Effects of Age and Noise Exposure History on Auditory Nerve Response Amplitudes: A Systematic Review, Study, and Meta-Analysis.

Auditory nerve (AN) function has been hypothesized to deteriorate with age and noise exposure. Here, we perform a systematic review of published studies and find that the evidence for age-related deficits in AN function is largely consistent across the literature, but there are inconsistent findings among studies of noise exposure history. Further, evidence from animal studies suggests that the greatest deficits in AN response amplitudes are found in noise-exposed aged mice, but a test of the interaction between effects of age and noise exposure on AN function has not been conducted in humans. We report a study of our own examining differences in the response amplitude of the compound action potential N1 (CAP N1) between younger and older adults with and without a self-reported history of noise exposure in a large sample of human participants (63 younger adults 18-30 years of age, 103 older adults 50-86 years of age). CAP N1 response amplitudes were smaller in older than younger adults. Noise exposure history did not appear to predict CAP N1 response amplitudes, nor did the effect of noise exposure history interact with age. We then incorporated our results into two meta-analyses of published studies of age and noise exposure history effects on AN response amplitudes in neurotypical human samples. The meta-analyses found that age effects across studies are robust (r=-0.407), but noise-exposure effects are weak (r=-0.152). We conclude that noise-exposure effects may be highly variable depending on sample characteristics, study design, and statistical approach, and researchers should be cautious when interpreting results. The underlying pathology of age-related and noise-induced changes in AN function are difficult to determine in living humans, creating a need for longitudinal studies of changes in AN function across the lifespan and histological examination of the AN from temporal bones collected post-mortem.

Talker change detection by listeners varying in age and hearing loss.

Despite a vast literature on how speech intelligibility is affected by hearing loss and advanced age, remarkably little is known about the perception of talker-related information in these populations. Here, we assessed the ability of listeners to detect whether a change in talker occurred while listening to and identifying sentence-length sequences of words. Participants were recruited in four groups that differed in their age (younger/older) and hearing status (normal/impaired). The task was conducted in quiet or in a background of same-sex two-talker speech babble. We found that age and hearing loss had detrimental effects on talker change detection, in addition to their expected effects on word recognition. We also found subtle differences in the effects of age and hearing loss for trials in which the talker changed vs trials in which the talker did not change. These findings suggest that part of the difficulty encountered by older listeners, and by listeners with hearing loss, when communicating in group situations, may be due to a reduced ability to identify and discriminate between the participants in the conversation.

Soft classification and regression analysis of audiometric phenotypes of age-related hearing loss.

Age-related hearing loss has a complex etiology. Researchers have made efforts to classify relevant audiometric phenotypes, aiming to enhance medical interventions and improve hearing health. We leveraged existing pattern analyses of age-related hearing loss and implemented the phenotype classification via quadratic discriminant analysis (QDA). We herein propose a method for analyzing the exposure effects on the soft classification probabilities of the phenotypes via estimating equations. Under reasonable assumptions, the estimating equations are unbiased and lead to consistent estimators. The resulting estimator had good finite sample performances in simulation studies. As an illustrative example, we applied our proposed methods to assess the association between a dietary intake pattern, assessed as adherence scores for the dietary approaches to stop hypertension diet calculated using validated food-frequency questionnaires, and audiometric phenotypes (older-normal, metabolic, sensory, and metabolic plus sensory), determined based on data obtained in the Nurses' Health Study II Conservation of Hearing Study, the Audiology Assessment Arm. Our findings suggested that participants with a more healthful dietary pattern were less likely to develop the metabolic plus sensory phenotype of age-related hearing loss.

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.

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.

A Pragmatic Clinical Trial of Hearing Screening in Primary Care Clinics: Effect of Setting and Provider Encouragement.

