Age-Related Hearing Loss, Neuropsychological Performance, and Incident Dementia in Older Adults

Adult-onset hearing loss and incident cognitive impairment and dementia - A systematic review and meta-analysis of cohort studies

BACKGROUND

We comprehensively summarized the cohort evidence to date on adult-onset hearing loss as risk factor for incident cognitive impairment and dementia, and examined the evidence for dose-response, risk for various dementia subtypes, and other moderators. Previous meta-analyses were less comprehensive.

METHODS

We included cohort studies with participants without dementia and with hearing assessments at baseline, minimum 2 years follow-up and incident cognitive outcomes. We used random-effect models and subgroup and meta-regression on moderator analyses.

RESULTS

We identified fifty studies (N=1,548,754). Hearing loss (yes/no) was associated with incident dementia risk (HR=1.35 [95% CI = 1.26 - 1.45), mild cognitive impairment (MCI HR=1.29 [95% CI = 1.11 - 1.50]), cognitive decline not specified as MCI or dementia (HR=1.29 [95% CI = 1.17 - 1.42]), and Alzheimer's disease dementia (ADD, HR=1.56 [95% CI = 1.30 - 1.87]), but not with vascular dementia (HR, 1.30 [95% CI = 0.83 - 2.05]). Each 10-decibel worsening of hearing was associated with a 16% increase in dementia risk (95% CI = 1.07 - 1.27). The effect of hearing loss did not vary across potential moderators.

CONCLUSIONS

Cohort studies consistently support that adult-onset hearing loss increases the risk of incident cognitive decline, dementia, MCI, and ADD.

Subjective hearing loss is not associated with an increased risk of Alzheimer's disease dementia

Hearing loss is a risk-factor for dementia but the reasons for this are unclear. Subjective hearing loss is related to increased future dementia risk, however, this metric has not been previously examined with cognitive, neuroimaging and biochemical measures that are relevant to Alzheimer's disease. We assessed Cognitively Normal and Mild Cognitively Impaired participants from the Alzheimer's Disease Neuroimaging Initiative with subjective hearing loss to examine if they had faster decline in episodic memory scores, hippocampal volume and greater pTau positivity. The likelihood of a dementia diagnosis in hearing impaired participants over a 5-year period was also assessed. There were no statistically significant differences between the hearing subgroups over a 5-year period nor were there in conversions to a dementia diagnosis. Objective hearing loss metrics may provide a more reliable link between hearing loss and dementia risk.

Hearing Loss and Associated 7-Year Cognitive Outcomes Among Hispanic and Latino Adults

Importance

Hearing loss appears to have adverse effects on cognition and increases risk for cognitive impairment. These associations have not been thoroughly investigated in the Hispanic and Latino population, which faces hearing health disparities.

Objective

To examine associations between hearing loss with 7-year cognitive change and mild cognitive impairment (MCI) prevalence among a diverse cohort of Hispanic/Latino adults.

Design, Setting, and Participants

This cohort study used data from a large community health survey of Hispanic Latino adults in 4 major US cities. Eligible participants were aged 50 years or older at their second visit to study field centers. Cognitive data were collected at visit 1 and visit 2, an average of 7 years later. Data were last analyzed between September 2023 and January 2024.

Exposure

Hearing loss at visit 1 was defined as a pure-tone average (500, 1000, 2000, and 4000 Hz) greater than 25 dB hearing loss in the better ear.

Main outcomes and measures

Cognitive data were collected at visit 1 and visit 2, an average of 7 years later and included measures of episodic learning and memory (the Brief-Spanish English Verbal Learning Test Sum of Trials and Delayed Recall), verbal fluency (word fluency-phonemic fluency), executive functioning (Trails Making Test-Trail B), and processing speed (Digit-Symbol Substitution, Trails Making Test-Trail A). MCI at visit 2 was defined using the National Institute on Aging-Alzheimer Association criteria.

Results

A total of 6113 Hispanic Latino adults were included (mean [SD] age, 56.4 [8.1] years; 3919 women [64.1%]). Hearing loss at visit 1 was associated with worse cognitive performance at 7-year follow-up (global cognition: β = -0.11 [95% CI, -0.18 to -0.05]), equivalent to 4.6 years of aging and greater adverse change (slowing) in processing speed (β = -0.12 [95% CI, -0.23 to -0.003]) equivalent to 5.4 years of cognitive change due to aging. There were no associations with MCI.

