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.

Predicting Early Cochlear Implant Performance: Can Cognitive Testing Help?

Introduction: There is significant variability in speech recognition outcomes in adults who receive cochlear implants (CIs). Little is known regarding cognitive influences on very early CI performance, during which significant neural plasticity occurs. Methods: Prospective study of 15 postlingually deafened adult CI candidates tested preoperatively with a battery of cognitive assessments. The mini-mental state exam (MMSE), forward digit span, Stroop measure of inhibition-concentration, and test of word reading efficiency were utilized to assess cognition. consonant-nucleus-consonant words, AZBio sentences in quiet, and AZBio sentences in noise (+10 dB SNR) were utilized to assess speech recognition at 1- and 3-months of CI use. Results: Performance in all speech measures at 1-month was moderately correlated with preoperative MMSE, but these correlations were not strongly correlated after correcting for multiple comparisons. There were large correlations of forward digit span with 1-month AzBio quiet (P ≤ 0.001, rho = 0.762) and AzBio noise (P ≤ 0.001, rho = 0.860), both of which were strong after correction. At 3 months, forward digit span was strongly predictive of AzBio noise (P ≤ 0.001, rho = 0.786), which was strongly correlated after correction. Changes in speech recognition scores were not correlated with preoperative cognitive test scores. Conclusions: Working memory capacity significantly predicted early CI sentence recognition performance in our small cohort, while other cognitive functions assessed did not. These results differ from prior studies predicting longer-term outcomes. Findings and further studies may lead to better preoperative counseling and help identify patients who require closer evaluation to ensure optimal CI performance.

Cochlear Implant Qualification in Noise Versus Quiet: Do Patients Demonstrate Similar Postoperative Benefits?

OBJECTIVE: To assess patient factors, audiometric performance, and patient-reported outcomes in cochlear implant (CI) patients who would not have qualified with in-quiet testing alone. STUDY DESIGN: Retrospective chart review. SETTING: Tertiary referral center. METHODS: Adult CI recipients implanted between 2012 and 2022 were identified. Patients with preoperative AzBio Quiet > 60% in the implanted ear, requiring multitalker babble to qualify, comprised the in-noise qualifying (NQ) group. NQ postoperative performance was compared with the in-quiet qualifying (QQ) group using CNC, AzBio Quiet, and AzBio +5 dB signal-to-noise ratio. Speech, Spatial and Qualities of Hearing Scale (SSQ), Cochlear Implant Quality of Life scale (CIQOL-10), and daily device usage were also compared between the groups. RESULTS: The QQ group (n = 771) and NQ group (n = 67) were similar in age and hearing loss duration. NQ had higher average preoperative and postoperative speech recognition scores. A larger proportion of QQ saw significant improvement in CNC and AzBio Quiet scores in the CI-only listening condition (eg, CI-only AzBio Quiet: 88% QQ vs 51% NQ, P < .001). Improvement in CI-only AzBio +5 dB and in all open set testing in the best-aided binaural listening condition was similar between groups (eg, Binaural AzBio Quiet 73% QQ vs 59% NQ, P = .345). Postoperative SSQ ratings, CIQOL scores, and device usage were also equivalent between both groups. CONCLUSION: Patients who require in-noise testing to meet CI candidacy demonstrate similar improvements in best-aided speech perception and patient-reported outcomes as in-QQ, supporting the use of in-noise testing to determine CI qualification for borderline CI candidates.

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.

Effect of Cochlear Implantation on Social Life.

OBJECTIVE: Explore the effects of hearing loss on social life and identify residual social life deficits that remain after cochlear implantation. STUDY DESIGN: Retrospective review of prospectively obtained data. SETTING: Tertiary care adult neurotology center. PATIENTS: Adults between the ages of 35 and 83 years were included with either normal hearing (NH) or a cochlear implant (CI). INTERVENTIONS: CI and non-CI-specific quality-of-life (QOL) surveys focused on social and overall QOL. MAIN OUTCOME MEASURES: (1) The difference in QOL survey responses between NH and CI participants. (2) The relationship between CI-specific global and social QOL responses and non-CI-specific social QOL responses in CI users. RESULTS: A total of 51 participants were included: 31 CI users and 20 NH participants. Of the social QOL questionnaires, CI users reported significantly poorer scores on Self-Efficacy in Social Interactions than NH peers ( p = 0.049). Both Self-Efficacy in Social Interactions scores and Social Isolation Questionnaire scores were significantly correlated with the CI-specific social domain of QOL ( r = 0.64 and -0.58, respectively). Only the Self-Efficacy in Social Interactions scores had a moderate association with global CI QOL ( r = 0.47). CONCLUSIONS: CI users self-report similar social life outcomes as their NH peers with the exception of poorer self-efficacy in social situations. Moreover, self-efficacy in social interactions and social isolation were associated with social QOL in CI users, and self-efficacy in social interactions was associated with broader CI-related QOL. Findings support the relevance of individuals' perception of social life to their overall QOL with a CI.