OBJECTIVES: The prevalence of hearing loss increases with age. Untreated hearing loss is associated with poorer communication abilities and negative health consequences, such as increased risk of dementia, increased odds of falling, and depression. Nonetheless, evidence is insufficient to support the benefits of universal hearing screening in asymptomatic older adults. The primary goal of the present study was to compare three hearing screening protocols that differed in their level of support by the primary care (PC) clinic and provider. The protocols varied in setting (in-clinic versus at-home screening) and in primary care provider (PCP) encouragement for hearing screening (yes versus no). DESIGN: We conducted a multisite, pragmatic clinical trial. A total of 660 adults aged 65 to 75 years; 64.1% female; 35.3% African American/Black completed the trial. Three hearing screening protocols were studied, with 220 patients enrolled in each protocol. All protocols included written educational materials about hearing loss and instructions on how to complete the self-administered telephone-based hearing screening but varied in the level of support provided in the clinic setting and by the provider. The protocols were as follows: (1) no provider encouragement to complete the hearing screening at home, (2) provider encouragement to complete the hearing screening at home, and (3) provider encouragement and clinical support to complete the hearing screening after the provider visit while in the clinic. Our primary outcome was the percentage of patients who completed the hearing screening within 60 days of a routine PC visit. Secondary outcomes following patient access of hearing healthcare were also considered and consisted of the percentage of patients who completed and failed the screening and who (1) scheduled, and (2) completed a diagnostic evaluation. For patients who completed the diagnostic evaluation, we also examined the percentage of those who received a hearing loss intervention plan by a hearing healthcare provider. RESULTS: All patients who had provider encouragement and support to complete the screening in the clinic completed the screening (100%) versus 26.8% with encouragement to complete the screening at home. For patients who were offered hearing screening at home, completion rates were similar regardless of provider encouragement (26.8% with encouragement versus 22.7% without encouragement); adjusted odds ratio of 1.25 (95% confidence interval 0.80-1.94). Regarding the secondary outcomes, roughly half (38.9-57.1% depending on group) of all patients who failed the hearing screening scheduled and completed a formal diagnostic evaluation. The percentage of patients who completed a diagnostic evaluation and received a hearing loss intervention plan was 35.0% to 50.0% depending on the group. Rates of a hearing loss intervention plan by audiologists ranged from 28.6% to 47.5% and were higher compared with those by otolaryngology providers, which ranged from 15.0% to 20.8% among the groups. CONCLUSIONS: The results of the pragmatic clinical trial showed that offering provider encouragement and screening facilities in the PC clinic led to a significantly higher rate of adherence with hearing screening associated with a single encounter. However, provider encouragement did not improve the significantly lower rate of adherence with home-based hearing screening.

The Revised Hearing Handicap Inventory and Pure-Tone Average Predict Hearing Aid Use Equally Well.

PURPOSE: This study aimed to (a) compare the Revised Hearing Handicap Inventory (RHHI) and pure-tone average (PTA) in their abilities to predict hearing aid use and (b) report the optimal cut-point values on the RHHI and PTA that predict hearing aid use. METHOD: Participants were from a community-based cohort study. We evaluated the ability of the RHHI and PTA as (a) continuous variables and (b) binary variables characterized by the optimal cut point determined by the Youden Index to predict hearing aid use. RHHI scores range from 0 to 72, and PTA was defined as averaged thresholds at frequencies 0.5, 1.0, 2.0, and 4.0 kHz in the worse ear. We used logistic regression models and receiver operating characteristic curves with corresponding concordance statistics (c-statistics) and 95% confidence intervals (CIs) to determine the predictive ability of models and chi-square tests to determine whether c-statistics were significantly different. RESULTS: This study included 581 participants (Mage = 72.9 [SD = 9.9] years; 59.9% female; 14.3% Minority race). The c-statistics for the RHHI (0.79, 95% CI [0.75, 0.83]) and PTA (0.81, 95% CI [0.78, 0.85]), as continuous variables, were not significantly different (p = .25). The optimal cut points for the RHHI and PTA to predict hearing aid use were 6 points and 32.5 dB HL, respectively. The c-statistics for the RHHI (0.72, 95% CI [0.68, 0.76]) and PTA (0.75, 95% CI [0.71, 0.79]), as binary variables, were not significantly different (p = .27). CONCLUSION: The RHHI and PTA are similar in their ability to predict hearing aid use.

Metabolic and Sensory Components of Age-Related Hearing Loss: Associations With Distortion- and Reflection-Based Otoacoustic Emissions.

