Association of skin color, race/ethnicity, and hearing loss among adults in the USA

"Close to My Community": A Qualitative Study of Community Health Worker-Supported Teleaudiology Hearing Aid Services

OBJECTIVES

Given well-documented disparities in rural and minority communities, alternative service delivery models that help improve access to hearing care are needed. This article reports on a study of older Latino adults with hearing loss who received hearing aid services with Community Health Workers (CHWs) providing support via teleaudiology. The present study used qualitative data to explore perceptions of this novel service delivery model.

DESIGN

Participants completed semistructured interviews related to their experiences in the intervention approximately 17 weeks after the hearing aid fitting appointment. Two coders independently coded the data, using an iterative deductive and inductive thematic analysis approach. Inter-rater reliability was good (κ = 0.80).

RESULTS

Of the 28 participants, 19 were interviewed (CHW group: n = 9, 8 females; non-CHW group: n = 10, 9 females). Both groups of participants reported experiencing barriers in access to care and reported positive experiences with teleaudiology and with hearing aids as part of the trial. CHW group participants reported interactions with patient-site facilitators that were indicative of patient-centeredness.

CONCLUSIONS

Results demonstrate the feasibility and potential effectiveness of trained CHWs as patient-site facilitators in teleaudiology-delivered hearing aid services for adults.

National Cohort Data Suggests an Association Between Serious Mental Illness and Audiometric Hearing Loss

OBJECTIVE

To explore whether there is an association between serious mental illness (SMI) and hearing loss (HL) among US Hispanic adults.

STUDY DESIGN AND SETTING

Cross-sectional epidemiological study (Hispanic Community Health Study), including multicentered US volunteers.

METHODS

Multivariable linear regressions were conducted to study the association between SMI and HL. Adjustments were made for potential confounders including age, sex, education, vascular disease (hypertension or diabetes mellitus), and cognition. SMI was defined by (1) antipsychotic medication classification and (2) the use of at least 1 antipsychotic medication specifically used to treat SMI in clinical psychiatric practice. HL was measured by pure tone audiometry.

RESULTS

A total of 7581 subjects had complete data. The mean age was 55.2 years (SD = 7.5 years) and the mean pure tone average in the better ear was 16.8 dB (SD = 10.7 dB). A total of 194 (2.6%) subjects were taking a HCHS-defined antipsychotic and 98 (1.3%) were taking at least 1 antipsychotic specifically used to treat SMI. On multivariable regression, use of HCHS's classified antipsychotics was associated with 3.75 dB worse hearing (95% confidence interval [CI] = 2.36-5.13, P < .001) and use of antipsychotics specific for SMI was associated with 4.49 dB worse hearing (95% CI = 2.56-6.43, P < .001) compared to those not using antipsychotics.

CONCLUSION

SMI, as defined by either the use of HCHS-defined antipsychotics or the use of antipsychotic medication specific for SMI, is associated with worse hearing, controlling for potential confounders. Whether SMI contributes to HL, antipsychotic medication (through ototoxicity) contributes to HL, or whether HL contributes to SMI is unknown and warrants further investigation.

Demographic factors impact the rate of hearing decline across the adult lifespan

BACKGROUND

Little is known about the natural history of hearing loss in adults, despite it being an important public health problem. The purpose of this study is to describe the rate of hearing change per year over the adult lifespan.

METHODS

The 1436 participants are from the MUSC Longitudinal Cohort Study of Age-related Hearing Loss (1988-present). Outcomes are audiometric thresholds at 250, 500, 1000, 2000, 3000, 4000, 6000, and 8000 Hz, averaged across right and left ears, and pure-tone average (PTA). Demographic factors are sex (female/male), race, which is categorized as white or racial Minority, and baseline age group (18-39, 40-59, 60-69, 70+ years). Linear mixed regression models are used to estimate the effect of age (per year) on the rate of threshold and PTA change.

RESULTS

Participants' mean age is 63.1 (SD 14.9) years, 57.7% are female, and 17.8% are racial Minority (17.1% were Black or African American). In sex-race-adjusted models, rates of threshold change are 0.42 to 1.44 dB across thresholds. Rates of change differ by sex at most individual thresholds, but not PTA. Females (versus males) showed higher rates of threshold change in higher frequencies but less decline per year in lower frequencies. Black/African American (versus white) participants have lower rates of threshold and PTA change per year. Hearing thresholds decline across the adult lifespan, with older (versus younger) baseline age groups showing higher rates of decline per year.

CONCLUSIONS

Declines to hearing occur across the adult lifespan, and the rate of decline varies by sex, race, and baseline age.

Melanometry for objective evaluation of skin pigmentation in pulse oximetry studies

Pulse oximetry enables real-time, noninvasive monitoring of arterial blood oxygen levels. However, results can vary with skin color, thus detecting disparities during clinical validation studies requires an accurate measure of skin pigmentation. Recent clinical studies have used subjective methods such as self-reported color, race/ethnicity to categorize skin. Melanometers based on optical reflectance may offer a more effective, objective approach to assess pigmentation. Here, we review melanometry approaches and assess evidence supporting their use as clinical research tools. We compare performance data, including repeatability, robustness to confounders, and compare devices to each other, to subjective methods, and high-quality references. Finally, we propose best practices for evaluating melanometers and discuss alternate optical approaches that may improve accuracy. Whilst evidence indicates that melanometers can provide superior performance to subjective approaches, we encourage additional research and standardization efforts, as these are needed to ensure consistent and reliable results in clinical studies.

Agreement between audiometric hearing loss and self-reported hearing difficulty on the Revised Hearing Handicap Inventory differs by demographic factors

BACKGROUND

New standardised measures of self-reported hearing difficulty can be validated against audiometric hearing loss. This study reports the influence of demographic factors (age, sex, race and socioeconomic position (SEP)) on the agreement between audiometric hearing loss and self-reported hearing difficulty.

METHODS

Participants were 1558 adults (56.9% female; 20.0% racial minority; mean age 63.7 (SD 14.1) years) from the Medical University of South Carolina Longitudinal Cohort Study of Age-Related Hearing Loss (1988-current). Audiometric hearing loss was defined as the average of pure-tone thresholds at frequencies 0.5, 1.0, 2.0 and 4.0 kHz >25 dB HL in the worse ear. Self-reported hearing difficulty was defined as ≥6 points on the Revised Hearing Handicap Inventory (RHHI) or RHHI screening version (RHHI-S). We report agreement between audiometric hearing loss and the RHHI(-S), defined by sensitivity, specificity, accuracy, positive predictive value, negative predictive value and observed minus predicted prevalence. Estimates were stratified to age group, sex, race and SEP proxy.

RESULTS

The prevalence of audiometric hearing loss and self-reported hearing difficulty were 49.0% and 48.8%, respectively. Accuracy was highest among participants aged <60 (77.6%) versus 60-70 (71.4%) and 70+ (71.9%) years, for white (74.6%) versus minority (68.0%) participants and was similar by sex and SEP proxy. Generally, agreement of audiometric hearing loss and RHHI(-S) self-reported hearing difficulty differed by age, sex and race.

CONCLUSIONS

Relationships of audiometric hearing loss and self-reported hearing difficulty vary by demographic factors. These relationships were similar for the full (RHHI) and screening (RHHI-S) versions of this tool.

Serum Prestin Level May Increase Following Music Exposure That Induces Temporary Threshold Shifts: A Pilot Study

OBJECTIVES

To determine if blood prestin level changes after exposure to music at high sound pressure levels, and if this change is associated with temporary threshold shift (TTS) and/or changes in distortion product (DP) amplitude.

DESIGN

Participants were exposed to pop-rock music at 100 dBA for 15 min monaurally through headphones. Pure-tone audiometry, DP amplitude, and blood prestin level were measured before and after exposure.

RESULTS

Fourteen adults (9 women; age range: 20 to 54 years, median age = 31 [Interquartile ratio = 6.75]) with normal hearing were included in the study. Mean prestin level increased shortly after exposure to music, then returned to baseline within 1 week, although this trend was not observed in all participants. All participants presented TTS or a decrease in DP amplitude in at least one frequency after music exposure. There was a statistically significant average threshold elevation at 4 min postexposure. Statistically significant DP amplitude shifts were observed at 4 and 6 kHz, 2 min following exposure. Mean baseline serum prestin level (mean: 140.00 pg/mL, 95% confidence interval (CI): 125.92 to 154.07) progressively increased following music exposure, reaching a maximum at 2 hr (mean: 158.29 pg/mL, 95% CI: 130.42 to 186.66) and returned to preexposure level at 1 week (mean: 139.18 pg/mL, 95% CI: 114.69 to 163.68). However, after correction for multiple comparisons, mean prestin level showed no statistically significant increase from baseline at any timepoint. No correlation between maximum blood prestin level change and average TTS or distortion product otoacoustic emission amplitude shift was found. However, in an exploratory analysis, TTS at 6 kHz (the frequency at which maximum TTS occurred) decreased significantly as baseline blood prestin level increased.