Feasibility of a Video Otoscope for Diagnosis of Otologic Pathology in the Pediatric Emergency Department.

OBJECTIVES: Performing pediatric otoscopy can be difficult secondary to patient compliance, which potentiates misdiagnosis and inaccurate treatment of acute otitis media. This study used a convenience sample to assess the feasibility of using a video otoscope for the examination of tympanic membranes in children presenting to a pediatric emergency department. METHODS: We obtained otoscopic videos using the JEDMED Horus + HD Video Otoscope. Participants were randomized to video or standard otoscopy, and a physician completed their bilateral ear examinations. In the video group, physicians reviewed otoscope videos with the patient's caregiver. The caregiver and physician completed separate surveys using a 5-point Likert Scale regarding perceptions of the otoscopic examination. A second physician reviewed each otoscopic video. RESULTS: We enrolled 213 participants in 2 groups (standard otoscopy, n = 94; video otoscopy, n = 119). We used Wilcoxon rank sum, Fisher exact test, and descriptive statistics to compare results across groups. For physicians, there were no statistically significant differences between groups with ease of device use, quality of otoscopic view, or diagnosis. There was moderate agreement between physician video otoscopic view satisfaction and slight agreement between physician video otologic diagnosis. Estimates of length of time to complete the ear examinations were longer more often for the video otoscope compared with standard for both caregivers (OR, 2.00; 95% confidence interval, 1.10-3.70; P = 0.02) and physicians (OR, 3.08; 95% confidence interval, 1.67-5.78; P < 0.01). There were no statistically significant differences between video and standard otoscopy with regard to caregiver perception of comfort, cooperation, satisfaction, or diagnosis understanding. CONCLUSIONS: Caregivers perceive that video otoscopy and standard otoscopy are comparable in comfort, cooperation, examination satisfaction, and diagnosis understanding. Physicians made a wider range of more subtle diagnoses with the video otoscope. However, examination length of time may limit the JEDMED Horus + HD Video Otoscope's feasibility in a busy pediatric emergency department.

Evaluating Listening Effort in Unilateral, Bimodal, and Bilateral Cochlear Implant Users.

OBJECTIVE: Evaluate listening effort (LE) in unilateral, bilateral, and bimodal cochlear implant (CI) users. Establish an easy-to-implement task of LE that could be useful for clinical decision making. STUDY DESIGN: Prospective cohort study. SETTING: Tertiary neurotology center. METHODS: The Sentence Final Word Identification and Recall Task, an established measure of LE, was modified to include challenging listening conditions (multitalker babble, gender, and emotional variation; test), in addition to single-talker sentences (control). Participants listened to lists of sentences in each condition and recalled the last word of each sentence. LE was quantified by percentage of words correctly recalled and was compared across conditions, across CI groups, and within subjects (best aided vs monaural). RESULTS: A total of 24 adults between the ages of 37 and 82 years enrolled, including 4 unilateral CI users (CI), 10 bilateral CI users (CICI), and 10 bimodal CI users (CIHA). Task condition impacted LE (P < .001), but hearing configuration and listener group did not (P = .90). Working memory capacity and contralateral hearing contributed to individual performance. CONCLUSION: This study adds to the growing body of literature on LE in challenging listening conditions for CI users and demonstrates feasibility of a simple behavioral task that could be implemented clinically to assess LE. This study also highlights the potential benefits of bimodal hearing and individual hearing and cognitive factors in understanding individual differences in performance, which will be evaluated through further research.

Audiovisual Processing Skills Before Cochlear Implantation Predict Postoperative Speech Recognition in Adults.