Age-related hearing loss is difficult to study in humans because multiple genetic and environmental risk factors may contribute to pathology and cochlear function declines in older adults. These pathologies, including degeneration of the stria vascularis, are hypothesized to affect outer hair cells responsible for active cochlear amplification of low-level sounds. Otoacoustic emission (OAE) measures are used to quantify the energy added to the traveling wave in cochlear amplification, which typically weakens with increased pure-tone thresholds and for older individuals. Thus, the current study evaluated two OAE measures for individuals with different components of age-related hearing loss. We examined two retrospective adult lifespan datasets (18 to 89+ years of age) from independent sites (Medical University of South Carolina and Boys Town National Research Hospital), which included demographics, noise history questionnaires, distortion-product otoacoustic emissions (DPOAE), and cochlear reflectance (CR). Metabolic and sensory estimates of age-related hearing loss were derived from the audiograms in each dataset, and then tested for associations with DPOAE and CR. The results showed that metabolic estimates increased for older participants and were associated with lower overall DPOAE and CR magnitudes across frequency (i.e., lower fitted intercepts). Sensory estimates were significantly higher for males, who reported more positive noise histories compared to females and were associated with steeper negative across-frequency slopes for DPOAEs. Although significant associations were observed between OAE configurations, DPOAEs appeared uniquely sensitive to metabolic estimates. The current findings suggest that distortion-based measures may provide greater sensitivity than reflection-based measures to the components of age-related hearing loss.

Sentence recognition with modulation-filtered speech segments for younger and older adults: Effects of hearing impairment and cognition.

This study investigated word recognition for sentences temporally filtered within and across acoustic-phonetic segments providing primarily vocalic or consonantal cues. Amplitude modulation was filtered at syllabic (0-8 Hz) or slow phonemic (8-16 Hz) rates. Sentence-level modulation properties were also varied by amplifying or attenuating segments. Participants were older adults with normal or impaired hearing. Older adult speech recognition was compared to groups of younger normal-hearing adults who heard speech unmodified or spectrally shaped with and without threshold matching noise that matched audibility to hearing-impaired thresholds. Participants also completed cognitive and speech recognition measures. Overall, results confirm the primary contribution of syllabic speech modulations to recognition and demonstrate the importance of these modulations across vowel and consonant segments. Group differences demonstrated a hearing loss-related impairment in processing modulation-filtered speech, particularly at 8-16 Hz. This impairment could not be fully explained by age or poorer audibility. Principal components analysis identified a single factor score that summarized speech recognition across modulation-filtered conditions; analysis of individual differences explained 81% of the variance in this summary factor among the older adults with hearing loss. These results suggest that a combination of cognitive abilities and speech glimpsing abilities contribute to speech recognition in this group.

Accurate phenotypic classification and exome sequencing allow identification of novel genes and variants associated with adult-onset hearing loss.

Adult-onset progressive hearing loss is a common, complex disease with a strong genetic component. Although to date over 150 genes have been identified as contributing to human hearing loss, many more remain to be discovered, as does most of the underlying genetic diversity. Many different variants have been found to underlie adult-onset hearing loss, but they tend to be rare variants with a high impact upon the gene product. It is likely that combinations of more common, lower impact variants also play a role in the prevalence of the disease. Here we present our exome study of hearing loss in a cohort of 532 older adult volunteers with extensive phenotypic data, including 99 older adults with normal hearing, an important control set. Firstly, we carried out an outlier analysis to identify genes with a high variant load in older adults with hearing loss compared to those with normal hearing. Secondly, we used audiometric threshold data to identify individual variants which appear to contribute to different threshold values. We followed up these analyses in a second cohort. Using these approaches, we identified genes and variants linked to better hearing as well as those linked to worse hearing. These analyses identified some known deafness genes, demonstrating proof of principle of our approach. However, most of the candidate genes are novel associations with hearing loss. While the results support the suggestion that genes responsible for severe deafness may also be involved in milder hearing loss, they also suggest that there are many more genes involved in hearing which remain to be identified. Our candidate gene lists may provide useful starting points for improved diagnosis and drug development.

Gray matter and episodic memory associations with olfaction in middle-aged to older adults.