CONCLUSIONS

The results suggest that blood prestin level may change after exposure to music at high sound pressure levels, although statistical significance was not reached in this relatively small sample after correction. Baseline serum prestin level may also predict the degree of TTS. These findings thus suggest that the role of baseline serum prestin level as a proxy marker of cochlear susceptibility to intense music exposure should be further explored.

Social Determinants of Health and Hearing Loss in U.S. Adults

OBJECTIVES

Social determinants of health (SDH) are nonmedical, societal factors that influence health. There is limited information on the current relationship between SDH and hearing loss (HL) in the United States. This study aims to compare the odds of HL among US adults by race/ethnicity, education level, income-to-poverty level ratio, health insurance coverage, and health care access.

STUDY DESIGN

Cross-sectional study.

METHODS

The 2015-2020 National Health and Nutrition Examination Survey data were analyzed to compare odds ratios (ORs) for HL, defined as pure tone average over 25 dB HL in at least one ear, by SDH categories using sample weights. Adjusted ORs were calculated using logistic regression models controlling for sex, age, race/ethnicity, education level, income-to-federal-poverty level, health care insurance coverage and access, and loud noise, pesticide, and cigarette exposure.

RESULTS

A total of 6028 participants were included. Non-Hispanic Black participants had half the odds of HL as Non-Hispanic White participants (OR 0.52, p < 0.05). Lower education level correlated with higher odds of HL: those without a high school diploma had double the odds of HL compared with college graduates or above (OR 2.05, 1.91, p < 0.05). The income-to-federal-poverty level ratio of 1.3 to less than 2 had higher odds of HL than the 4+ group (OR 1.45, p < 0.05). Use of multiple health care locations was associated with nearly three times the odds of HL than the group using one location (OR 2.87, p < 0.05).

CONCLUSION

SDH are associated with HL. Further investigation is needed into the mechanism of disparities for targeted prevention and treatment for hearing care equity.

LEVEL OF EVIDENCE

IV Laryngoscope, 134:2848-2856, 2024.

The association between ultra-processed food intake and age-related hearing loss: a cross-sectional study

OBJECTIVES

This study aimed to explore the association between ultra-processed foods and age-related hearing loss.

METHODS

Cross-sectional analyses based on data from a nationally representative sample of 1075 adults aged over 50 in the US was performed. The odds ratios (ORs) and 95% confidence intervals (CIs) for hearing loss according to ultra-processed foods intake quartiles were calculated using a multiple adjusted logistic regression model. Restricted cubic spline model was used to flexibly model potential nonlinear relations between ultra-processed foods intake and possibility of hearing loss. We also explored statistical interactions and conducted subgroup analyses where they were found to be significant.

RESULTS

Ultra-processed foods intake was significantly correlated with high-frequency hearing loss. After controlling for all covariables, individuals in the fourth quartile of Ultra-processed foods consumption had a 2.8 times higher chance of developing high-frequency hearing loss than individuals in the first quartile of Ultra-processed foods consumption. We also found that the association was more significant in non-Hispanic whites.

CONCLUSIONS

This study discovered an association between Ultra-processed foods intake and the incidence of high-frequency hearing loss, which was more significant in non-Hispanic whites.

The Stria Vascularis: Renewed Attention on a Key Player in Age-Related Hearing Loss

Age-related hearing loss (HL), or presbycusis, is a complex and heterogeneous condition, affecting a significant portion of older adults and involving various interacting mechanisms. Metabolic presbycusis, a type of age-related HL, is characterized by the dysfunction of the stria vascularis, which is crucial for maintaining the endocochlear potential necessary for hearing. Although attention on metabolic presbycusis has waned in recent years, research continues to identify strial pathology as a key factor in age-related HL. This narrative review integrates past and recent research, bridging findings from animal models and human studies, to examine the contributions of the stria vascularis to age-related HL. It provides a brief overview of the structure and function of the stria vascularis and then examines mechanisms contributing to age-related strial dysfunction, including altered ion transport, changes in pigmentation, inflammatory responses, and vascular atrophy. Importantly, this review outlines the contribution of metabolic mechanisms to age-related HL, highlighting areas for future research. It emphasizes the complex interdependence of metabolic and sensorineural mechanisms in the pathology of age-related HL and highlights the importance of animal models in understanding the underlying mechanisms. The comprehensive and mechanistic investigation of all factors contributing to age-related HL, including cochlear metabolic dysfunction, remains crucial to identifying the underlying mechanisms and developing personalized, protective, and restorative treatments.

New Paradigm of Music Listening: Hearing Protection Perceptions and Treatment Decision-Making Among Music Venue Attendees

OBJECTIVE

Investigate the prevalence of hearing protection (HP) use and behavioral motivations and barriers among adults attending music venues.

STUDY DESIGN

Cross-sectional online survey study.

SETTING

Noise exposure levels at popular social music venues often exceed national guidelines.

METHODS

Surveys were distributed on online music communities. Respondents (n = 2352) were asked about demographics, HP use at music venues, knowledge about noise exposure impact, and perceptions of HP use. Data were characterized through descriptive statistics. Multivariable regression analysis explored differences in knowledge and perception between HP users and nonusers.

RESULTS

In this cohort (mean age 29 ± 7 years, 61% male), HP users were significantly more aware of the impact of music venues on hearing (P < .01), believed their hearing ability had decreased after attending music venues (P < 0.01), and believed HP could protect from hearing loss (P < .01) than non-HP users. HP nonusers most frequently cited never considering HP (14.45%) and apathy about it affecting music quality (12.71%). Common sources of HP information were recommended by a friend/peer. Multivariable regression analysis accounting for demographics, medical history, and attendance characteristics found belief that HP use at music venues could protect from hearing loss (β = 0.64, 95% confidence interval [CI] = [0.49-0.78]) and HP use (β = 1.73, 95% CI = [1.47-1.98]) were significantly associated with increased subjective enjoyment while wearing HP.

CONCLUSION

HP users and nonusers have significantly different perceptions of HP use and its impact. Our findings have implications for understanding motivations and barriers related to HP use and developing strategies to promote HP use at music venues.

Association between blood volatile organic aromatic compound concentrations and hearing loss in US adults

OBJECTIVE

Benzene, ethylbenzene, meta/para-xylene, and ortho-xylene, collectively referred to as benzene, ethylbenzene, and xylene (BEX), constitute the main components of volatile organic aromatic compounds (VOACs) and can have adverse effects on human health. The relationship between exposure to BEX and hearing loss (HL) in the adult U.S. population was aimed to be assessed.

METHODS

Cross-sectional data from the National Health and Nutrition Examination Survey (NHANES) for the years 2003-2004, 2011-2012, and 2015-2016 were analyzed. This dataset included complete demographic characteristics, pure-tone audiometry measurements, and volatile organic compound detection data from the NHANES database. A weighted multivariate logistic regression model was employed to investigate the associations between blood BEX concentrations HL, low-frequency hearing loss (SFHL), and high-frequency hearing loss (HFHL).

RESULTS

2174 participants were included, with weighted prevalence rates of HL, SFHL, and HFHL being 46.81%, 25.23%, and 45.86%, respectively. Exposure to benzene, ethylbenzene, meta/para-xylene, and ortho-xylene, and cumulative BEX concentrations increased the risk of hearing loss (odds ratios [ORs] were 1.36, 1.22, 1.42, 1.23, and 1.31, respectively; all P < 0.05). In the analysis with SFHL as the outcome, ethylbenzene, m-/p-xylene, o-xylene, benzene, and overall BEX increased the risk (OR 1.26, 1.21, 1.28, 1.20, and 1.25, respectively; all P < 0.05). For HFHL, exposure to ethylbenzene, m-/p-xylene, o-xylene, benzene, and overall BEX increased the risk (OR 1.36, 1.22, 1.42, 1.22, and 1.31, respectively; all P < 0.05).

CONCLUSION

Our study indicated that a positive correlation between individual or cumulative exposure to benzene, ethylbenzene, meta/para-xylene, and ortho-xylene and the risk of HL, SFHL, and HFHL. Further research is imperative to acquire a more comprehensive understanding of the mechanisms by which organic compounds, notably BEX, in causing hearing loss and to validate these findings in longitudinal environmental studies.

Risk-taking propensity as a risk factor for noise-induced hearing loss in the general population

OBJECTIVES

To examine general risk propensity in relation to perceptions of noise, risk behaviour, and hearing loss in the general population.

DESIGN

Participants completed an online survey using the Amazon Mechanical Turk crowdsourcing platform.

STUDY SAMPLE

The sample comprised 1274 adults from the United States.

RESULTS

Higher general risk propensity was associated with an increased likelihood to engage in noise-risk behaviours. Lower general risk propensity was associated with increased knowledge of noise risks and an increased perception of noise as risky. The frequency of self-reported exposures to hazardous noise resulted in estimated annual noise doses exceeding standard hazard limits in 40% of the surveyed population.