OBJECTIVES: Adults with hearing loss (HL) demonstrate greater benefits of adding visual cues to auditory cues (i.e., "visual enhancement" [VE]) during recognition of speech presented in a combined audiovisual (AV) fashion when compared with normal-hearing peers. For patients with moderate-to-profound sensorineural HL who receive cochlear implants (CIs), it is unclear whether the restoration of audibility results in a decrease in the VE provided by visual cues during AV speech recognition. Moreover, it is unclear whether increased VE during the experience of HL before CI is beneficial or maladaptive to ultimate speech recognition abilities after implantation. It is conceivable that greater VE before implantation contributes to the enormous variability in speech recognition outcomes demonstrated among patients with CIs. This study took a longitudinal approach to test two hypotheses: (H1) Adult listeners with HL who receive CIs would demonstrate a decrease in VE after implantation; and (H2) The magnitude of pre-CI VE would predict post-CI auditory-only speech recognition abilities 6 months after implantation, with the direction of that relation supporting a beneficial, redundant, or maladaptive effect on outcomes. DESIGN: Data were collected from 30 adults at two time points: immediately before CI surgery and 6 months after device activation. Pre-CI speech recognition performance was measured in auditory-only (A-only), visual-only, and combined AV fashion for City University of New York (CUNY) sentences. Scores of VE during AV sentence recognition were computed. At 6 months after CI activation, participants were again tested on CUNY sentence recognition in the same conditions as pre-CI. H1 was tested by comparing post- versus pre-CI VE scores. At 6 months of CI use, additional open-set speech recognition measures were also obtained in the A-only condition, including isolated words, words in meaningful AzBio sentences, and words in AzBio sentences in multitalker babble. To test H2, correlation analyses were performed to assess the relation between post-CI A-only speech recognition scores and pre-CI VE scores. RESULTS: Inconsistent with H1, after CI, participants did not demonstrate a significant decrease in VE scores. Consistent with H2, preoperative VE scores positively predicted postoperative scores of A-only sentence recognition for both sentences in quiet and in babble (rho = 0.40 to 0.45, p < 0.05), supporting a beneficial effect of pre-CI VE on post-CI auditory outcomes. Pre-CI VE was not significantly related to post-CI isolated word recognition. The raw pre-CI CUNY AV scores also predicted post-CI A-only speech recognition scores to a similar degree as VE scores. CONCLUSIONS: After implantation, CI users do not demonstrate a decrease in VE from before surgery. The degree of VE during AV speech recognition before CI positively predicts A-only sentence recognition outcomes after implantation, suggesting the potential value of AV testing of CI patients preoperatively to help predict and set expectations for postoperative outcomes.

Why Do Cochlear Implant Candidates Defer Surgery? A Retrospective Case-Control Study.

OBJECTIVE(S): Despite undergoing thorough cochlear implant (CI) candidacy evaluation and counseling, some patients ultimately elect against implantation. This study sought to identify patient-related and socioeconomic factors predicting CI deferral. METHODS: A retrospective study of adult (≥18 years old) CI candidates presenting between 2007 and 2021 at a tertiary academic CI center was performed. The primary outcome was device implantation. Data collected included age, gender, hearing status, race, zip code of residence, median family income (MFI), distance traveled from the CI center, marital status, employment status, and insurance status. Multivariable binary logistic regression was performed to identify predictors of implantation. RESULTS: A total of 200 patients qualifying for CI were included, encompassing 77 adults deferring surgery (CI-deferred) and 123 consecutive adults electing for surgery (CI-pursued). Age, gender, hearing status, insurance type, employment status, distance from the implant center, and MFI were comparable between the groups (p > 0.05). Compared to CI-pursued patients, CI-deferred patients were more likely to be non-Caucasian (24.7% vs. 9.8%, p = 0.015) and unmarried (55.8% vs. 38.2%, p = 0.015). On multivariable logistic regression, older age (OR 0.981, 0.964-0.998, p = 0.027), African American race (OR 0.227, 0.071-0.726, p = 0.012), and unmarried status (OR 0.505, 0.273-0.935, p = 0.030) were independent predictors of implant deferral. CONCLUSION: This study demonstrates that increasing age at evaluation, African American race, and unmarried status are predictors for deferring CI surgery despite being implant candidates. These patients may benefit from increased outreach in the form of counseling, education, and social support prior to undergoing CI surgery. LEVEL OF EVIDENCE: 3 - retrospective study with internal control group Laryngoscope, 134:2857-2863, 2024.

