serially self-reported use of the following types of post-CI auditory training over their first-year postactivation: (1) face-to-face training (e.g., speech-language pathologist), (2) passive home-based training (e.g., listening to audiobooks), and (3) CBAT (e.g., self-directed software). Outcomes measures for this study included change in Consonant-Nucleus-Consonant phoneme (CNCp), CNC word (CNCw), AzBio sentences in quiet, and CIQOL-35 Profile global and domain scores from pre-CI to 12-mo post-CI.

RESULTS

Of 114 patients, 94 (82.5%) used one or more auditory training resources. Of these, 19.3% used face-to-face training, 67.5% passive home-based training, and 46.5% CBAT. Of 114 patients, 73 had complete CIQOL data. At 12 mo, only CBAT use was associated with significantly greater improvements in global and all domain-specific CIQOL scores ( d -range  =  0.72-0.87), compared with those not using CBAT. Controlling for demographics and use of multiple training resources, CBAT remained the strongest positive predictor of CIQOL improvement, with significant associations with global score (ß  =  12.019[4.127,19.9]) and all domain scores at 12-mo post-CI: communication (ß  =  11.937[2.456,21.318), emotional (ß  =  12.293[1.827,22.759), entertainment (ß  =  17.014[5.434,28.774), environment (ß  =  13.771[1.814,25.727]), listening effort (ß  =  12.523[2.798,22.248]), and social (ß  =  18.114[7.403,28.826]). No significant benefits were noted with use of CBAT or any other form of auditory training and speech recognition scores at 12-mo post-CI ( d -range  =  -0.12-0.22).

CONCLUSIONS

Auditory training with CBAT was associated with improved CI-related QOL outcomes at 12-mo post-CI. Given its availability and low cost, this study provides evidence to support using CBAT to improve real-world functional abilities in new adult CI recipients.

Current practices and opinions on auditory training in adult cochlear implant recipients

OBJECTIVE

To examine current practices and opinions of cochlear implant (CI) providers with respect to post-implantation auditory training.

METHODS

A survey was submitted to the American Cochlear Implant Alliance membership that reviewed current practice and opinions with respect to post-implantation auditory training for adult CI recipients.

MAIN OUTCOME MEASURES

Review of respondent practice, center volume, role on CI team, and current usage and opinions surrounding auditory training, including resources used and schedule of use.

RESULTS

Most (79 %) of the 79 CI providers surveyed reported working at academic centers, 34 % at high-volume centers (>150 CIs/year), and 38 % were surgeons. Nearly all (99 %) respondents recommend auditory training for new adult CI recipients. Just over half (52 %) provide auditory training resources to the patient in the form of a broad list of patient-directed exercises from which a patient could select. A specific training resource, generally a computer-based auditory training program (e.g., AngelSound™), is recommended to patients by 30 % of the respondents. Regarding timing of rehabilitation, median preferred start time was 0 months (interquartile range [IQR] 0-1) post-activation. Sessions were preferably performed for a median of 3 h per week (IQR 2-4) and continued for a median of 12 months (IQR 6-12). Recommendations for auditory training were fairly consistent between surgeon and non-surgeon providers and by center volume. Non-surgeons more often had specific recommendations on training resources, benefits of music, and training condition (e.g., contralateral ear plugged).

CONCLUSIONS

Despite a lack of clinical guidelines for adult post-implantation auditory training, a cross-sectional survey of providers' current practices and opinions demonstrates that these services are widely recommended and regarded as valuable. Training is almost universally patient-directed and believed to be most beneficial if started soon after activation. Interestingly, specific recommendations for which training approaches to use are not common, suggesting a gap in provider knowledge of which resources are most efficacious.

Task-Specific Rapid Auditory Perceptual Learning in Adult Cochlear Implant Recipients: What Could It Mean for Speech Recognition

OBJECTIVES

Speech recognition in cochlear implant (CI) recipients is quite variable, particularly in challenging listening conditions. Demographic, audiological, and cognitive factors explain some, but not all, of this variance. The literature suggests that rapid auditory perceptual learning explains unique variance in speech recognition in listeners with normal hearing and those with hearing loss. The present study focuses on the early adaptation phase of task-specific rapid auditory perceptual learning. It investigates whether adult CI recipients exhibit this learning and, if so, whether it accounts for portions of the variance in their recognition of fast speech and speech in noise.