Conclusions and relevance

The findings of this cohort study suggest that hearing loss decreases cognitive performance and increases rate of adverse change in processing speed. These findings underscore the need to prevent, assess, and treat hearing loss in the Hispanic and Latino community.

The Association between Untreated and Treated Hearing Loss and Cognitive Performance in Men and Women Aged 60-96 Years: Data from the Swedish "Good Aging in Skåne" Population Study

Background/Objectives: Recent decades have witnessed a sharp increase in research investigating the association between hearing loss and cognitive impairment. Few previous studies have stratified for sex when investigating this issue, where results were inconsistent and require further clarification. Thus, the objective was to investigate the association between self-reported hearing loss and levels of cognitive impairment, stratified for sex. Methods: In this cross-sectional study, data were collected from 2001 to 2016. The study sample consisted of 5075 individuals, 2325 (45.8%) men, mean age 68.3 years, and 2750 (54.2%) women, mean age 70.0 years. Multiple variate ordinal regression models were constructed and adjusted for age, marital status, education, physical activity, depressive mood, hypertension, stroke, diabetes, and use of sedatives to investigate associations between groups of self-reported untreated and treated hearing loss and those reporting no hearing loss in relation to levels of cognitive impairment assessed by the Mini-Mental State Examination scale. Results: In men, treated hearing loss was associated with levels of cognitive impairment, odds ratio (OR) = 1.64, 95% confidence interval (CI) = 1.14-2.36. In women, both untreated hearing loss, (OR = 1.45, CI 1.07-1.98) and treated hearing loss (OR= 1.46, CI 1.06-2.04) were associated with levels of cognitive impairment. Conclusions: Hearing loss was found to be associated with cognitive impairment despite hearing aid use as well as awareness amongst physicians. The introduction of screening programs for hearing loss in older adults could be a crucial step for earlier identification of individuals at higher risk of developing cognitive impairment and dementia.

Does Olfactory Training Improve Brain Function and Cognition? A Systematic Review

Olfactory training (OT), or smell training,consists of repeated exposure to odorants over time with the intended neuroplastic effect of improving or remediating olfactory functioning. Declines in olfaction parallel declines in cognition in various pathological conditions and aging. Research suggests a dynamic neural connection exists between olfaction and cognition. Thus, if OT can improve olfaction, could OT also improve cognition and support brain function? To answer this question, we conducted a systematic review of the literature to determine whether there is evidence that OT translates to improved cognition or altered brain morphology and connectivity that supports cognition. Across three databases (MEDLINE, Scopus, & Embase), 18 articles were identified in this systematic review. Overall, the reviewed studies provided emerging evidence that OT is associated with improved global cognition, and in particular, verbal fluency and verbal learning/memory. OT is also associated with increases in the volume/size of olfactory-related brain regions, including the olfactory bulb and hippocampus, and altered functional connectivity. Interestingly, these positive effects were not limited to patients with smell loss (i.e., hyposmia & anosmia) but normosmic (i.e., normal ability to smell) participants benefitted as well. Implications for practice and research are provided.

Association between cognitive dysfunction and diabetes in patients over 65 years old: a cross-sectional study using propensity score matching

OBJECTIVES

To investigate the association between diabetes and cognitive dysfunction in the elderly population, and examine the impact of cognitive dysfunction on level of activities of daily living (ADL) in patients with diabetes.

METHODS

Data analysis was conducted on 2,951 individuals aged over 65 years from the Chinese Longitudinal Healthy Longevity Survey cohort. Propensity score matching was utilized to mitigate selection bias. Multivariate binary logistic regression was performed to analyse the association between diabetes and cognitive dysfunction in the study subjects. In addition, the relationship between ADL and cognitive function in patients with diabetes was analysed using the Wilcoxon rank-sum test.

RESULTS

A significant association (p = 0.017) was found between diabetes and the occurrence of cognitive dysfunction in older adults. Subgroup analyses revealed that diabetes patients with cognitive dysfunction exhibited a worse ADL dependence compared with those without cognitive dysfunction (p < 0.001).

CONCLUSION

These findings indicate that diabetes is associated with cognitive dysfunction in older adults. Meanwhile, there is an association between cognitive impairment and ADL level in subjects with diabetes. As such, healthcare professionals should pay close attention to the occurrence of cognitive dysfunction and ADL decline during diagnosis and treatment, and proactive prevention and intervention strategies should be implemented.