Development of a Sentence Verification Task to Measure Speech Comprehension and Listening Effort in Cochlear Implant Users.

PURPOSE: Tests measuring speech comprehension and listening effort for cochlear implant (CI) users may reflect important aspects of real-world speech communication. In this study, we describe the development of a multiple-talker, English-language sentence verification task (SVT) for use in adult CI users to measure speech comprehension and listening effort. We also examine whether talker differences affect speech comprehension and listening effort. METHOD: Thirteen experienced adult CI users participated in the study and underwent testing using a newly developed multiple-talker SVT. Participants were sequentially presented with audio recordings of unique sentences spoken in English by six different talkers. Participants classified each sentence as either true or false. Accuracy of classification and the response time (RT) for correct responses were used as measures of comprehension and listening effort, respectively. The effect of talker on the results was further analyzed. RESULTS: All 13 participants successfully completed the SVT. The mean verification accuracy for participants was 87.2% ± 8.8%. The mean RT for correct responses across participants was 1,050 ms ± 391 ms. When stratified by talker, verification accuracy ranged from 83.7% to 95.2% and mean RTs across participant ranged from 786 ms to 1,254 ms. Talker did not have a significant effect on sentence classification accuracy, but it did have a significant effect on RTs (p < .001). CONCLUSIONS: The SVT is an easily implemented test that can assess speech comprehension and listening effort simultaneously. CI users may experience increased effort for comprehending certain talkers' speech, despite showing similar levels of comprehension accuracy. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.24126630.

Emerging Relations among Cognitive Constructs and Cochlear Implant Outcomes: A Systematic Review and Meta-Analysis.

OBJECTIVE: Hearing loss has a detrimental impact on cognitive function. However, there is a lack of consensus on the impact of cochlear implants on cognition. This review systematically evaluates whether cochlear implants in adult patients lead to cognitive improvements and investigates the relations of cognition with speech recognition outcomes. DATA SOURCES: A literature review was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies evaluating cognition and cochlear implant outcomes in postlingual, adult patients from January 1996 to December 2021 were included. Of 2510 total references, 52 studies were included in qualitative analysis and 11 in meta-analyses. REVIEW METHODS: Proportions were extracted from studies of (1) the significant impacts of cochlear implantation on 6 cognitive domains and (2) associations between cognition and speech recognition outcomes. Meta-analyses were performed using random effects models on mean differences between pre- and postoperative performance on 4 cognitive assessments. RESULTS: Only half of the outcomes reported suggested cochlear implantation had a significant impact on cognition (50.8%), with the highest proportion in assessments of memory & learning and inhibition-concentration. Meta-analyses revealed significant improvements in global cognition and inhibition-concentration. Finally, 40.4% of associations between cognition and speech recognition outcomes were significant. CONCLUSION: Findings relating to cochlear implantation and cognition vary depending on the cognitive domain assessed and the study goal. Nonetheless, assessments of memory & learning, global cognition, and inhibition-concentration may represent tools to assess cognitive benefit after implantation and help explain variability in speech recognition outcomes. Enhanced selectivity in assessments of cognition is needed for clinical applicability.

Noise-Vocoded Sentence Recognition and the Use of Context in Older and Younger Adult Listeners.

PURPOSE: When listening to speech under adverse conditions, older adults, even with "age-normal" hearing, face challenges that may lead to poorer speech recognition than their younger peers. Older listeners generally demonstrate poorer suprathreshold auditory processing along with aging-related declines in neurocognitive functioning that may impair their ability to compensate using "top-down" cognitive-linguistic functions. This study explored top-down processing in older and younger adult listeners, specifically the use of semantic context during noise-vocoded sentence recognition. METHOD: Eighty-four adults with age-normal hearing (45 young normal-hearing [YNH] and 39 older normal-hearing [ONH] adults) participated. Participants were tested for recognition accuracy for two sets of noise-vocoded sentence materials: one that was semantically meaningful and the other that was syntactically appropriate but semantically anomalous. Participants were also tested for hearing ability and for neurocognitive functioning to assess working memory capacity, speed of lexical access, inhibitory control, and nonverbal fluid reasoning, as well as vocabulary knowledge. RESULTS: The ONH and YNH listeners made use of semantic context to a similar extent. Nonverbal reasoning predicted recognition of both meaningful and anomalous sentences, whereas pure-tone average contributed additionally to anomalous sentence recognition. None of the hearing, neurocognitive, or language measures significantly predicted the amount of context gain, computed as the difference score between meaningful and anomalous sentence recognition. However, exploratory cluster analyses demonstrated four listener profiles and suggested that individuals may vary in the strategies used to recognize speech under adverse listening conditions. CONCLUSIONS: Older and younger listeners made use of sentence context to similar degrees. Nonverbal reasoning was found to be a contributor to noise-vocoded sentence recognition. However, different listeners may approach the problem of recognizing meaningful speech under adverse conditions using different strategies based on their hearing, neurocognitive, and language profiles. These findings provide support for the complexity of bottom-up and top-down interactions during speech recognition under adverse listening conditions.