DESIGN

Thirty-six adult CI recipients (ages = 35 to 77, M = 55) completed a battery of general speech recognition tests (sentences in speech-shaped noise, four-talker babble noise, and natural-fast speech), cognitive measures (vocabulary, working memory, attention, and verbal processing speed), and a rapid auditory perceptual learning task with time-compressed speech. Accuracy in the general speech recognition tasks was modeled with a series of generalized mixed models that accounted for demographic, audiological, and cognitive factors before accounting for the contribution of task-specific rapid auditory perceptual learning of time-compressed speech.

RESULTS

Most CI recipients exhibited early task-specific rapid auditory perceptual learning of time-compressed speech within the course of the first 20 sentences. This early task-specific rapid auditory perceptual learning had unique contribution to the recognition of natural-fast speech in quiet and speech in noise, although the contribution to natural-fast speech may reflect the rapid learning that occurred in this task. When accounting for demographic and cognitive characteristics, an increase of 1 SD in the early task-specific rapid auditory perceptual learning rate was associated with ~52% increase in the odds of correctly recognizing natural-fast speech in quiet, and ~19% to 28% in the odds of correctly recognizing the different types of speech in noise. Age, vocabulary, attention, and verbal processing speed also had unique contributions to general speech recognition. However, their contribution varied between the different general speech recognition tests.

CONCLUSIONS

Consistent with previous findings in other populations, in CI recipients, early task-specific rapid auditory perceptual, learning also accounts for some of the individual differences in the recognition of speech in noise and natural-fast speech in quiet. Thus, across populations, the early rapid adaptation phase of task-specific rapid auditory perceptual learning might serve as a skill that supports speech recognition in various adverse conditions. In CI users, the ability to rapidly adapt to ongoing acoustical challenges may be one of the factors associated with good CI outcomes. Overall, CI recipients with higher cognitive resources and faster rapid learning rates had better speech recognition.

Investigating Perception to Production Transfer in Children With Cochlear Implants: A High Variability Phonetic Training Study

PURPOSE

This study builds upon an established effective training method to investigate the advantages of high variability phonetic identification training for enhancing lexical tone perception and production in Mandarin-speaking pediatric cochlear implant (CI) recipients, who typically face ongoing challenges in these areas.

METHOD

Thirty-two Mandarin-speaking children with CIs were quasirandomly assigned into the training group (TG) and the control group (CG). The 16 TG participants received five sessions of high variability phonetic training (HVPT) within a period of 3 weeks. The CG participants did not receive the training. Perception and production of Mandarin tones were administered before (pretest) and immediately after (posttest) the completion of HVPT via lexical tone recognition task and picture naming task. Both groups participated in the identical pretest and posttest with the same time frame between the two test sessions.

RESULTS

TG showed significant improvement from pretest to posttest in identifying Mandarin tones for both trained and untrained speech stimuli. Moreover, perceptual learning of HVPT significantly facilitated trainees' production of T1 and T2 as rated by a cohort of 10 Mandarin-speaking adults with normal hearing, which was corroborated by acoustic analyses revealing improved fundamental frequency (F0) median for T1 and T2 production and enlarged F0 movement for T2 production. In contrast, TG children's production of T3 and T4 showed nonsignificant changes across two test sessions. Meanwhile, CG did not exhibit significant changes in either perception or production.

CONCLUSIONS

The results suggest a limited and inconsistent transfer of perceptual learning to lexical tone production in children with CIs, which challenges the notion of a robust transfer and highlights the complexity of the interaction between perceptual training and production outcomes. Further research on individual differences with a longitudinal design is needed to optimize the training protocol or tailor interventions to better meet the diverse needs of learners.

Speech Sound Categories Affect Lexical Competition: Implications for Analytic Auditory Training

OBJECTIVES

We provide a novel application of psycholinguistic theories and methods to the field of auditory training to provide preliminary data regarding which minimal pair contrasts are more difficult for listeners with typical hearing to distinguish in real-time.

DESIGN

Using eye-tracking, participants heard a word and selected the corresponding image from a display of four: the target word, two unrelated words, and a word from one of four contrast categories (i.e., voiced-initial [e.g., peach-beach], voiced-final [e.g., back-bag], manner-initial [e.g., talk-sock], and manner-final [e.g., bat-bass]).

RESULTS

Fixations were monitored to measure how strongly words compete for recognition depending on the contrast type (voicing, manner) and location (word-initial or final). Manner contrasts competed more for recognition than did voicing contrasts, and contrasts that occurred in word-final position were harder to distinguish than word-initial position.