BACKGROUND: Age-related declines in olfaction contribute to low quality of life and appear to occur with declines in cognitive function, including diminished episodic memory. We tested the hypothesis that low gray matter volume within cortical regions that support olfaction and episodic memory can explain age-related differences in olfactory and episodic memory functions. METHODS: T1-weighted images, Sniffin' Sticks olfactory measures, and the NIH Toolbox-Cognition Battery were administered to 131 middle-aged to older adults (50-86 years; 66% female). Correlation was used to examine the associations between these measures. A network-based image processing approach was then used to examine the degree to which spatial patterns of gray matter variance were related to the olfactory and cognitive measures. Structural equation modeling was used to characterize the relative specificity of olfactory, cognitive, gray matter, and aging associations. RESULTS: Olfactory threshold, discrimination, and identification exhibited small to medium effect size associations with episodic memory performance (rs = 0.27-0.42, ps < 0.002). Gray matter volume within medial temporal and orbitofrontal cortex was also related to olfactory (discrimination and identification) and episodic memory function (rs = 0.21-0.36, ps < 0.019). Age and episodic memory explained the same variance in olfaction that was explained by the medial temporal and orbitofrontal pattern of gray matter volume. CONCLUSIONS: The results of this cross-sectional study suggest that identifying mechanisms contributing to differences in medial temporal and orbitofrontal cortex will advance our understanding of co-morbid olfactory and cognitive declines.

Determinants of Cochlear Implant Satisfaction and Decisional Regret in Adult Cochlear Implant Users.

OBJECTIVE: Determine associations expected and actual cochlear implant (CI) outcomes, decisional regret, and satisfaction in experienced adult CI users. STUDY DESIGN: Cross-sectional cohort study. SETTING: Tertiary medical center. PATIENTS: Thirty-nine adult CI users meeting traditional bilateral hearing loss indications with ≥12 months CI experience. INTERVENTIONS/MAIN OUTCOME MEASURES: Patients completed the validated Satisfaction with Amplification in Daily Living and Decisional Regret instruments. Pre- and post-CI outcomes (CI Quality of Life [CIQOL]-Expectations; CIQOL-35 Profile; CNC words, AzBio Sentences) were obtained from a prospectively maintained clinical database. RESULTS: Using established cutoff scores, 29% of patients reported a substantial degree of post-CI decisional regret. For each CIQOL domain, patients without decisional regret obtained post-CI outcome scores closer to pre-CI expectations compared with patients with decisional regret ( d = 0.34 to 0.91); similar results were observed with higher CI user satisfaction ( d = 0.17-0.83). Notably, the degree of pre- to post-CI improvement in CNC or AzBio scores did not differ between patients with and without decisional regret or with lower and higher satisfaction. Finally, greater pre-/postimprovement in CIQOL-35 Profile domain scores demonstrated far stronger associations with lower decisional regret and higher satisfaction than changes in speech recognition scores. CONCLUSIONS: Patients with better alignment of their pre-CI expectations and post-CI outcomes and greater pre-/post-CIQOL improvement had lower decisional regret and higher satisfaction. This emphasizes the importance of evidence-based pre-CI counseling regarding real-world CI benefits and caution against assuming that improvements in speech recognition are related to patient satisfaction.

Discrepancies Between Expected and Actual Cochlear Implant-Related Functional Outcomes.

OBJECTIVE: Previous research has demonstrated that realistic patient expectations are a critical factor in determining cochlear implant (CI) candidacy. The current study uses the validated Cochlear Implant Quality of Life-Expectations (CIQOL-Expectations) instrument to determine expectations of potential CI users and the degree to which their pre-CI expectations are met after implantation. STUDY DESIGN: Prospective cohort study. SETTING: Tertiary medical center. PATIENTS: Sixty adult CI patients. INTERVENTIONS/MAIN OUTCOME MEASURES: Pre-CI aided and post-CI consonant-nucleus-consonant word and AzBio sentence scores, pre-CI CIQOL-Expectations, and pre-CI and 3/6/12-month post-CI CIQOL-35 Profile scores. RESULTS: Mean pre-CI CIQOL-Expectations exceeded 12-month mean CIQOL-35 Profile scores for the global measure and the communication, environment, and listening effort domains ( d = 0.65-0.97). The communication and listening effort domain scores had the largest discrepancy between expected and actual post-CI improvement (actual scores, 15.1 and 16.3 points lower than expected [ d = 0.93-0.97], respectively). For 42% of patients, pre-CI global expectations exceeded 12-month post-CI CIQOL-35 Profile global scores, 49% met their expectations, and actual scores exceeded expectations for only 10% of patients. Similar patterns were seen for all CIQOL domains except emotional. CONCLUSIONS: Post-CI functional abilities seem to fall short of pre-CI expectations for a substantial percentage of CI users, which was most apparent for the communication and listening effort CIQOL domains. These results may help clinicians direct personalized counseling toward common misconceptions, which can aid shared decision making and potentially minimize the mismatch between expected and realized outcomes.Level of Evidence: III.IRB Pro00073019, approved December 20, 2017 (Medical University of South Carolina).