Is Age a Limiting Factor for Audiological Results in Active Middle Ear Implants?

Active middle ear implants (AMEI) are implantable options for patients with sensorineural, conductive, or mixed hearing loss who are not good candidates for hearing aids. The aim of this study was to compare audiological, surgical, quality of life, and sound quality outcomes in adults <60 and ≥60 years receiving an AMEI. Twenty adult patients who underwent AMEI implantation were divided into two groups, <60 and ≥60 y. Preoperative tests included pure-tone average and speech discrimination score (SDS) at 65 dB for disyllabic words in quiet. Postoperative measures included AMEI-aided bone conduction threshold, free-field warble-tone threshold, and SDS at 65 dB for disyllabic words in quiet 12 months after the AMEI fitting. Subjective benefit was evaluated using the Nijmegen Cochlear Implant Questionnaire (NCIQ), Glasgow Benefit Inventory (GBI), and Hearing Implant Sound Quality Index (HISQUI19). Mean functional gain was 32 and 30 dB, and SDS at 65 dB improved from 19 to 95% and from 31 to 84% in the <60 and ≥60 y groups, respectively. All NCIQ domains improved following surgery, and all patients had a positive overall GBI score. The mean HISQUI19 score was 97 in both age groups. AMEIs are an effective hearing restoration method for older adults suffering from conductive or mixed hearing loss.

Association Between Hearing Loss and Multiple Negative Emotional States in the US Hispanic Population

OBJECTIVE

Hearing loss (HL) has been linked to commonly studied detrimental mood states, such as loneliness and depression. However, its relationship with other negative emotions remained largely unstudied. We explore the association between HL and anxiety, anger, hostility, poor self-esteem, and pessimism in a national cohort of US Hispanic adults.

STUDY DESIGN

Cross-sectional study.

SETTING

Multicentered US national epidemiologic study (Hispanic Community Health Study).

METHODS

Subjects were ages 18 to 75 with completed audiometric and emotional survey data. Multivariable regressions controlling for age, gender, and education were conducted to analyze the association between HL, measured by 4-frequency pure-tone average (PTA), and emotional states. States included anxiety (Spielberger Trait Anxiety Scale-10), anger (Spielberger Trait Anger Scale), hostility (Cook Medley Cynicism Scale-13), poor self-esteem (Self-Esteem Scale-10), and pessimism (Revised Life Orientation Test).

RESULTS

A total of 4120 to 4341 participants met inclusion criteria, depending on the specific survey; the average age was 46.7 years (standard deviation [SD] = 13.7), and the average PTA was 13.8 dB (SD = 10.1). Controlling for age, gender, and education, HL was associated with all outcomes. Specifically, for every 10 dB worsening in HL, the anxiety score worsened by 0.41 (0.23-0.60), the anger score worsened by 0.40 (0.22-0.58), the hostility score worsened by 0.16 (0.04-0.27), the self-esteem score worsened by 0.25 (0.12-0.38), and the pessimism score worsened by 0.17 (0.04-0.30) (all p < .01).

CONCLUSION

HL is related to numerous negative mood states beyond loneliness and depression. This includes worse anxiety, anger, hostility, self-esteem, and pessimism. Future studies should investigate whether treating HL improves negative emotional states.

Documentation of Peripheral Auditory Function in Studies of the Auditory P300 Response

Abstract. A critical review was conducted to examine whether the peripheral hearing status of participants with neurological and psychological disorders was documented in published clinical studies of the auditory P300 response. Literature searches were conducted with three databases: PubMed, PsycINFO, and Scopus. Studies of participants with seven neurological or psychological disorders were included in the study. Each disorder was coupled with the main search phrase in separate searches on each database. Of the total 102 papers which met the inclusion criteria, the majority (64%) did not describe the peripheral hearing sensitivity of participants. In this review with studies that included participants at risk for hearing impairment, particularly age-related hearing loss, only a single publication adequately described formal hearing evaluation. Peripheral hearing status is rarely defined in studies of the P300 response. The inclusion of participants with a hearing loss likely affects the validity of findings for these studies. We recommend formal hearing assessment prior to inclusion of participants in studies of the auditory P300 response. The findings of this study may increase the awareness among researchers outside the field of audiology of the effects of peripheral hearing loss on the auditory P300.