CONCLUSIONS

Results revealed limited knowledge of the risks and associated health consequences of noise exposure in the general population Results of this study suggest a high rate of self-exposure to hazardous noise by the general population. Those with higher general risk propensity are more likely to engage in risky noise behaviour. Risky noise behaviour is associated with age, gender, race, ethnicity, and general risk propensity. Intervention programs to modify risky noise behaviour in the general population should focus on both increasing knowledge and establishing accurate perceptions of risk.

Association of coffee consumption with the prevalence of hearing loss in US adults, NHANES 2003-2006

OBJECTIVE

This study aims to explore the association between coffee consumption and the prevalence of hearing loss in American adults based on a national population-based survey.

DESIGN

Cross-sectional analysis of reported audiometric status and coffee intake from the 2003-2006 National Health and Nutrition Examination Survey (NHANES). Multivariate logistic regression, forest plots and restricted cubic spline (RCS) analyses were used to explore the associations and dose-response relationships between coffee consumption frequency and hearing loss.

SETTING

The USA.

PARTICIPANT

This study included 1894 individuals aged ≥ 20 from the 2003-2006 NHANES.

RESULTS

In this study, the prevalence of speech-frequency hearing loss (SFHL) and high-frequency hearing loss (HFHL) among the participants was 35·90 % and 51·54 %, respectively. Compared with those who no consumed coffee, non-Hispanic White who consumed ≥ 4 cups/d had higher prevalence of SFHL (OR: 1·87; 95 % CI: 1·003. 3·47). And a positive trend of coffee consumption frequency with the prevalence of HFHL was found (Ptrend = 0·001). This association of HFHL was similar for participants aged 20-64 (Ptrend = 0·001), non-Hispanic White (Ptrend = 0·002), non-noise exposure participants (Ptrend = 0·03) and noise-exposed participants (Ptrend = 0·003). The forest plots analysis found that the association between 1 cup-increment of daily coffee consumption and the prevalence of HFHL was statistically significant in males. RCS model supported a positive linear association of coffee consumption with SFHL (P for overall association = 0·02, P for nonlinearity = 0·48) and a positive non-linear association of coffee consumption with HFHL (P for overall association = 0·001, P for nonlinearity = 0·001).

CONCLUSION

Our findings suggested that coffee consumption was associated with higher prevalence of hearing loss. Further cohort studies in larger population are needed to investigate these findings.

Hearing, β-Amyloid Deposition and Cognitive Test Performance in Black and White Older Adults: The ARIC-PET Study

BACKGROUND

Hearing loss is a risk factor for dementia; whether the association is causal or due to a shared pathology is unknown. We estimated the association of brain β-amyloid with hearing, hypothesizing no association. As a positive control, we quantified the association of hearing loss with neurocognitive test performance.

METHODS

Cross-sectional analysis of Atherosclerosis Risk in Communities-Positron Emission Tomography study data. Amyloid was measured using global cortical and temporal lobe standardized uptake value ratios (SUVRs) calculated from florbetapir-positron emission tomography scans. Composite global and domain-specific cognitive scores were created from 10 neurocognitive tests. Hearing was measured using an average of better-ear air conduction thresholds (0.5-4 kHz). Multivariable-adjusted linear regression estimated mean differences in hearing by amyloid and mean differences in cognitive scores by hearing, stratified by race.

RESULTS

In 252 dementia-free adults (72-92 years, 37% Black race, and 61% female participants), cortical or temporal lobe SUVR was not associated with hearing (models adjusted for age, sex, education, and APOE ε4). Each 10 dB HL increase in hearing loss was associated with a 0.134 standard deviation lower mean global cognitive factor score (95% CI: -0.248, -0.019), after adjustment for demographic and cardiovascular factors. Observed hearing-cognition associations were stronger in Black versus White participants.

CONCLUSIONS

Amyloid is not associated with hearing, suggesting that pathways linking hearing and cognition are independent of this pathognomonic Alzheimer's-related brain change. This is the first study to show that the impact of hearing loss on cognition may be stronger in Black versus White adults.

The association of sex steroid hormone concentrations with hearing loss: a cross-sectional study

BACKGROUND

Hearing loss is the most prevalent sensory disorder worldwide. Several studies have indicated that sex steroid hormone levels may be vital to hearing.

OBJECTIVE

We aimed to explore the associations between speech-frequency hearing loss and sex steroid hormones.

METHODS

We conducted a secondary analysis based on 3558 adult participants' data from the National Health and Nutrition Examination Survey (NHANES) from 2015 to 2016. We defined hearing loss as a pure-tone average (PTA) at 0.5, 1, 2, and 4 kHz ≥20 dB in the better ear. Multivariate logistic regression analysis was used to evaluate the association between sex steroid hormones and hearing loss risk. A nomogram model for the risk of hearing loss was constructed.

RESULTS

There were 560 (15.7%) cases who had hearing loss among the participants enrolled in this study. Participants with hearing loss had a higher total testosterone level and a lower estradiol level. Individuals with estradiol levels in the highest tertile still had lower hearing loss risks than those in the lowest tertile. Nevertheless, the total testosterone level had no influence on the risk of hearing loss.

CONCLUSION

Our research indicated that low estradiol concentrations were significantly associated with hearing loss, especially in menopausal women.

Sex and Race Representation in Temporal Bone Histopathology Studies in the United States: A Systematic Review

OBJECTIVES

The author's objective was to evaluate sex and race representation in temporal bone histopathology studies.

DESIGN

PubMed, Embase, Cochrane, Web of Science, and Scopus were searched for studies written in English examining temporal bone histopathology specimens from U.S.-based institutions from January 1, 1947, to September 1, 2021. Two authors then performed "snowballing" by reviewing references from the initial search and included the studies that fulfilled the inclusion criteria. For each study, the following information was collected: publication details, study design, funding, institution from where temporal bone specimens were procured, number of study specimens, and donor demographical information.

RESULTS

The authors found that out of 300 studies, 166 (55%) report sex while only 15 (5%) reported race information. Over the past 70 years, the ratio of studies reporting sex to those that do not has increased from 1.00 to 2.19 and the number of female temporal bone histopathology subjects relative to male has increased from 0.67 to 0.75. Over 90% of studies that do report this information feature participant racial compositions that do not reflect the diversity of the U.S. population.

CONCLUSIONS

Studies of temporal bone histopathology often do not report participant sex or race. The reporting of participant sex and the inclusion of specimens from female donors have both increased over time. However, temporal bone histopathology study cohorts are not representative of the racial diversity of the U.S. population. The otolaryngology community must strive to build temporal bone histopathology libraries that are representative of the diverse U.S. population.

Associations among Visual, Auditory, and Olfactory Functions in Community-Based Older Adults: The Atherosclerosis Risk in Communities (ARIC) Study

PURPOSE

Objective examination of relationships among visual, hearing, and olfactory function may yield mechanistic insights and inform our understanding of the burden of multiple-sensory impairments.

METHODS

This cross-sectional study capitalized on continuous measures of visual acuity (VA), contrast sensitivity, pure tone audiometry, Quick Speech-in-Noise (QuickSIN), and Sniffin' Sticks from a subset of ARIC participants at two community sites (EyeDOC Study, 2017-2019). Scales of all measures were aligned such that higher values indicated greater impairment. Intersensory bivariate associations were assessed graphically, and correlations assessed using Kendall's tau. Intersensory associations, independent of age, education, smoking, diabetes, and hypertension, were examined using linear regression. Analyses were stratified by community/race (Washington County/White vs Jackson/Black) and sex (men vs women) to explore community-sex heterogeneity.

RESULTS

We included 834 participants (mean age, 79 years); 39% were from Jackson and 63% females. We found weak intersensory correlations (tau generally ≤0.15). In the demographics-adjusted regression models, results were heterogeneous across communities and sex. Worse near VA, contrast sensitivity, and olfaction were associated with worse QuickSIN and worse near VA was associated with worse olfaction in some but not all community/race-sex groups (e.g., Jackson/Black women, 0.1 logMAR worse near VA was associated with 0.27 units increase in QuickSIN [95% confidence interval, 0.10-0.45]). Associations were modestly attenuated by adjustment for the shared risk factors of smoking, diabetes, and hypertension.

CONCLUSIONS

Visual dysfunction showed little or no association with hearing or olfaction impairments, suggesting a modest role for shared risk factors.

TRANSLATIONAL RELEVANCE

Visually impaired individuals have only a modestly higher risk of other sensory impairment.