The Stria Vascularis in Mice and Humans Is an Early Site of Age-Related Cochlear Degeneration, Macrophage Dysfunction, and Inflammation.

Age-related hearing loss, or presbyacusis, is a common degenerative disorder affecting communication and quality of life for millions of older adults. Multiple pathophysiologic manifestations, along with many cellular and molecular alterations, have been linked to presbyacusis; however, the initial events and causal factors have not been clearly established. Comparisons of the transcriptome in the lateral wall (LW) with other cochlear regions in a mouse model (of both sexes) of "normal" age-related hearing loss revealed that early pathophysiological alterations in the stria vascularis (SV) are associated with increased macrophage activation and a molecular signature indicative of inflammaging, a common form of immune dysfunction. Structure-function correlation analyses in mice across the lifespan showed that the age-dependent increase in macrophage activation in the stria vascularis is associated with a decline in auditory sensitivity. High-resolution imaging analysis of macrophage activation in middle-aged and aged mouse and human cochleas, along with transcriptomic analysis of age-dependent changes in mouse cochlear macrophage gene expression, support the hypothesis that aberrant macrophage activity is an important contributor to age-dependent strial dysfunction, cochlear pathology, and hearing loss. Thus, this study highlights the SV as a primary site of age-related cochlear degeneration and aberrant macrophage activity and dysregulation of the immune system as early indicators of age-related cochlear pathology and hearing loss. Importantly, novel new imaging methods described here now provide a means to analyze human temporal bones in a way that had not previously been feasible and thereby represent a significant new tool for otopathological evaluation.SIGNIFICANCE STATEMENT Age-related hearing loss is a common neurodegenerative disorder affecting communication and quality of life. Current interventions (primarily hearing aids and cochlear implants) offer imperfect and often unsuccessful therapeutic outcomes. Identification of early pathology and causal factors is crucial for the development of new treatments and early diagnostic tests. Here, we find that the SV, a nonsensory component of the cochlea, is an early site of structural and functional pathology in mice and humans that is characterized by aberrant immune cell activity. We also establish a new technique for evaluating cochleas from human temporal bones, an important but understudied area of research because of a lack of well-preserved human specimens and difficult tissue preparation and processing approaches.

Conditional Minimal Detectable Change for the Cochlear Implant Quality of Life-35 Profile Associated With Improved Functional Abilities 12 Months After Cochlear Implantation.

Importance: It is essential to measure an individual patient's baseline and follow-up abilities to demonstrate changes in clinical outcomes over time. Inherent in this strategy is interpreting whether the measured change is clinically significant and beyond measurement error. Conditional minimal detectable change (cMDC) values are widely used in many disciplines but have rarely been established for outcome measures in otolaryngology or hearing research, and never in cochlear implantation. Objective: To determine cMDC values for the Cochlear Implant Quality of Life-35 (CIQOL-35) Profile instrument to enhance our understanding of the initial and ongoing changes in functional abilities from cochlear implants (CIs). Design, Setting, and Participants: Item response theory analyses of responses from a multi-institutional cohort of 705 CI users at a tertiary CI center were used to derive standard error (SE) values for each possible CIQOL-35 domain score. Using an iterative approach, these SE values were used to calculate cMDC values for every possible pre-CI and post-CI domain score combination. We then compared pre-CI to 12-month post-CI CIQOL-35 domains scores in an independent cohort of 65 adult CI users to determine whether the measured change exceeded error to be clinically significant. The analysis took place on December 14, 2022. Interventions: The CIQOL-35 Profile instrument and cochlear implantation. Results: The cMDC values were smaller for the communication domain, and global measure and cMDC values for all domains were larger at the extremes of the measurement scale. Overall, 60 CI users (92.3%) demonstrated improvement beyond cMDC at 12 months post-CI for at least 1 CIQOL-35 domain, and no patients' scores declined beyond cMDC for any domain. The percentage of CI users demonstrating improvement beyond cMDC varied by domain, with communication (53 [81.5%]) showing the largest number of CI users improving, followed by global (42 [64.6%]) and entertainment (40 [60.9%]). In general, CI users who demonstrated improvement in CIQOL-35 domains had greater improvement in speech recognition scores than patients who did not, but the strength and significance of these associations greatly varied by domain and speech material. Conclusions and Relevance: This multistep cohort study found that cMDC values for the CIQOL-35 Profile provided personalized thresholds for detecting real changes in patient self-reported functional abilities over time across multiple domains, which may inform clinical decision-making. Moreover, these longitudinal results reveal the domains with more or less improvement, which may aid in patient counseling.