Advances in Artificial Intelligence to Diagnose Otitis Media: State of the Art Review.

OBJECTIVE: Otitis media (OM) is a model disease for developing, validating, and implementing artificial intelligence (AI) techniques. We aim to review the state of the art applications of AI used to diagnose OM in pediatric and adult populations. DATA SOURCES: Several comprehensive databases were searched to identify all articles that applied AI technologies to diagnose OM. REVIEW METHODS: Relevant articles from January 2010 through May 2021 were identified by title and abstract. Articles were excluded if they did not discuss AI in conjunction with diagnosing OM. References of included studies and relevant review articles were cross-referenced to identify any additional studies. CONCLUSION: Title and abstract screening resulted in full-text retrieval of 40 articles that met initial screening parameters. Of this total, secondary review articles (n = 7) and commentary-based articles (n = 2) were removed, as were articles that did not specifically discuss AI and OM diagnosis (n = 5), leaving 25 articles for review. Applications of AI technologies specific to diagnosing OM included machine learning and natural language processing (n = 23) and prototype approaches (n = 2). IMPLICATIONS FOR PRACTICE: This review emphasizes the utility of AI techniques to automate and aid in diagnosing OM. Although these techniques are still in the development and testing stages, AI has the potential to improve the practice of otolaryngologists and primary care clinicians by increasing the efficiency and accuracy of diagnoses.

Contribution of Verbal Learning & Memory and Spectro-Temporal Discrimination to Speech Recognition in Cochlear Implant Users.

OBJECTIVES: Existing cochlear implant (CI) outcomes research demonstrates a high degree of variability in device effectiveness among experienced CI users. Increasing evidence suggests that verbal learning and memory (VL&M) may have an influence on speech recognition with CIs. This study examined the relations in CI users between visual measures of VL&M and speech recognition in a series of models that also incorporated spectro-temporal discrimination. Predictions were that (1) speech recognition would be associated with VL&M abilities and (2) VL&M would contribute to speech recognition outcomes above and beyond spectro-temporal discrimination in multivariable models of speech recognition. METHODS: This cross-sectional study included 30 adult postlingually deaf experienced CI users who completed a nonauditory visual version of the California Verbal Learning Test-Second Edition (v-CVLT-II) to assess VL&M, and the Spectral-Temporally Modulated Ripple Test (SMRT), an auditory measure of spectro-temporal processing. Participants also completed a battery of word and sentence recognition tasks. RESULTS: CI users showed significant correlations between some v-CVLT-II measures (short-delay free- and cued-recall, retroactive interference, and "subjective" organizational recall strategies) and speech recognition measures. Performance on the SMRT was correlated with all speech recognition measures. Hierarchical multivariable linear regression analyses showed that SMRT performance accounted for a significant degree of speech recognition outcome variance. Moreover, for all speech recognition measures, VL&M scores contributed independently in addition to SMRT. CONCLUSION: Measures of spectro-temporal discrimination and VL&M were associated with speech recognition in CI users. After accounting for spectro-temporal discrimination, VL&M contributed independently to performance on measures of speech recognition for words and sentences produced by single and multiple talkers. LEVEL OF EVIDENCE: 3 Laryngoscope, 133:661-669, 2023.

Lack of neural contributions to the summating potential in humans with Meniere's disease.