Understanding the Relationship Between Age-Related Hearing Loss and Alzheimer’s Disease: A Narrative Review

Evidence suggests that hearing loss (HL), even at mild levels, increases the long-term risk of cognitive decline and incident dementia. Hearing loss is one of the modifiable risk factors for dementia, with approximately 4 million of the 50 million cases of dementia worldwide possibly attributed to untreated HL. This paper describes four possible mechanisms that have been suggested for the relationship between age-related hearing loss (ARHL) and Alzheimer’s disease (AD), which is the most common form of dementia. The first mechanism suggests mitochondrial dysfunction and altered signal pathways due to aging as a possible link between ARHL and AD. The second mechanism proposes that sensory degradation in hearing impaired people could explain the relationship between ARHL and AD. The occupation of cognitive resource (third) mechanism indicates that the association between ARHL and AD is a result of increased cognitive processing that is required to compensate for the degraded sensory input. The fourth mechanism is an expansion of the third mechanism, i.e., the function and structure interaction involves both cognitive resource occupation (neural activity) and AD pathology as the link between ARHL and AD. Exploring the specific mechanisms that provide the link between ARHL and AD has the potential to lead to innovative ideas for the diagnosis, prevention, and/or treatment of AD. This paper also provides insight into the current evidence for the use of hearing treatments as a possible treatment/prevention for AD, and if auditory assessments could provide an avenue for early detection of cognitive impairment associated with AD.

Foundational Approaches to Advancing Hearing Health Equity: A Primer in Social Epidemiology

Hearing health is inextricably linked to factors beyond biology. Social, demographic, environmental, geographic, and historical influences affect hearing health, but these factors are often unmeasured within traditional biological, clinical, and epidemiological studies of hearing health. With increasing recognition of hearing health over the life course as a public health priority, there is also a growing understanding of existing hearing health inequities at the individual, community, national, and global levels. To make progress in addressing these inequities, public health disciplines, such as social epidemiology, can provide valuable frameworks. With a focus on integrating the biological and functional with social and structural factors influencing health, social epidemiology provides key concepts and approaches for filling existing research and practice gaps. In this review, we introduce the discipline of social epidemiology and its associated concepts to inspire greater cross-disciplinary collaboration for the ultimate goal of advancing hearing health equity.

The audiogram: Detection of pure-tone stimuli in ototoxicity monitoring and assessments of investigational medicines for the inner ear

Pure-tone thresholds have long served as a gold standard for evaluating hearing sensitivity and documenting hearing changes related to medical treatments, toxic or otherwise hazardous exposures, ear disease, genetic disorders involving the ear, and deficits that develop during aging. Although the use of pure-tone audiometry is basic and standard, interpretation of thresholds obtained at multiple frequencies in both ears over multiple visits can be complex. Significant additional complexity is introduced when audiometric tests are performed within ototoxicity monitoring programs to determine if hearing loss occurs as an adverse reaction to an investigational medication and during the design and conduct of clinical trials for new otoprotective agents for noise and drug-induced hearing loss. Clinical trials using gene therapy or stem cell therapy approaches are emerging as well with audiometric outcome selection further complicated by safety issues associated with biological therapies. This review addresses factors that must be considered, including test-retest variability, significant threshold change definitions, use of ototoxicity grading scales, interpretation of early warning signals, measurement of notching in noise-induced hearing loss, and application of age-based normative data to interpretation of pure-tone thresholds. Specific guidance for clinical trial protocols that will assure rigorous methodological approaches and interpretable audiometric data are provided.

Prevalence of Self-Reported Hearing Loss and Associated Risk Factors: Findings From the Survey of the Health of Wisconsin

PURPOSE

The purpose of this study was to determine the prevalence of self-reported hearing loss and associated risk factors in a representative population-based study of Wisconsin residents.

METHOD

Survey of the Health of Wisconsin participants with data on self-reported hearing loss were included. We reported prevalence of self-reported hearing loss with corresponding 95% confidence intervals (CIs), overall, and stratified by age and sex. Age- and sex-adjusted and multivariable logistic regression models were used to evaluate determinants of self-reported hearing loss, and results are presented as odds ratios with corresponding 95% CIs.

RESULTS

There were 2,767 participants (50.7% men) with a mean age of 46 years (range: 21-74) in this study. Prevalence of self-reported hearing loss was 26.8% (24.4, 28.4) and was higher in men (30.3% [27.1, 33.4]) than in women (22.5% [19.9, 25.0]). Prevalence increased with age. After multivariable adjustment, age (per +1 year increase; 1.05 [1.04, 1.06]), male sex (1.57 [1.18, 2.08]), having two chronic diseases (vs. 0; 1.93 [1.16, 3.23]), occupational (2.47 [1.91, 3.19]) and recreational (1.58 [1.22, 2.04]) noise exposure, and poor diet (1.88 [1.28, 2.78]) were associated with higher odds of self-reported hearing loss.

CONCLUSIONS

Hearing loss is a highly prevalent public health concern and may be at least partially modifiable via interventions to reduce noise exposure and promote health. Statewide prevalence and risk factor data can be used to inform public health practice and promote hearing loss prevention.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.19661130.

Racial and Ethnic Differences in Hearing Aid Use Among Medicare Beneficiaries

OBJECTIVES

We examined individual-level factors associated with hearing aid use by race and ethnicity in a nationally representative sample of Medicare beneficiaries.

METHODS

We used the Medicare Current Beneficiary Survey (cycles 2016-2018) for 10,301 older adults with hearing loss and hearing aid use as the primary outcome. Covariates included education, income, urban residence, chronic conditions, functional limitations, and Medicaid eligibility. Multivariable logistic regression stratified by race and ethnicity was used to identify factors associated with hearing aid use.

RESULTS

Factors associated with hearing aid use included higher education among White (OR = 1.35, 95%CI:1.16, 1.58), Black (OR = 1.76, 95%CI:1.02, 3.05), and Hispanic (OR = 1.77, 95%CI:1.17, 2.68) beneficiaries. Urban residence was associated with hearing aid use for Black participants (OR = 3.06, 95%CI:1.17, 8.03) and Medicaid eligibility for Hispanic participants (OR = 1.58, 95%CI:0.97, 2.59), although the confidence interval included the null hypothesis.

DISCUSSION

ndividual-level factors associated with hearing aid use differed by race and ethnicity among Medicare beneficiaries.

Hearing Function, Degeneration, and Disease: Spotlight on the Stria Vascularis

The stria vascularis (SV) is a highly vascularized tissue lining the lateral wall of the cochlea. The SV maintains cochlear fluid homeostasis, generating the endocochlear potential that is required for sound transduction. In addition, the SV acts as an important blood-labyrinth barrier, tightly regulating the passage of molecules from the blood into the cochlea. A healthy SV is therefore vital for hearing function. Degeneration of the SV is a leading cause of age-related hearing loss, and has been associated with several hearing disorders, including Norrie disease, Meniere's disease, Alport syndrome, Waardenburg syndrome, and Cytomegalovirus-induced hearing loss. Despite the SV's important role in hearing, there is still much that remains to be discovered, including cell-specific function within the SV, mechanisms of SV degeneration, and potential protective or regenerative therapies. In this review, we discuss recent discoveries elucidating the molecular regulatory networks of SV function, mechanisms underlying degeneration of the SV, and otoprotective strategies for preventing drug-induced SV damage. We also highlight recent clinical developments for treating SV-related hearing loss and discuss future research trajectories in the field.

Central Auditory Processing and the Relationship to Perceived Hearing Difficulty: The Jackson Heart Study

OBJECTIVE

There are limited population-based studies of central auditory processing (CAP). We aimed to determine the relationship between CAP measures and perceived hearing difficulty (PHD) despite normal pure-tone audiometry in an African-American population.

STUDY DESIGN

Cross-sectional.

SETTING

Jackson Heart Study (JHS), Jackson, MS.

SUBJECTS

Participants of an African-American cohort (26% men; age 54.2, standard deviations [SD] 9.2) who self-reported hearing difficulty despite normal hearing sensitivity defined as audiometric pure-tone average (PTA-4: average of 500, 1000, 2000, and 4000 Hz) less than or equal to 25 dBHL (n = 911) or across all tested frequencies (PT-AF: 250-8000 Hz) less than or equal to 25 dBHL (n = 516).

METHODS

The Quick Speech-in-Noise (QuickSIN) and Dichotic Digits, Double Pairs (DDT2) tests were used to assess CAP. Logistic regression was used to examine the association between measures of CAP and PHD; adjusted for age, sex, education, and pure tone audiogram.

RESULTS

PHD was present in 251 (28%) and 137 (27%) of participants using the PTA-4 and PT-AF models, respectively. Fully adjusted regression models revealed that each one-point increase in QuickSIN increased the odds of reporting PHD by 13.7% (odds ratio [OR] 1.14, p < 0.01, 95% CI: 1.08, 1.19) using the PTA-4 model and 15.0% (OR 1.15, p < 0.01, 95% CI: 1.08, 1.23) using the PT-AF model. For DDT2 testing, each 1% reduction in score, increased the odds of reporting PHD by 7.7% (OR 0.92, p < 0.01, 95% CI: 0.88, 0.97) in a fully adjusted PTA-4 model and 6.6% (OR 0.93, p = 0.04, 95% CI: 0.87, 0.99) in the PT-AF model.

CONCLUSION

CAP deficits were associated with increased odds of PHD in normal hearing participants within the JHS cohort.