A precision medicine tool to understand who responds best to hearing aids in late-life depression

OBJECTIVES

Accumulating evidence suggests that hearing loss (HL) treatment may benefit depressive symptoms among older adults with Major Depressive Disorder (MDD), but the specific individual characteristics of those who stand to improve most are unknown.

METHODS

N = 37 patients ≥60 years with HL and MDD received either active or sham hearing aids in this 12-week double-blind randomized controlled trial. A combined moderator approach was utilized in the analysis in order to examine multiple different pretreatment individual characteristics to determine the specific qualities that predicted the best depressive symptom response to hearing aids. Pretreatment characteristics included: Hearing Handicap Inventory for the Elderly (HHIE-S), pure tone average (PTA), speech reception threshold (SRT), Short Physical Performance Battery (SPPB), cognition (Repeatable Battery for the Assessment of Neuropsychological Status).

RESULTS

The analysis revealed a combined moderator, predicting greater improvement with active versus sham hearing aids, that had a larger effect size than any individual moderator (combined effect size [ES] = 0.49 [95% CI: 0.36, 0.76]). Individuals with worse hearing-related disability (HHIE-S: individual ES = -0.16), speech recognition (SRT: individual ES = -0.14), physical performance (SPPB: individual ES = 0.41), and language functioning (individual ES = 0.19) but with relatively less severe audiometric thresholds (PTA: individual ES = 0.17) experienced greater depressive symptom improvement with active hearing aids.

CONCLUSIONS

Older adults with relatively worse HL-related, physical, and cognitive functioning may stand to benefit most from hearing aids. Given the large number of older adults experiencing HL and MDD, a non-invasive and scalable means of targeting those most likely to respond to interventions would be valuable.

Hearing Rehabilitative Treatment for Older Adults With Comorbid Hearing Loss and Depression: Effects on Depressive Symptoms and Executive Function

OBJECTIVES

Recent research has revealed important neural and psychiatric consequences of hearing loss (HL) in older adults. This pilot study examined the neural effects of HL and the impact of hearing aids on neuropsychiatric outcomes in major depressive disorder (MDD).

DESIGN

Twelve-week, double-blind, randomized controlled trial.

PARTICIPANTS/INTERVENTION

N = 25 (≥60 years) with MDD and moderate-profound HL were randomized to receive hearing aids (100% gain targets) or sham hearing aids (flat 30 dB HL) in addition to psychiatric treatment-as-usual.

MEASUREMENTS

Depressive symptoms (Hamilton Rating Scale for Depression [HRSD]), executive functioning (NIH Toolbox Flanker), integrity of auditory brain areas (structural MRI, diffusion tensor imaging).

RESULTS

At baseline, worse speech discrimination was associated with auditory cortical thinning (Left anterior transverse temporal gyrus: r = 0.755, p = 0.012) and lower integrity of the superior longitudinal fasciculus (FA: Left r = 0.772, p = 0.025, Right r = 0.782, p = 0.022). After 12-weeks, hearing aids were effective at improving hearing functioning (Hearing Handicap for the Elderly: active -12.47 versus sham -4.19, t = -2.64, df = 18, p = 0.016) and immediate memory (active +14.9 versus sham +5.7, t = 2.28, df = 16, p = 0.037). Moderate improvement was observed for hearing aids on executive functioning but did not reach statistical significance (Flanker: active +4.8 versus sham -2.4, t = 1.95, df = 15, p = 0.071). No significant effect on depression was found (HRSD: active -5.50 versus sham -7.32, t = 0.75, df = 19, p = 0.46).

CONCLUSIONS

HL can affect brain regions important for auditory and cognitive processing, and hearing remediation may have beneficial effects on executive functioning in MDD. Future studies may evaluate whether impairment in cognitive control consequent to HL may be an important risk mechanism for MDD.

Hearing Loss and Cognition: What We Know and Where We Need to Go

Although a causal association remains to be determined, epidemiologic evidence suggests an association between hearing loss and increased risk of dementia. If we determine the association is causal, opportunity for targeted intervention for hearing loss may play a fundamental role in dementia prevention. In this discussion, we summarize current research on the association between hearing loss and dementia and review potential casual mechanisms behind the association (e.g., sensory-deprivation hypothesis, information-degradation hypothesis, common cause). We emphasize key areas of research which might best inform our investigation of this potential casual association. These selected research priorities include examination of the causal mechanism, measurement of co-existing hearing loss and cognitive impairment and determination of any bias in testing, potential for managing hearing loss for prevention of dementia and cognitive decline, or the potential to reduce dementia-related symptoms through the management of hearing loss. Addressing these research gaps and how results are then translated for clinical use may prove paramount for dementia prevention, management, and overall health of older adults.