CONCLUSION

These results are an important initial step toward creating an evidence-based hierarchy for auditory training for individuals who use cochlear implants.

Systematic Review of Auditory Training Outcomes in Adult Cochlear Implant Recipients and Meta-Analysis of Outcomes

Objective: to review evidence on the efficacy of auditory training in adult cochlear implant recipients. Data Sources: PRISMA guidelines for a systematic review of the literature were followed. PubMed, Scopus, and CINAHL databases were queried on 29 June 2023 for terms involving cochlear implantation and auditory training. Studies were limited to the English language and adult patient populations. Study Selection: Three authors independently reviewed publications for inclusion in the review based on a priori inclusion and exclusion criteria. Inclusion criteria encompassed adult cochlear implant populations, an analysis of clinician- or patient-directed auditory training, and an analysis of one or more measures of speech recognition and/or patient-reported outcome. Exclusion criteria included studies with only pediatric implant populations, music or localization training in isolation, and single-sample case studies. Data Extraction: The data were collected regarding study design, patient population, auditory training modality, auditory training timing, speech outcomes, and data on the durability of outcomes. A quality assessment of the literature was performed using a quality metric adapted from the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) Working Group guidelines. Data Synthesis and Meta-Analysis: Data were qualitatively summarized for 23 studies. All but four studies demonstrated significant improvement in at least one measured or patient-reported outcome measure with training. For 11 studies with sufficient data reporting, pre-intervention and post-intervention pooled means of different outcome measures were compared for 132 patients using meta-analysis. Patient-direct training was associated with significant improvement in vowel-phoneme recognition and speech recognition in noise (p < 0.05 and p < 0.001, respectively), and clinician-directed training showed significant improvement in sentence recognition in noise (p < 0.001). Conclusions: The literature on auditory training for adult cochlear implant recipients is limited and heterogeneous, including a small number of studies with limited levels of evidence and external validity. However, the current evidence suggests that auditory training can improve speech recognition in adult cochlear implant recipients.

Phoneme Training for Adult Cochlear Implant Users: A Review of the Literature and Study Protocol

PURPOSE

This study describes a protocol for a novel individualized phoneme training program for adult cochlear implant (CI) users, based on individual phoneme confusion errors. The protocol is underpinned by a literature review on phoneme training and a focus group with adult CI users.

METHOD

After a literature search, five studies were included for review and evaluation of quality and level of evidence. A focus group with experienced adult CI users (n = 7) was then conducted to gain insights into their experiences of auditory training post-implantation and recommendations for future training programs. The knowledge gained from the literature review and focus group was used as the foundation for a novel, individualized phoneme training program for adult CI users, for which the protocol is described in this study.

RESULTS

A review of the literature shows that phoneme training in adult CI users has variable outcomes for on-task and off-task measures. Overall, the concept of individualized training relates to adaptive difficulty within training tasks and not to tailoring training content to participants' individual needs, as indicated by clinical outcomes. The focus group revealed that participants want to be able to track their training progress, have training content tailored to their individual needs, and expressed a preference for shorter training sessions.

CONCLUSIONS

Using learnings from a literature review and focus group, this study describes a protocol for a novel, individualized phoneme training program for adult CI users. Study findings from this phoneme training program will be disseminated when available.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.24392863.

Postoperative optimization of cochlear implantation for single sided deafness and asymmetric hearing loss: a systematic review

OBJECTIVE

Identify and evaluate the effectiveness of methods for improving postoperative cochlear implant (CI) hearing performance in subjects with single-sided deafness (SSD) and asymmetric hearing loss (AHL).

DATA SOURCES

Embase, PubMed, Scopus.

REVIEW METHODS

Systematic review and narrative synthesis. English language studies of adult CI recipients with SSD and AHL reporting a postoperative intervention and comparative audiometric data pertaining to speech in noise, speech in quiet and sound localization were included.

RESULTS

32 studies met criteria for full text review and 6 (n = 81) met final inclusion criteria. Interventions were categorized as: formal auditory training, programming techniques, or hardware optimization. Formal auditory training (n = 10) found no objective improvement in hearing outcomes. Experimental CI maps did not improve audiologic outcomes (n = 9). Programed CI signal delays to improve synchronization demonstrated improved sound localization (n = 12). Hardware optimization, including multidirectional (n = 29) and remote (n = 11) microphones, improved sound localization and speech in noise, respectively.