Free Energy and Stacking of Eumelanin Nanoaggregates

Eumelanin, a member of the melanin family, is a black-brown insoluble pigment. It possesses a broad range of properties such as antioxidation, free radical scavenging, photoprotection, and charge carrier transportation. Surprisingly, the exact molecular structure of eumelanin remains undefined. It is, however, generally considered to consist of two main building blocks, 5,6-dihydroxyindole (DHI) and 5,6- dihydroxyindole carboxylic acid (DHICA). We focus on DHI and report, for the first time, a computational investigation of the structural properties of DHI-eumelanin aggregates in aqueous solutions. First, multimicrosecond molecular dynamics (MD) simulations at different concentrations were performed to investigate the aggregation and ordering of tetrameric DHI-eumelanin protomolecules. This was followed by umbrella sampling (US) and density functional theory (DFT) calculations to study the physical mechanisms of stacking. Aggregation occurs through formation of nanoscale stacks and was observed in all systems. Further analyses showed that aggregation and coarsening of the domains is due to a decrease in hydrogen bonds between the eumelanins and water; while domains exist, there is no long-range order. The results show noncovalent stacks with the interlayer distance between eumelanin protomolecules being less than 3.5 Å. This is in good agreement with transmission electron microscopy data. Both free energy calculations and DFT revealed strong stacking interactions. The electrostatic potential map provides an explanation and a rationale for the slightly sheared relative orientations and, consequently, for the curved shapes of the nanoscale domains.

Black Older Americans Have Lower Prevalence of Hearing Loss Than Their White Peers: Findings From Two Large Nationally Representative Surveys

PURPOSE

The purpose of this study was to investigate Black-White differences associated with hearing loss among older adults living in the United States.

METHOD

Secondary data analysis was conducted using the 2017 American Community Survey (ACS) with a replication analysis of the 2016 ACS. The ACS is an annual nationally representative survey of Americans living in community settings and institutions. The sample size of older Americans (age 65+ years) in 2017 was 467,789 non-Hispanic Whites (NHWs) and 45,105 non-Hispanic Blacks (NHBs). In the 2016 ACS, there were 459,692 NHW and 45,990 NHB respondents. Measures of hearing loss, age, race/ethnicity, education level, and household income were based on self-report. Data were weighted to adjust for nonresponse and differential selection probabilities.

RESULTS

The prevalence of hearing loss was markedly higher among older NHWs (15.4% in both surveys) in comparison with NHBs (9.0% in 2017 and 9.4% in 2016, both ethnic differences p < .001). In the 2017 ACS, the age- and sex-adjusted odds of hearing loss were 69% higher for NHWs compared with NHBs, which increased to 91% higher odds when household income and education level were also taken into account (OR = 1.91; 95% confidence interval [CI; 1.85, 1.97]). Findings from the 2016 ACS were very similar (e.g., 65+ fully adjusted OR = 1.81; 95% CI [1.76, 1.87]).

CONCLUSIONS

NHWs have a much higher prevalence and almost double the odds of hearing loss compared with NHBs. Unfortunately, the ACS survey does not allow us to explore potential causal mechanisms behind this association.

The Role of Eye Color in the Emergence of Tinnitus in Silence

Introduction  Previous research suggests that African Americans are less likely than Caucasians to perceive tinnitus in sustained silence.

Objective  To evaluate the association between non-cutaneous melanin as indicated by eye color and the emergence of temporary tinnitus during a brief period of silence.

Methods  A cross-section of adults grouped according to their eye color were exposed to silence. A total of 62 adults, aged 18 to 35 years (10 males, 52 females) were required to sit in silence for 10 minutes, after which they filled out a questionnaire to report their eye color and any perception of sounds in the ears or head.

Results  In total, 63% of the participants perceived tinnitus while sitting in silence, and, of these 95% perceived the tinnitus sounds within 5 minutes of sitting in silence. Though African Americans were less likely to perceive tinnitus in silence, this difference was not significant ( p  = 0.6). After a period of silence, 69% of the subjects with light-colored eyes and 58% of the dark-eyed subjects perceived tinnitus. This difference was not statistically significant (χ ² (1) = 0.77; p  = 0.38).

Conclusion  When exposed to reduced auditory stimulation, 3 out of 5 normal-hearing people are likely to experience tinnitus. However, there was no relationship between eye color and the perception of tinnitus in silence. Although melanin has been shown to play a role in the protection of the ear against noise trauma and the effects of age-related hearing loss, its role in the emergence of tinnitus needs further investigation.

Extended High-frequency Hearing Impairment Despite a Normal Audiogram: Relation to Early Aging, Speech-in-noise Perception, Cochlear Function, and Routine Earphone Use

OBJECTIVES

Humans can hear up to 20 kHz. Emerging evidence suggests that hearing in the extended high frequencies (EHFs; >8 kHz) contributes to speech perception in noise. The objective of the present study was to describe the features of EHF hearing impairment in young adults with normal standard audiograms (0.25-8 kHz). Specifically, the study goals were to: (1) characterize the EHF hearing impairment and identify potential risk factors; (2) elucidate the age-related changes in EHF hearing; (3) determine the effect of EHF hearing impairment on speech-in-noise recognition; and (4) examine the extent to which EHF hearing impairment influences cochlear functioning in the standard frequencies.

DESIGN

Hearing thresholds at standard frequencies and EHFs (10, 12.5, 14, and 16 kHz), and speech recognition thresholds (SRTs) using digit triplets in multi-talker babble were measured in both ears from 222 participants (19-38 years; n = 444 ears) with normal audiograms (≤20 dB HL at standard frequencies). Test-retest measurement of hearing thresholds was obtained in a subset of 50 participants (100 ears), and clinical distortion product otoacoustic emissions (f2 frequency = 2, 3, 4, and 5 kHz) were recorded in 49 participants (98 ears).

RESULTS

Forty-two of 222 participants had EHF hearing impairment (>20 dB HL for at least one EHF in either ear). Only seven individuals with EHF impairment had significant case history and/or listening-in-noise complaints. A breakpoint in the threshold-age function was observed for the EHFs for males but not for females. Linear mixed models revealed a significant effect of age, pure-tone averages for speech frequencies (0.5, 1, 2, and 4 kHz), and EHFs and group (NH versus EHF hearing impairment) independent of each other on the SRTs. Individuals with EHF hearing impairment had less measurable emissions and when present, had a lower magnitude of otoacoustic emissions relative to NH controls. There was no difference in hearing thresholds, SRTs, or otoacoustic emissions between earphone users and nonusers.

CONCLUSIONS

The hearing thresholds for the EHFs exhibit signs of early auditory aging. Age-related deterioration in auditory function can be observed in the third decade of human life. A breakpoint in the threshold-age function suggests that rapid aging processes are operational at a relatively younger age (21 years) for males. The audibility of EHFs contributes to speech-in-noise recognition. EHF hearing impairment independent of age and speech frequencies can affect speech-in-noise recognition. Reduced distortion product otoacoustic emissions in the standard frequencies may suggest preclinical cochlear degeneration in individuals with EHF hearing impairment.

Patterns of Prevalence of Multiple Sensory Impairments among Community-Dwelling Older Adults

BACKGROUND

Much is known about individual sensory deficits among older adults, but there is a dearth of information about the prevalence of multiple concurrent sensory deficits in this population.

METHODS

We evaluated the prevalence of individual and multiple sensory impairments at the most recent clinic visit among participants aged 24 years and older in the Baltimore Longitudinal Study of Aging (BLSA) (hearing, vision, olfaction, proprioception, and vestibular function) and Atherosclerosis Risk in Communities Study (ARIC) (hearing, vision, olfaction). We compared observed prevalence of multiple sensory impairments with expected prevalence based on compounded probabilities of multiple impairments using Fisher Exact Tests. Also, we evaluated the comparability of different measures used between these two studies.

RESULTS

In both studies, the prevalence of each individual sensory impairment was common (>10%), and higher with older age, and the most common pattern of co-occurring sensory impairments was hearing and visual impairments (17.4% [BLSA]; 50.2% [ARIC]). In BLSA, the pattern that differed the most between observed and expected prevalence was combined hearing, vision, and olfactory impairments (observed 5.2% vs. 1.4% expected, p=0.01). In ARIC, this difference was much smaller (observed 8.1% vs. 7.2% expected, p=0.49).

CONCLUSIONS

Although concurrent hearing and vision impairments were the most common co-occurring deficits, combined hearing, vision and olfactory impairments are most likely to co-occur above chance, especially at older ages.

Health Disparities in Otology: A PRISMA-Based Systematic Review

OBJECTIVE

Social determinants of health (SDOHs), including but not limited to sex, race, socioeconomic status, insurance status, and education level, play a significant role in health disparities and affect health outcomes. The purpose of this systematic review is to examine health disparities in otology within the United States and highlight areas warranting further research.

DATA SOURCES

PubMed, Ovid MEDLINE.

REVIEW METHODS

Our search encompassed all years through January 10, 2021. All peer-reviewed primary literature of any design and publication date regarding health disparities and otology outcomes in the United States was eligible for inclusion. Eligibility assessment was performed via 3 independent investigators.