Accurate phenotypic classification and exome sequencing allow identification of novel genes and variants associated with adult-onset hearing loss.

Adult-onset progressive hearing loss is a common, complex disease with a strong genetic component. Although to date over 150 genes have been identified as contributing to human hearing loss, many more remain to be discovered, as does most of the underlying genetic diversity. Many different variants have been found to underlie adult-onset hearing loss, but they tend to be rare variants with a high impact upon the gene product. It is likely that combinations of more common, lower impact variants also play a role in the prevalence of the disease. Here we present our exome study of hearing loss in a cohort of 532 older adult volunteers with extensive phenotypic data, including 99 older adults with normal hearing, an important control set. Firstly, we carried out an outlier analysis to identify genes with a high variant load in older adults with hearing loss compared to those with normal hearing. Secondly, we used audiometric threshold data to identify individual variants which appear to contribute to different threshold values. We followed up these analyses in a second cohort. Using these approaches, we identified genes and variants linked to better hearing as well as those linked to worse hearing. These analyses identified some known deafness genes, demonstrating proof of principle of our approach. However, most of the candidate genes are novel associations with hearing loss. While the results support the suggestion that genes responsible for severe deafness may also be involved in milder hearing loss, they also suggest that there are many more genes involved in hearing which remain to be identified. Our candidate gene lists may provide useful starting points for improved diagnosis and drug development.

Potential Clinical and Economic Outcomes of Over-the-Counter Hearing Aids in the US.

Importance: Over-the-counter (OTC) hearing aids are now available in the US; however, their clinical and economic outcomes are unknown. Objective: To project the clinical and economic outcomes of traditional hearing aid provision compared with OTC hearing aid provision. Design, Setting, and Participants: This cost-effectiveness analysis used a previously validated decision model of hearing loss (HL) to simulate US adults aged 40 years and older across their lifetime in US primary care offices who experienced yearly probabilities of acquiring HL (0.1%-10.4%), worsening of their HL, and traditional hearing aid uptake (0.5%-8.1%/y at a fixed uptake cost of $3690) and utility benefits (0.11 additional utils/y). For OTC hearing aid provision, persons with perceived mild to moderate HL experienced increased OTC hearing aid uptake (1%-16%/y) based on estimates of time to first HL diagnosis. In the base case, OTC hearing aid utility benefits ranged from 0.05 to 0.11 additional utils/y (45%-100% of traditional hearing aids), and costs were $200 to $1400 (5%-38% of traditional hearing aids). Distributions were assigned to parameters to conduct probabilistic uncertainty analysis. Intervention: Provision of OTC hearing aids, at increased uptake rates, across a range of effectiveness and costs. Main Outcomes and Measures: Lifetime undiscounted and discounted (3%/y) costs and quality-adjusted life-years (QALYs) and incremental cost-effectiveness ratios (ICERs). Results: Traditional hearing aid provision resulted in 18.162 QALYs, compared with 18.162 to 18.186 for OTC hearing aids varying with OTC hearing aid utility benefit (45%-100% that of traditional hearing aids). Provision of OTC hearing aids was associated with greater lifetime discounted costs by $70 to $200 along with OTC device cost ($200-$1000/pair; 5%-38% traditional hearing aid cost) due to increased hearing aid uptake. Provision of OTC hearing aids was considered cost-effective (ICER<$100 000/QALY) if the OTC utility benefit was 0.06 or greater (55% of the traditional hearing aid effectiveness). In probabilistic uncertainty analysis, OTC hearing aid provision was cost-effective in 53% of simulations. Conclusions and Relevance: In this cost-effectiveness analysis, provision of OTC hearing aids was associated with greater uptake of hearing intervention and was cost-effective over a range of prices so long as OTC hearing aids were greater than 55% as beneficial to patient quality of life as traditional hearing aids.