CONCLUSION

Few studies meeting inclusion criteria and small sample sizes highlight the need for further study. Formal auditory training did not appear to improve hearing outcomes. Programming techniques, such as CI signal delay, and hardware optimization, such as multidirectional and remote microphones, show promise to improve outcomes for SSD and AHL CI users.

Voice Parameters in Children With Cochlear Implants: A Systematic Review and Meta-Analysis

INTRODUCTION

An intact auditory system is essential for the development and maintenance of voice quality and speech prosody. On the contrary hearing loss affects the adjustments and appropriate use of organs involved in speech and voice production. Spectro-acoustic voice parameters have been evaluated in Cochlear Implant (CI) users, and the authors of previous systematic reviews on the topic concluded that fundamental frequency (F0) seemed preliminarily the most reliable parameter to evaluate voice alterations in adult CI users. The main aim of this systematic review and meta-analysis was to clarify the vocal parameters and prosodic alterations of speech in pediatric CI users.

MATERIALS AND METHODS

The protocol of the systematic review was registered on the PROSPERO database, International prospective register of systematic reviews. We conducted a search of the English literature published in the period between January 1, 2005 and April 1, 2022 on the Pubmed and Scopus databases. A meta-analysis was conducted to compare the values of voice acoustic parameters in CI users and non-hearing-impaired controls. The analysis was conducted using the standardized mean difference as the outcome measure. A random-effects model was fitted to the data.

RESULTS

A total of 1334 articles were initially evaluated using title and abstract screening. After applying inclusion/exclusion criteria, 20 articles were considered suitable for this review. The age of the cases ranged between 25 and 132 months at examination. The most studied parameters were F0, Jitter, Shimmer and Harmonics-to-Noise Ratio (HNR); other parameters were seldom reported. A total of 11 studies were included in the meta-analysis of F0, with the majority of estimates being positive (75%); the estimated average standardized mean difference based on the random-effects model was 0.3033 (95% CI: 0.0605 to 0.5462; P = 0.0144). For Jitter (0.2229; 95% CI: -0.1862 to 0.7986; P = 0.2229) and shimmer (0.2540; 95% CI: -0.1404 to 0.6485; P = 0.2068) there was a trend toward positive values without reaching statistical significance.

DISCUSSION AND CONCLUSIONS

This meta-analysis confirmed that higher F0 values have been observed in the pediatric population of CI users compared to age-matched normal hearing volunteers, whereas the parameters of voice noise were not significantly different between cases and controls. Prosodic aspects of language need further investigations. In longitudinal contexts, prolonged auditory experience with CI has brought voice parameters closer to the norm. Following the available evidence, we stress the utility of inclusion of vocal acoustic analysis in the clinical evaluation and follow-up of CI patients to optimize the rehabilitation process of pediatric patients with hearing loss.

Application of Patient Reported Outcome Measures in Cochlear Implant Patients: Implications for the Design of Specific Rehabilitation Programs

INTRODUCTION

Cochlear implants (CI) have been developed to enable satisfying verbal communication, while music perception has remained in the background in both the research and technological development, thus making CI users dissatisfied by the experience of listening to music. Indications for clinicians to test and train music abilities are at a preliminary stage compared to the existing and well-established hearing and speech rehabilitation programs. The main aim of the present study was to test the utility of the application of two different patient reporting outcome (PRO) measures in a group of CI users. A secondary objective was to identify items capable of driving the indication and design specific music rehabilitation programs for CI patients.

MATERIALS AND METHODS

A consecutive series of 73 CI patients referred to the Audiology Unit, University of Padova, was enrolled from November 2021 to May 2022 and evaluated with the audiological battery test and PRO measures: Musica e Qualità della Vita (MUSQUAV) and Nijmegen Cochlear Implant Questionnaire (NCIQ) Italian version.

RESULTS

The reliability analysis showed good consistency between the different PRO measures (Cronbach's alpha = 0.873). After accounting for the epidemiological and clinical variables, the PRO measures showed a correlation with audiological outcomes in only one case (rho = -0.304; adj. p = 0.039) for NCIQ-T with the CI-pure tone average. A willingness for musical rehabilitation was present in 63% of patients (Rehab Factor, mean value of 0.791 ± 0.675).

CONCLUSIONS

We support the role of the application of MUSQUAV and NCIQ to improve the clinical and audiological evaluation of CI patients. Moreover, we proposed a derivative item, called the rehab factor, which could be used in clinical practice and future studies to clarify the indication and priority of specific music rehabilitation programs.