RESULTS

Of the 6326 unique abstracts identified, 188 studies underwent full-text review, and 52 remained in the final review. The most frequently examined otologic condition was hearing loss (36.5%), followed by cochlear implantation (28.8%) and infection/effusion (15.4%). Vertigo/dizziness (1.9%), Ménière's disease (1.9%), and tinnitus (1.9%) were the least represented otologic conditions. Comprehensive articles on multiple disparity topics were the most common (n = 18), followed by articles on race/ethnicity (n = 11) and socioeconomic status (n = 9). Language (n = 2), education (n = 2), and gender (n = 1) were the least discussed. Over 5-fold the number of articles were published between 2011 and 2020 compared to the preceding decade (42 vs 8).

CONCLUSION

This study captures the existing literature regarding health disparities and outcomes in otology. The lack of robust data suggests the need for future quality studies aimed at investigating disparities in otologic care, as well as a broader push for recording and reporting SDOHs.

Modeling individual noise-induced hearing loss risk with proxy measurements of external-ear amplification

Significant variability in noise-induced hearing loss (NIHL) susceptibility suggests there are factors beyond sound level and duration of exposure that contribute to individual susceptibility. External-ear amplification (EEA) from external-ear structures varies significantly due to ear size and shape, potentially influencing NIHL susceptibility. This study tested the hypothesis that EEA can be predicted using non-technical proxy measurements including pinna height (cm), body height (m), and earcanal volume (cm³). 158 participants (4-78 years) completed otoscopy, tympanometry, pinna measurements, body height measurements, and two EEA measurements: (1) total real-ear unaided gain (REUG) of the open ear and (2) real-ear to coupler difference (RECD), representing unaided gain from the earcanal. Participants' individual noise doses were compared in hypothetical exposures. REUG ranged from 5 to 19 dBA and was correlated with pinna height. High-REUG participants were estimated to accrue noise doses at least 5 times higher than low-REUG participants. RECD ranged from 7 to 24 dBA and was correlated with earcanal volume and body height. The results support the hypothesis that EEA measurement could significantly improve estimation of an individual's position along the NIHL risk spectrum. Non-technical proxy measurements of EEA (pinna height, body height, earcanal volume) were statistically significant but yielded high variability in individual EEA prediction.

Association of Poorer Hearing With Longitudinal Change in Cerebral White Matter Microstructure

Importance

There is a dearth of studies that examine the association between poorer hearing and change in cerebral white matter (WM) microstructure.

Objective

To examine the association of poorer hearing with baseline and change in WM microstructure among older adults.

Design, Setting, and Participants

This was a prospective cohort study that evaluated speech-in-noise, pure-tone audiometry, and WM microstructure, as measured by mean diffusivity (MD) and fractional anisotropy (FA), both of which were evaluated by diffusion tensor imaging (DTI) in 17 WM regions. Data were collected between October 2012 and December 2018 and analyzed between March 2019 and August 2019 with a mean follow-up time of 1.7 years. The study evaluated responses to the Baltimore Longitudinal Study of Aging among 356 cognitively normal adults who had at least 1 hearing assessment and DTI session. Excluded were those with baseline cognitive impairment, stroke, head injuries, Parkinson disease, and/or bipolar disorder.

Exposures

Peripheral auditory function was measured by pure-tone average in the better-hearing ear. Central auditory function was measured by signal-to-noise ratio score from a speech-in-noise task and adjusted by pure-tone average.

Main Outcomes and Measures

Linear mixed-effects models with random intercepts and slopes were used to examine the association of poorer peripheral and central auditory function with baseline and longitudinal DTI metrics in 17 WM regions, adjusting for baseline characteristics (age, sex, race, hypertension, elevated total cholesterol, and obesity).

Results

Of 356 cognitively normal adults included in the study, the mean (SD) age was 73.5 (8.8) years, and 204 (57.3%) were women. There were no baseline associations between hearing and DTI measures. Longitudinally, poorer peripheral hearing was associated with increases in MD in the inferior fronto-occipital fasciculus (β = 0.025; 95% CI, 0.008-0.042) and the body (β = 0.050; 95% CI, 0.015-0.085) of the corpus callosum, but there were no associations of peripheral hearing with FA changes in these tracts. Poorer central auditory function was associated with longitudinal MD increases (β = 0.031; 95% CI, 0.010-0.052) and FA declines (β = -1.624; 95% CI, -2.511 to -0.738) in the uncinate fasciculus.

Conclusions and Relevance

Findings of this cohort study suggest that poorer hearing is related to change in integrity of specific WM regions involved with auditory processing.

Comparison of Age-Related Pigmentary Changes in the Auditory and Vestibular Systems Within Mouse and Human Temporal Bones

Background

Melanin pigmentation is present within the auditory and vestibular systems of the mammalian inner ear and may play a role in maintaining auditory and vestibular function. Melanocytes within the stria vascularis (SV) are necessary for the generation of the endocochlear potential (EP) and decreased EP has been linked to age-related hearing loss. Melanocytes and pigment-containing "dark cells" are present within the vestibular system, but have a less well-defined role. African-American individuals have increased pigmentation within the SV and vestibular system, which is hypothesized to be related to lower rates of age-related hearing loss and vestibular dysfunction. It remains unclear if increased pigmentation confers lifelong protection against hearing loss and vestibular dysfunction.

Methods

Mouse temporal bones were collected from juvenile (3-4 week) and aged (20-32 months) CBA/CaJ mice. Pediatric and adult human temporal bones from Caucasian or African-American individuals were examined from the Johns Hopkins Temporal Bone Collection. Information regarding Fitzpatrick skin type were unavailable, and self-identified race/ethnicity was used as a proxy. Images were taken using light microscopy at 20× magnification. ImageJ software (v1.53) was used to measure pigment within the SV and vestibular system.

Results

In mouse temporal bones pigmentation within the SV increased with age, but pigmentation within the vestibular system did not increase with age. In human temporal bones pigmentation within the SV increased with age and pigmentation within the vestibular system increased within the wall of the utricle, but not other regions of the vestibular system. African-American individuals had higher amounts of pigment within the SV and vestibular system, among both pediatric and adult populations.

Conclusion

Stria vascularis pigmentation increases with age in mouse and human temporal bones. Pigmentation within the vestibular system did not increase with age in mouse specimens and only increased within the utricular wall with age in human specimens. Individuals who identified as African-American had higher pigment content within the SV and vestibular system, both as children and as adults. These results highlight how similar age-related pigmentary changes occur in the auditory and vestibular systems across species and underscore the importance of racial/ethnic diversity in human temporal bone studies.

Hearing impairment in military personnel in Eastern Saudi Arabia

BACKGROUND:

Noise exposure is one of the most common occupational hazards worldwide. Studies have shown that the prevalence of hearing loss and tinnitus is higher in military personnel than in other occupations. This study aimed to estimate the prevalence of hearing impairment in military personnel in Eastern Saudi Arabia.

MATERIALS AND METHODS:

A cross-sectional study was conducted among 409 military personnel. A self-administered questionnaire collected data on level of awareness, hearing impairment, and protection of hearing. Pure-tone audiometry (PTA) was conducted on 141 participants to determine the prevalence and pattern of hearing impairment. Multivariate analysis was used to determine the predictors of hearing loss in military personnel.

RESULTS:

More than half of the participants (54.3%) were unaware of the consequences of noise exposure and none used proper hearing protection. A small percentage (5.9%) complied with the annual hearing examination, and only 23% had had a previous hearing evaluation. More than half of the participants (58.4%) had one or more abnormal hearing-related symptoms, with tinnitus as the most common symptom (43.8%). PTA showed hearing impairment in 71.6% of the participants. Multivariate analysis showed older age as only significant factor associated with hearing impairment in military personnel.

CONCLUSION:

Noise-induced hearing loss and tinnitus are common occupational disabilities in military personnel. Hearing conservation programs have to be initiated to ensure the application of hearing protection measures and control the effects of exposure to noise.

Demographic and Socioeconomic Disparities in Life Expectancy With Hearing Impairment in the United States

OBJECTIVES

Hearing impairment is one of the most common disabilities among older people, and its prevalence will increase as the U.S. population ages. However, little is known about social disparities in onset or transitions into and out of hearing impairment, nor how these transitions impact years of life to be spent impaired.

METHOD

We investigate the number of years an "average" person can expect to live with and without hearing impairment after age 50; sex, race, educational, and regional differences in these expectancies; and the implication of hearing impairment for remaining life expectancy. Bayesian multistate life table methods are applied to 9 waves of data from the Health and Retirement Study (1998-2014) to investigate social disparities in life expectancy with hearing impairment (n = 20,200) for the general population, people hearing impaired at age 50, and people hearing unimpaired at age 50.

RESULTS

Men, Hispanics, persons with less educational attainment, and those born in the south can expect to live a larger proportion of their remaining lives hearing impaired. Although transitions from hearing impaired to unimpaired occur, those with some hearing impairment at age 50 can expect to live more years with hearing impairment, and hearing impairment does not shorten remaining life expectancy.