The Longitudinal Association of Subclinical Hearing Loss With Cognition in the Health, Aging and Body Composition Study

Objectives

To examine the longitudinal association between subclinical hearing loss (SCHL) and neurocognitive performance.

Design

Longitudinal analyses were conducted among 2,110 subjects who underwent audiometric testing in a US multi-centered epidemiologic cohort study. The primary exposure was better ear hearing (pure tone average). SCHL was defined as hearing ≤ 25 dB. The primary outcome was neurocognitive performance, measured by Digit Symbol Substitution Test (DSST), Modified Mini Mental State Examination (3MS), and CLOX1. Linear mixed models were performed to assess the longitudinal association between hearing and cognitive performance, adjusting for covariates. Models were fit among all individuals and among individuals with SCHL only.

Results

Among 2,110 participants, mean (SD) age was 73.5 (2.9) years; 52.3% were women. Mean (SD) better ear pure tone average was 30.0 (13.1) dB. Mean follow-up was 9.1 years (range 3–16). Among all participants, worse hearing was associated with significantly steeper cognitive decline measured by the DSST [0.054-point/year steeper decrease per 10 dB worse hearing, 95% confidence interval (CI): 0.026–0.082] and 3MS (0.044-point/year steeper decrease per 10 dB worse hearing, CI: 0.026–0.062), but not CLOX1. Among those with SCHL, worse hearing was associated with significantly steeper cognitive performance decline as measured by DSST (0.121-point/year steeper decrease per 10 dB worse hearing, CI: 0.013–0.228), but not CLOX1 or 3MS.

Conclusion

Among those with SCHL, worse hearing was associated with steeper cognitive performance declines over time as measured by DSST. The relationship between hearing loss and cognition may begin at earlier levels of hearing loss than previously recognized.

The Relationship Between Hearing and Mild Behavioral Impairment and the Influence of Sex: A Study of Older Adults Without Dementia from the COMPASS-ND Study

Background:

Hearing loss and mild behavioral impairment (MBI), both non-cognitive markers of dementia, can be early warning signs of incident cognitive decline.

Objective:

We investigated the relationship between these markers and reported the influence of sex, using non-dementia participants (n = 219; 107 females) from the Canadian Comprehensive Assessment of Neurodegeneration and Dementia (COMPASS-ND).

Methods:

Hearing was assessed with the 10-item Hearing Handicap for the Elderly–Screening (HHIE-S) questionnaire, a speech-in-noise test, screening audiometry, and hearing aid use. MBI symptoms were assessed using the Neuropsychiatric Inventory Questionnaire (NPI-Q). Multivariable linear regressions examined the association between hearing and MBI symptom severity and multiple logistic regressions examined the association between hearing and MBI domains.

Results:

HHIE-S score was significantly associated with greater global MBI symptom burden, and symptoms in the apathy and affective dysregulation domains. Objective measures of audiometric hearing loss and speech-in-noise testing as well as hearing aid use were not associated with global MBI symptom severity or the presence of MBI domain-specific symptoms. Males were older, had more audiometric and speech-in-noise hearing loss, higher rates of hearing-aid use, and showed more MBI symptoms than females, especially apathy.

Conclusion:

The HHIE-S, a subjective self-report measure that captures emotional and social aspects of hearing disability, was associated with informant-reported global MBI symptom burden, and more specifically the domains of affective dysregulation and apathy. These domains can be potential drivers of depression and social isolation. Hearing and behavior change can be assessed with non-invasive measures, adding value to a comprehensive dementia risk assessment.

Effect of cochlear implantation on cognitive decline and quality of life in younger and older adults with severe-to-profound hearing loss

Purpose

(a) To measure the change in cognition, the improvement of speech perception, and the subjective benefit in people under and over 60 years following cochlear implantation. (b) To assess the relationship between cognition, demographic, audiometric, and subjective outcomes in both age groups.