Why Do Candidates Forgo Cochlear Implantation?

OBJECTIVE: Identify barriers and facilitating factors in cochlear implant (CI) utilization by comparing functional measures between CI candidates who undergo or forgo implantation. METHODS: Forty-three participants were separated into two groups: (1) 28 participants who underwent CI and (2) 15 participants who elected not to proceed with CI despite meeting eligibility criteria (no-CI). Prior to implantation, all participants completed the CI Quality of Life (CIQOL)-35 Profile and CIQOL-Expectations instrument. They were also surveyed on factors contributing to their decision to either undergo or forgo CI. Word and speech recognition were determined using the Consonant-Nucleus-Consonant (CNC) and the AzBio tests, respectively. RESULTS: CIQOL-Expectations scores were indistinguishable between groups, but there were substantial differences in baseline CIQOL-35 Profile scores. Compared to the CI group, the no-CI group exhibited higher pre-CI scores in the Emotional (Cohen's d [95% CI] = 0.8 [0.1, 1.5]) and Entertainment (Cohen's d [95% CI] = 0.8 [0.1, 1.5]) domains. Survey data revealed that the most commonly reported barriers to pursuing CI in the no-CI cohort were fear of surgical complications (85%), cost associated with implantation (85%), and perception that hearing was not poor enough for CI surgery (85%). CONCLUSIONS AND RELEVANCE: The results of this study indicate that functional outcome expectations are similar between candidates who elect to receive or forgo CI, yet those who forgo CI have higher baseline CI-specific QOL abilities. LEVEL OF EVIDENCE: 4 Laryngoscope, 133:3548-3553, 2023.

Recognition of spectrally shaped speech in speech-modulated noise: Effects of age, spectral shape, speech level, and vocoding.

This study examined the recognition of spectrally shaped syllables and sentences in speech-modulated noise by younger and older adults. The effect of spectral shaping and speech level on temporal amplitude modulation cues was explored through speech vocoding. Subclinical differences in hearing thresholds in older adults were controlled using threshold matching noise. Older, compared to younger, adults had poorer recognition but similar improvements as the bandwidth of the shaping function increased. Spectral shaping may enhance the sensation level of glimpsed speech, which improves speech recognition in noise, even with mild elevations in hearing thresholds.

Probability Distributions for Associations Between Cognitive Screening and Pure-tone Thresholds in Older Adults.

OBJECTIVES: Lower general cognitive function is frequently reported in older adults with elevated pure-tone thresholds. Here, we examined reason(s) for this association, including whether this relationship is dependent on the frequency range or extent of hearing loss and cognitive screening performance. DESIGN: Linear regression was used to examine associations between better-ear pure-tone thresholds and Mini-Mental Status Exam (MMSE) performance in a cross-sectional sample of relatively healthy older adults (N = 508; 68% women, 60-89+ years; M age = 72). Quantile regression was also used to identify the ranges of 0.5 and 4.0 kHz thresholds and MMSE scores where these variables exhibited significant associations. RESULTS: MMSE scores and pure-tone thresholds exhibited small but significant associations, particularly for better-ear 0.5 kHz thresholds. This hearing threshold and cognitive screening association was present among participants with better hearing, including the oldest older adults. There was limited evidence for mediating health condition effects on this association. An item analysis of the MMSE revealed that the MMSE and pure-tone threshold associations were largely due to the delayed recall item of the MMSE. CONCLUSIONS: Together, the small effect results are consistent with the extant literature and suggest that there are multiple reasons for modest pure-tone threshold and cognitive screening performance associations.