Objective: To investigate the electrophysiology of the cochlear summating potential (SP) in patients with Meniere's disease (MD). Although long considered a purely hair cell potential, recent studies show a neural contribution to the SP. Patients with MD have an enhanced SP compared to those without the disease. Consequently, this study was to determine if the enhancement of the SP was in whole or part due to neural dysfunction. Design: Study participants included 41 adults with MD and 53 subjects with auditory neuropathy spectrum disorder (ANSD), undergoing surgery where the round window was accessible. ANSD is a condition with known neural dysfunction, and thus represents a control group for the study. The ANSD subjects and 17 of the MD subjects were undergoing cochlear implantation (CI) surgery; the remaining MD subjects were undergoing either endolymphatic sac decompression or labyrinthectomy to alleviate the symptoms of MD. Electrocochleography was recorded from the round window using high intensity (90 dB nHL) tone bursts. The SP and compound action potential (CAP) were measured to high frequencies (> = 2 kHz) and the SP, cochlear microphonic (CM) and auditory nerve neurophonic (ANN) to low frequencies. Linear mixed models were used to assess differences between MD and ANSD subjects. Results: Across frequencies, the MD subjects had smaller alternating current (AC) response than the ANSD subjects (F = 31.61,534, p < 0.001), but the SP magnitudes were larger (F = 94.31,534, p < 0.001). For frequencies less than 4 kHz the SP magnitude in the MD group was significantly correlated with the magnitude of the CM (p's < 0.001) but not in the ANSD group (p's > 0.05). Finally, the relative proportions of both ANN and CAP were greater in MD compared to ANSD subjects. The shapes of the waveforms in the MD subjects showed the presence of multiple components contributing to the SP, including outer and inner hair cells and neural activity. Conclusion: The results support the view that the increased negative polarity SP in MD subjects is due to a change in the operating point of hair cells rather than a loss of neural contribution. The steady-state SP to tones in human subjects is a mixture of different sources with different polarities.

Preoperative Reading Efficiency as a Predictor of Adult Cochlear Implant Outcomes.

HYPOTHESES: 1) Scores of reading efficiency (the Test of Word Reading Efficiency, second edition) obtained in adults before cochlear implant surgery will be predictive of speech recognition outcomes 6 months after surgery; and 2) Cochlear implantation will lead to improvements in language processing as measured through reading efficiency from preimplantation to postimplantation. BACKGROUND: Adult cochlear implant (CI) users display remarkable variability in speech recognition outcomes. "Top-down" processing-the use of cognitive resources to make sense of degraded speech-contributes to speech recognition abilities in CI users. One area that has received little attention is the efficiency of lexical and phonological processing. In this study, a visual measure of word and nonword reading efficiency-relying on lexical and phonological processing, respectively-was investigated for its ability to predict CI speech recognition outcomes, as well as to identify any improvements after implantation. METHODS: Twenty-four postlingually deaf adult CI candidates were tested on the Test of Word Reading Efficiency, Second Edition preoperatively and again 6 months post-CI. Six-month post-CI speech recognition measures were also assessed across a battery of word and sentence recognition. RESULTS: Preoperative nonword reading scores were moderately predictive of sentence recognition outcomes, but real word reading scores were not; word recognition scores were not predicted by either. No 6-month post-CI improvement was demonstrated in either word or nonword reading efficiency. CONCLUSION: Phonological processing as measured by the Test of Word Reading Efficiency, Second Edition nonword reading predicts to a moderate degree 6-month sentence recognition outcomes in adult CI users. Reading efficiency did not improve after implantation, although this could be because of the relatively short duration of CI use.

Factors affecting talker discrimination ability in adult cochlear implant users.