DISCUSSION

Significant sociodemographic disparities in hearing impaired life expectancy exist. In contrast to past research, we find that hearing impairment does not affect total life expectancy. Future research should consider the consequences of hearing impairment for years to be lived with other age-related and potentially downstream health outcomes.

Trends in Cochlear Implantation in Texas: An Exploration of Outpatient Discharge Data, 2010 to 2017

OBJECTIVES

To describe trends in cochlear implantation (CI) disparities in Texas using an all-payer database from 2010 to 2017.

METHODS

Texas Outpatient Surgical and Radiological Procedure Data, a public use data file, was accessed to analyze outpatient CI cases for Texas. Variables analyzed include patient age, sex, race/ethnicity, and insurance status. Population data from the American Community Survey generated CI utilization rates by patient demographic characteristics.

RESULTS

There were 6158 CI cases identified during the study period. The number of CI per year nearly doubled from 497 in 2010 to 961 in 2017. The majority of CI recipients were white (59.5%), male (51.9%), and privately insured (47.9%). All sub-populations statewide had more CI in 2017 compared to 2010, with the overall CI per 100 000 population increasing from 1.98 to 3.50 per 100 000 population. Patients over 75 demonstrated the greatest increase in the CI rate per 100 000 population, increasing from 4.60 in 2010 to 14.30 in 2017. Regarding race/ethnicity, all sub-populations noted an increase in the CI per 100 000 population, with white patients demonstrating the highest rate in 2017, at 4.36 CI per 100 000 population. Asian patients had a 502% increase in the CI rate (from 0.42 to 2.53), compared with 87.9%, 84.4%, and 69.2% increases for white, Black, and Hispanic populations, respectively.

CONCLUSIONS

CI became more widespread between 2010 and 2017, benefiting certain populations more than others. Black and Hispanic populations had lower CI per 100 000 population than their white peers, while patients >65 years of age accounted for the greatest increase in CI.

Loud Music and Leisure Noise Is a Common Cause of Chronic Hearing Loss, Tinnitus and Hyperacusis

High sound levels capable of permanently damaging the ear are experienced not only in factories and war zones but in concert halls, nightclubs, sports stadiums, and many other leisure environments. This review summarizes evidence that loud music and other forms of "leisure noise" are common causes of noise-induced hearing loss, tinnitus, and hyperacusis, even if audiometric thresholds initially remain within clinically normal limits. Given the huge global burden of preventable noise-induced hearing loss, noise limits should be adopted in a much broader range of settings, and education to promote hearing conservation should be a higher public health priority.

Modeling Hearing Loss Progression and Asymmetry in the Older Old: A National Population-Based Study

OBJECTIVE

The progression and asymmetry of age-related hearing loss has not been well characterized in those 80 years of age and older because public datasets mask upper extremes of age to protect anonymity. We aim to characterize the progression, severity, and asymmetry of hearing loss in those 80 years of age and older using a representative, national database.

METHODS

Cross-sectional, multicentered U.S. epidemiologic analysis using the National Health and Nutrition Examination Survey (NHANES) 2005 to 2006, 2009 to 2010, and 2011 to 2012 cycles. Subjects included noninstitutionalized, civilian adults aged 80 years and older (n = 621). Federal security clearance was granted to access publicly restricted age data. Outcome measures included pure-tone average (PTA) air conduction thresholds and the 4-frequency PTA.

RESULTS

Six hundred and twenty-one subjects were 80 years old or older (mean = 84.2 years, range = 80-104 years), representing 10,600,197 Americans. The average PTA was 38.9 dB (95% confidence interval [CI] = 37.8, 40.0). Hearing loss exhibited constant acceleration across the adult lifespan at a rate of 0.0052 dB/year2 (95% CI = 0.0049, 0.0055). This model predicted mean PTA within 2 dB of accuracy for most ages between 20 and 100 years. From age 80 years to approximately 100 years, the average PTA difference between the better and worse ear was 6.75 dB (95% CI = 5.8, 7.1). This asymmetry was relatively constant (i.e., nonsignificant linear regression coefficient of asymmetry over age = 0.07 [95% CI = -0.01, 0.2]).

CONCLUSION

Hearing loss steadily and predictably accelerates across the adult lifespan to at least age 100 years, becoming near universal. These population-level statistics will guide treatment and policy recommendations for hearing health in the older old.

LEVEL OF EVIDENCE

3 Laryngoscope, 131:879-884, 2021.

The Neuromelanin Paradox and Its Dual Role in Oxidative Stress and Neurodegeneration

Aging is associated with an increasing dysfunction of key brain homeostasis mechanisms and represents the main risk factor across most neurodegenerative disorders. However, the degree of dysregulation and the affectation of specific pathways set apart normal aging from neurodegenerative disorders. In particular, the neuronal metabolism of catecholaminergic neurotransmitters appears to be a specifically sensitive pathway that is affected in different neurodegenerations. In humans, catecholaminergic neurons are characterized by an age-related accumulation of neuromelanin (NM), rendering the soma of the neurons black. This intracellular NM appears to serve as a very efficient quencher for toxic molecules. However, when a neuron degenerates, NM is released together with its load (many undegraded cellular components, transition metals, lipids, xenobiotics) contributing to initiate and worsen an eventual immune response, exacerbating the oxidative stress, ultimately leading to the neurodegenerative process. This review focuses on the analysis of the role of NM in normal aging and neurodegeneration related to its capabilities as an antioxidant and scavenging of harmful molecules, versus its involvement in oxidative stress and aberrant immune response, depending on NM saturation state and its extracellular release.

CYP1A1 and GSTs common gene variations and presbycusis risk: a genetic association analysis and a bioinformatics approach

Antioxidant enzymes such as glutathione S-transferases (GSTs) and cytochromes P450 (CYPs) are involved in the metabolism and detoxification of cytotoxic compounds, as well as the elimination of reactive oxygen species (ROS). Therefore, alterations in the structure of these enzymes could result in prolonged production of ROS with subsequent risk of development of disorders such as presbycusis. This study aimed to investigate the association between CYP1A1 (rs4646903, rs1048943) and GSTs (GSTM1-deletion, GSTT1-deletion, GSTP1-rs1695) with presbycusis risk in an Iranian population which was followed by an in silico approach. In a case-control study, 280 subjects including 140 cases with presbycusis and 140 healthy controls were enrolled. Genotypes of single-nucleotide polymorphisms (SNPs) were detected by PCR-RFLP method and the genotype of the above mentioned deletions was determined by touchdown PCR. Some bioinformatics tools were employed to evaluate the impact of SNPs on the gene function. SNP analysis revealed that there are significant associations between rs1048943 (AG vs. AA: OR = 2.46, 95%CI = 1.30-4.65, p = 0.006; GG + AG vs. AA: OR = 2.53, 95%CI = 1.36-4.69, p = 0.003; G vs. A: OR = 2.36, 95%CI = 1.33-4.17, p = 0.003) and rs4646903 (C vs. T: OR = 1.45, 95%CI = 1.02-2.06, p = 0.040) variations and increased risk of presbycusis. However, there was no significant association between rs1695 and presbycusis risk. Also, significant associations were observed between GSTM1 (OR = 4.28, 95%CI = 1.18-15.52, p = 0.027) and GSTT1 (OR = 1.64, 95%CI = 1.02-2.65, p = 0.041) deletions and elevated risk of presbycusis. Moreover, the combination analysis revealed a significant association between GSTM1+/GSTT1- genotype and presbycusis susceptibility (OR = 1.63, 95%CI = 1.00-2.67, p = 0.049). In silico analysis revealed that the rs1048943 SNP could influence significantly on the RNA structure of CYP1A1 (distance: 0.1454; p value: 0.1799). Based on our findings, the rs4646903, rs1048943 SNPs as well as GSTM1 and GSTT1 deletions could be considered as genetic risk factors for the development and progression of presbycusis.

Racial Capitalism Within Public Health-How Occupational Settings Drive COVID-19 Disparities

Epidemiology of the US coronavirus disease 2019 (COVID-19) outbreak focuses on individuals’ biology and behaviors, despite centrality of occupational environments in the viral spread. This demonstrates collusion between epidemiology and racial capitalism because it obscures structural influences, absolving industries of responsibility for worker safety. In an empirical example, we analyzed economic implications of race-based metrics widely used in occupational epidemiology. In the United States, White adults have better average lung function and worse hearing than Black adults. Impaired lung function and impaired hearing are both criteria for workers’ compensation claims, which are ultimately paid by industry. Compensation for respiratory injury is determined using a race-specific algorithm. For hearing, there is no race adjustment. Selective use of race-specific algorithms for workers’ compensation reduces industries’ liability for worker health, illustrating racial capitalism operating within public health. Widespread and unexamined belief in inherent physiological inferiority of Black Americans perpetuates systems that limit industry payouts for workplace injuries. We see a parallel in the epidemiology of COVID-19 disparities. We tell stories of industries implicated in the outbreak and review how they exemplify racial capitalism. We call on public health professionals to critically evaluate who is served and neglected by data analysis and to center structural determinants of health in etiological evaluation.