Methods

28 cochlear implant (CI) users were assigned to the < 60y group and 35 to the ≥ 60y group. Cognition was measured using the Repeatable Battery for the Assessment of Neuropsychological Status for Hearing impaired individuals (RBANS-H); subjective benefit was measured using the Nijmegen Cochlear Implant Questionnaire (NCIQ); the Glasgow Benefit Inventory (GBI); the Hearing Implant Sound Quality Index (HISQUI₁₉); Speech, Spatial and Qualities of Hearing Scale (SSQ₁₂); and the Hospital Anxiety and Depression Scale (HADS).

Results

Prior to surgery: the RBANS-H total score positively correlated with the domains “Advanced sound”, “Self-esteem”, and “Social functioning” of NCIQ, and negatively with HADS scores. 12 months post-implantation: the RBANS-H total score increased in the < 60y (p = 0.038) and in the ≥ 60y group (p < 0.001); speech perception and subjective outcomes also improved; RBANS-H total score positively correlated with “Self-esteem” domain in NCIQ. Age and the RBANS-H total score correlated negatively in the ≥ 60y group (p = 0.026).

Conclusions

After implantation, both age groups demonstrated improved cognition, speech perception and quality of life. Their depression scores decreased. Age was inversely associated with cognition.

Age-Related Disparities in the Treatment of Borderline/Mild Hearing Loss in the United States

To investigate disparities in hearing aid use across the life span for borderline/mild hearing loss, a cross-sectional epidemiologic study in the National Health and Nutrition Examination Survey was conducted. Multivariable logistic regressions controlling for hearing level analyzed the association between hearing aid use and age in borderline/mild hearing loss. Age was grouped into quartiles. Of 2470 subjects, 2.0% (n = 50) were <25 years old; 12.0% (n = 297), 25 to 49 years; 65.5% (n = 1618), 50 to 74 years; and 20.5% (n = 505), ≥75 years. When compared with the youngest quartile and while controlling for hearing level, those in the second quartile were 4.6 times less likely to use hearing aids (P < .01); those in the third were 4.2 times less likely (P < .01); and those in the fourth were 4.7 times less likely (P < .001). The dramatically lower hearing aid usage of all older age groups as compared with children/younger adults represents a large unaddressed age-related disparity in the treatment of borderline/mild hearing loss.

Hearing Impairment and Cognition in an Aging World

With the increasing number of older adults around the world, the overall number of dementia cases is expected to rise dramatically in the next 40 years. In 2020, nearly 6 million individuals in the USA were living with Alzheimer's disease, the most common type of dementia, with anticipated growth to nearly 14 million by year 2050. This increasing prevalence, coupled with high societal burden, makes prevention and intervention of dementia a medical and public health priority. As clinicians and researchers, we will continue to see more individuals with hearing loss with other comorbidities including dementia. Epidemiologic evidence suggests an association between hearing loss and increased risk of dementia, presenting opportunity for targeted intervention for hearing loss to play a fundamental role in dementia prevention. In this discussion, we summarize current research on the association between hearing loss and dementia and review potential casual mechanisms behind the association (e.g., sensory-deprivation hypothesis, information-degradation hypothesis, common cause). We emphasize key areas of research which might best inform our investigation of this potential casual association. These selected research priorities include examination of the causal mechanism, measurement of co-existing hearing loss and cognitive impairment, and potential of aural rehabilitation. Addressing these research gaps and how results are then translated for clinical use is paramount for dementia prevention and overall health of older adults.

Neural circuits and behavioral pathways linking hearing loss to affective dysregulation in older adults

Substantial evidence now links age-related hearing loss to incident major depressive disorder in older adults. However, research examining the neural circuits and behavioral mechanisms by which age-related hearing loss leads to depression is at an early phase. It is known that hearing loss has adverse structural and functional brain consequences, is associated with reduced social engagement and loneliness, and often results in tinnitus, which can independently affect cognitive control and emotion processing circuits. While pathways leading from these sequelae of hearing loss to affective dysregulation and depression are intuitive to hypothesize, few studies have yet been designed to provide conclusive evidence for specific pathophysiological mechanisms. Here we review the neurobiological and behavioral consequences of age-related hearing loss, present a model linking them to increased risk for major depressive disorder and suggest how future studies may facilitate the development of rationally designed therapeutic interventions for older adults with impaired hearing to reduce risk for depression and/or ameliorate depressive symptoms.