INTRODUCTION: Real-world speech communication involves interacting with many talkers with diverse voices and accents. Many adults with cochlear implants (CIs) demonstrate poor talker discrimination, which may contribute to real-world communication difficulties. However, the factors contributing to talker discrimination ability, and how discrimination ability relates to speech recognition outcomes in adult CI users are still unknown. The current study investigated talker discrimination ability in adult CI users, and the contributions of age, auditory sensitivity, and neurocognitive skills. In addition, the relation between talker discrimination ability and multiple-talker sentence recognition was explored. METHODS: Fourteen post-lingually deaf adult CI users (3 female, 11 male) with ≥1 year of CI use completed a talker discrimination task. Participants listened to two monosyllabic English words, produced by the same talker or by two different talkers, and indicated if the words were produced by the same or different talkers. Nine female and nine male native English talkers were paired, resulting in same- and different-talker pairs as well as same-gender and mixed-gender pairs. Participants also completed measures of spectro-temporal processing, neurocognitive skills, and multiple-talker sentence recognition. RESULTS: CI users showed poor same-gender talker discrimination, but relatively good mixed-gender talker discrimination. Older age and weaker neurocognitive skills, in particular inhibitory control, were associated with less accurate mixed-gender talker discrimination. Same-gender discrimination was significantly related to multiple-talker sentence recognition accuracy. CONCLUSION: Adult CI users demonstrate overall poor talker discrimination ability. Individual differences in mixed-gender discrimination ability were related to age and neurocognitive skills, suggesting that these factors contribute to the ability to make use of available, degraded talker characteristics. Same-gender talker discrimination was associated with multiple-talker sentence recognition, suggesting that access to subtle talker-specific cues may be important for speech recognition in challenging listening conditions.

Lexical Effects on the Perceived Clarity of Noise-Vocoded Speech in Younger and Older Listeners.

When listening to degraded speech, such as speech delivered by a cochlear implant (CI), listeners make use of top-down linguistic knowledge to facilitate speech recognition. Lexical knowledge supports speech recognition and enhances the perceived clarity of speech. Yet, the extent to which lexical knowledge can be used to effectively compensate for degraded input may depend on the degree of degradation and the listener's age. The current study investigated lexical effects in the compensation for speech that was degraded via noise-vocoding in younger and older listeners. In an online experiment, younger and older normal-hearing (NH) listeners rated the clarity of noise-vocoded sentences on a scale from 1 ("very unclear") to 7 ("completely clear"). Lexical information was provided by matching text primes and the lexical content of the target utterance. Half of the sentences were preceded by a matching text prime, while half were preceded by a non-matching prime. Each sentence also consisted of three key words of high or low lexical frequency and neighborhood density. Sentences were processed to simulate CI hearing, using an eight-channel noise vocoder with varying filter slopes. Results showed that lexical information impacted the perceived clarity of noise-vocoded speech. Noise-vocoded speech was perceived as clearer when preceded by a matching prime, and when sentences included key words with high lexical frequency and low neighborhood density. However, the strength of the lexical effects depended on the level of degradation. Matching text primes had a greater impact for speech with poorer spectral resolution, but lexical content had a smaller impact for speech with poorer spectral resolution. Finally, lexical information appeared to benefit both younger and older listeners. Findings demonstrate that lexical knowledge can be employed by younger and older listeners in cognitive compensation during the processing of noise-vocoded speech. However, lexical content may not be as reliable when the signal is highly degraded. Clinical implications are that for adult CI users, lexical knowledge might be used to compensate for the degraded speech signal, regardless of age, but some CI users may be hindered by a relatively poor signal.

Preoperative Visual Measures of Verbal Learning and Memory and their Relations to Speech Recognition After Cochlear Implantation.

OBJECTIVES: This study examined the performance of a group of adult cochlear implant (CI) candidates (CIC) on visual tasks of verbal learning and memory. Preoperative verbal learning and memory abilities of the CIC group were compared with a group of older normal-hearing (ONH) control participants. Relations between preoperative verbal learning and memory measures and speech recognition outcomes after 6 mo of CI use were also investigated for a subgroup of the CICs. DESIGN: A group of 80 older adult participants completed a visually presented multitrial free recall task. Measures of word recall, repetition learning, and the use of self-generated organizational strategies were collected from a group of 49 CICs, before cochlear implantation, and a group of 31 ONH controls. Speech recognition outcomes were also collected from a subgroup of 32 of the CIC participants who returned for testing 6 mo after CI activation. RESULTS: CICs demonstrated poorer verbal learning performance compared with the group of ONH control participants. Among the preoperative verbal learning and memory measures, repetition learning slope and measures of self-generated organizational clustering strategies were the strongest predictors of post-CI speech recognition outcomes. CONCLUSIONS: Older adult CI candidates present with verbal learning and memory deficits compared with older adults without hearing loss, even on visual tasks that are independent from the direct effects of audibility. Preoperative verbal learning and memory processes reflecting repetition learning and self-generated organizational strategies in free recall were associated with speech recognition outcomes 6 months after implantation. The pattern of results suggests that visual measures of verbal learning may be a useful predictor of outcomes in postlingual adult CICs.