Twin study of neonatal transient-evoked otoacoustic emissions

Our knowledge of which physiological mechanisms shape transient evoked otoacoustic emissions (TEOAEs) is incomplete, although thousands of TEOAEs are recorded each day as part of universal newborn hearing-screening (UNHS). TEOAE heritability may explain some of the large TEOAE variability observed in neonates, and give insights into the TEOAE generators and modulators, and why TEOAEs are generally larger in females and right ears. The aim was to estimate TEOAE heritability and describe ear and sex effects in a consecutive subset of all twins that passed UNHS at the same occasion at two hospitals during a six-year period (more than 30 000 neonates screened in total). TEOAEs were studied and TEOAE level correlations compared in twin sets of same-sex (SS, 302 individual twins, 151 twin pairs) and opposite-sex (OS, 152 individual twins, 76 twin pairs). A mathematical model was used to estimate and compare monozygotic (MZ) and dizygotic (DZ) intra-twin pair TEOAE level correlations, based on the data from the SS and OS twin sets. For both SS and OS twin pairs TEOAE levels were significantly higher in right ears and females, compared to left ears and males, as previously demonstrated in young adult twins and large groups of neonates. Neonatal females in OS twin pairs did not demonstrate masculinized TEOAEs, as has been demonstrated for OAEs in young adult females in OS twin pairs. The within-twin pair TEOAE level correlations were higher for SS twin pairs than for OS twin pairs, whereas the within-pair correlation coefficients could not be distinguished from zero when twins were randomly paired. These results reflect heredity as a key factor in TEOAE level variability. Additionally, the estimated MZ within-twin pair TEOAE level correlations were higher than those for DZ twin pairs. The heritability estimates reached up to 100% TEOAE heritability, which is numerically larger than previous estimates of about 75% in young adult twins.

The Prevalence of Hearing, Vision, and Dual Sensory Loss in Older Canadians: An Analysis of Data from the Canadian Longitudinal Study on Aging

The purpose of this study was to describe the prevalence of hearing loss (HL), vision loss (VL), and dual sensory loss (DSL) in Canadians 45–85 years of age. Audiometry and visual acuity were measured. Various levels of impairment severity were described. Results were extrapolated to the 2016 Canadian population. In 2016, 1,500,000 Canadian males 45–85 years of age had at least mild HL, 1,800,000 had at least mild VL, and 570,000 had DSL. Among females, 1,200,000 had at least mild HL, 2,200,000 had at least mild VL, and 450,000 had DSL. Among Canadians 45–85 years of age, mild, moderate, and severe HL was prevalent among 13.4 per cent, 3.7 per cent, and 0.4 per cent of males, and among 11.3 per cent, 2.3 per cent, and 0.2 per cent of females, respectively. Mild and moderate, or severe VL was prevalent among 19.8 per cent and 2.4 per cent of males, and among 23.9 per cent and 2.6 per cent of females, respectively. At least mild DSL was prevalent among 6.4 per cent of males and 6.1 per cent of females.

Hearing handicap in Asian patients with dementia

BACKGROUND

Hearing loss and hearing handicap may contribute to cognitive impairment and dementia. The purpose of this study was to analyze the association between hearing loss and hearing handicap with dementia in an Asian memory clinic parents.

METHODS

This study includes the data obtained from patients with mild dementia who attended the National University hospital memory clinic and non-demented healthy subjects among spouses and caregivers who are non-genetically related to our patients. All participants underwent comprehensive physical, medical, neuropsychological and audiological assessments (i.e. pure tone audiometry - PTA). Disabling hearing loss was defined as a hearing loss of >40 dB in the better ear on PTA. Amsterdam Inventory for Auditory Disability and Handicap (AIADH) questionnaire was administered through the verbal interview to measure their hearing handicap score. Linear regression models were used to investigate the association between hearing loss and hearing handicap with dementia. Mean differences (β) with 95% confidence intervals (CI) were calculated.

RESULTS

91 participants (65-90 years old) were recruited for this study; 39 of them were patients with dementia and 52 were non-demented healthy controls. 48.7% of the patients with dementia had disabling hearing loss, which is higher than the non-demented controls (25.0%) (p = 0.019). The significant association between hearing handicap (as measured by AIADH) and dementia was observed, which was independent of demographic factors and audiology related history and PTA average (β = -6.40; 95% CI =0.11.99, -0.81, p = 0.025). There was no independent association between hearing loss and dementia (p > 0.05).

CONCLUSION

A significant association between hearing handicap and dementia was found. The mechanism of this association requires further research and may involve higher order central processing disorder.

Noise-dose estimated with and without pre-cochlear amplification

Amplification from natural ear canal resonance has been documented as highly variable across individuals. However, individual variability in total pre-cochlear amplification (i.e., combined external and middle ear mechanisms) remains understudied in relevance to noise-induced hearing loss (NIHL). It is well-known that more noise means more risk of hearing loss, yet the current risk-models do not consider individually variable pre-cochlear amplification, also referred to as the transfer function of the open ear (TFOE). The present study principally documented individual TFOE variability and explored the feasibility and accuracy of simple proxy metrics, which could be used to estimate TFOE. Participants' TFOE values were used to estimate their NIHL risk in hypothetical free-field exposures. Forty-eight adult participants (42 female, 6 male, ages 21-60 years) met inclusion criteria of 2 healthy pinnae and ear canals (<10% cerumen occlusion) and type-A tympanometric examination. Participants underwent otoscopy, tympanometry, pinna size measurement, real-ear-to-coupler-difference, and TFOE measurement. TFOE ranged from 5 to 15 dB-A (mean = 10 dB-A); given that NIHL risk is estimated to double in either 3 or 5 dB-A increments, the observed variability could explain a substantial portion of individual vulnerability to NIHL. A simple regression model with eardrum compliance (ml) was correlated with individual TFOE (p < 0.05). TFOE variability has the potential to substantially explain why two individuals with the same noise-exposure can develop significantly different degrees of NIHL. Eardrum compliance (ml) was a correlated proxy measurement of TFOE in this principally adult, female dataset; additional research is needed to confirm this relationship in a unique, heterogeneous dataset.

Mouse methods and models for studies in hearing

Laboratory mice have become the dominant animal model for hearing research. The mouse cochlea operates according to standard "mammalian" principles, uses the same cochlear cell types, and exhibits the same types of injury as found in other mammals. The typical mouse lifespan is less than 3 years, yet the age-associated pathologies that may be found are quite similar to longer-lived mammals. All Schuknecht's types of presbycusis have been identified in existing mouse lines, some favoring hair cell loss while others favor strial degeneration. Although noise exposure generally affects the mouse cochlea in a manner similar to other mammals, mice appear more prone to permanent alterations to hair cells or the organ of Corti than to hair cell loss. Therapeutic compounds may be applied systemically or locally through the tympanic membrane or onto (or through) the round window membrane. The thinness of the mouse cochlear capsule and annular ligament may promote drug entry from the middle ear, although an extremely active middle ear lining may quickly remove most drugs. Preclinical testing of any therapeutic will always require tests in multiple animal models. Mice constitute one model providing supporting evidence for any therapeutic, while genetically engineered mice can test hypotheses about mechanisms.

Genome-wide association meta-analysis identifies five novel loci for age-related hearing impairment

Previous research has shown that genes play a substantial role in determining a person's susceptibility to age-related hearing impairment. The existing studies on this subject have different results, which may be caused by difficulties in determining the phenotype or the limited number of participants involved. Here, we have gathered the largest sample to date (discovery n = 9,675; replication n = 10,963; validation n = 356,141), and examined phenotypes that represented low/mid and high frequency hearing loss on the pure tone audiogram. We identified 7 loci that were either replicated and/or validated, of which 5 loci are novel in hearing. Especially the ILDR1 gene is a high profile candidate, as it contains our top SNP, is a known hearing loss gene, has been linked to age-related hearing impairment before, and in addition is preferentially expressed within hair cells of the inner ear. By verifying all previously published SNPs, we can present a paper that combines all new and existing findings to date, giving a complete overview of the genetic architecture of age-related hearing impairment. This is of importance as age-related hearing impairment is highly prevalent in our ageing society and represents a large socio-economic burden.

Advances in understanding of presbycusis

The pathophysiology of age-related hearing loss (ARHL), or presbycusis, involves a complex interplay between environmental and genetic factors. The fundamental biomolecular mechanisms of ARHL have been well described, including the roles of membrane transport, reactive oxygen species, cochlear synaptopathy, vascular insults, hormones, and microRNA, to name a few. The genetic basis underlying these mechanisms remains under-investigated and poorly understood. The emergence of genome-wide association studies has allowed for the identification of specific groups of genes involved in ARHL. This review highlights recent advances in understanding of the pathogenesis of ARHL, the genetic basis underlying these processes and suggests future directions for research and potential therapeutic avenues.