Associations Between Traumatic Brain Injury and Severity of Tinnitus-Related Functional Impairment Among US Military Veterans: A National, Population-Based Study.

OBJECTIVE: To describe associations between a history of traumatic brain injury (TBI) and the severity of tinnitus-related functional impairment among a national, stratified random sample of veterans diagnosed with tinnitus by the Department of Veterans Affairs (VA) healthcare system. SETTING: A multimodal (mailed and internet) survey administered in 2018. Participants: VA healthcare-using veterans diagnosed with tinnitus; veterans with comorbid TBI diagnosis were oversampled. DESIGN: A population-based survey. MAIN MEASURES: TBI history was assessed using International Classification of Diseases (ICD) diagnosis codes in veterans' VA electronic health records. The severity of participants' overall tinnitus-related functional impairment was measured using the Tinnitus Functional Index. Population prevalence and 95% confidence intervals (CIs) were estimated using inverse probability weights accounting for sample stratification and survey nonresponse. Veterans' relative risk ratios of very severe or moderate/severe tinnitus-related functional impairment, versus none/mild impairment, were estimated by TBI history using bivariable and multivariable multinomial logistic regression. RESULTS: The population prevalence of TBI was 5.6% (95% CI: 4.8-6.4) among veterans diagnosed with tinnitus. Veterans with a TBI diagnosis, compared with those without a TBI diagnosis, had 3.6 times greater likelihood of rating their tinnitus-related impairment as very severe (95% CI: 2.1-6.3), and 1.5 times greater likelihood of rating their impairment as moderate/severe (95% CI: 1.0-2.4), versus none/mild. CONCLUSIONS: These findings suggest an important role of TBI in the severity of tinnitus-related functional impairment among veterans. This knowledge can help inform the integration of tinnitus management services into the care received by veterans with TBI.

The Impact of Tinnitus Severity on Work Functioning among U.S. Military Veterans with Tinnitus.

Tinnitus is highly prevalent among military Veterans. Severe tinnitus can be associated with negative impacts on daily life. Veterans with severe tinnitus may also have greater difficulties in functional roles, including work. However, few studies have explicitly explored this relationship. Traumatic brain injury (TBI), also prevalent among Veterans, is associated with tinnitus and can additionally impair work functioning. This quantitative investigation used a population-based survey to assess the relationship between tinnitus severity, measured using the Tinnitus Functional Index (TFI), and the impact of tinnitus on work, measured using a composite score from the Tinnitus History Questionnaire, among a stratified random sample of VA healthcare-using Veterans diagnosed with tinnitus, with and without comorbid TBI. Analyses were weighted to account for sampling design and Veteran non-response; multiple imputation was used to account for missing data. Results indicated that for every 1-point increase in TFI score, there was an average 8% increase in the odds of reporting a high level of impact on work functioning (OR: 1.08; 95% CI: 1.06, 1.11). Veterans with a comorbid TBI diagnosis, compared with those without, were more likely to have high tinnitus-related impact on work functioning (OR: 2.69, 95% CI: 1.85, 3.91), but the relationship between tinnitus severity and the impact of tinnitus on work functioning did not differ by TBI status. These data can help researchers and clinicians understand complex symptoms experienced by Veterans with tinnitus, with and without TBI, supporting the improved provision of clinical services to these patients.

History of Tinnitus Research at the VA National Center for Rehabilitative Auditory Research (NCRAR), 1997-2021: Studies and Key Findings.

The Veterans Affairs (VA) Rehabilitation Research & Development (RR&D) National Center for Rehabilitative Auditory Research (NCRAR) was first funded by the RR&D Service in 1997 and has been funded continuously since that time. The overall purpose of the NCRAR is to "improve the quality of life of Veterans and others with hearing and balance problems through clinical research, technology development, and education that leads to better patient care" ( www.ncrar.research.va.gov ). An important component of the research conducted at the NCRAR has been a focus on clinical and rehabilitative aspects of tinnitus. Multiple investigators have received grants to conduct tinnitus research and the present article provides an overview of this research from the NCRAR's inception through 2021.

Military and Nonmilitary TBI Associations with Hearing Loss and Self-Reported Hearing Difficulty among Active-Duty Service Members and Veterans.

OBJECTIVE: Identify associations between self-reported history of military and nonmilitary traumatic brain injury (TBI) on hearing loss and hearing difficulty from the Noise Outcomes in Servicemembers Epidemiology (NOISE) study. STUDY DESIGN: Cross-sectional. SETTING: Multi-institutional tertiary referral centers. PATIENTS: Four hundred seventy-three Active-Duty Service members (ADSM) and 502 veterans. EXPOSURE: Self-reported history of no TBI, military TBI only, nonmilitary TBI only, both military and nonmilitary TBI. MAIN OUTCOME MEASURES: Pure-tone hearing thresholds, Speech Recognition In Noise Test (SPRINT), Hearing Handicap Inventory for Adults (HHIA), and Speech, Spatial and Qualities of Hearing Scale (SSQ)-12. RESULTS: 25% (120/473) of ADSM and 41% (204/502) of veterans self-reported a TBI. Military TBI was associated with poorer hearing thresholds in all frequency ranges in veterans (adjusted mean difference, 1.8 dB; 95% confidence interval [CI], 0.5-3.0; 3.3, 0.8-5.8; 5.1; 1.7-8.5, respectively), and in the high frequency range in ADSM (mean difference, 3.2 dB; 95% CI, 0.1-6.3). Veterans with military TBI only and nonmilitary TBI only had lower odds of correctly identifying speech in noise than veterans with no TBI (odds ratio [OR], 0.78; 95% CI, 0.72-0.83; 0.90; 0.84-0.98). ADSM with a military TBI (OR, 5.7; 95% CI, 2.6-12.5) and veterans with any TBI history (OR, 2.5; 95% CI, 1.5-4.3; OR, 2.2; 95% CI, 1.3-3.8; OR, 4.5; 95% CI, 2.1-9.8) were more likely to report hearing difficulty on HHIA. SSQ-12 results corroborated HHIA findings. CONCLUSIONS: Military TBI was associated with poorer hearing thresholds in veterans and ADSM, and poorer SPRINT scores in veterans. Military TBI was associated with poorer self-perceived hearing ability in ADSM. All types of TBI were associated with poorer self-perceived hearing ability in veterans, although the strength of this association was greatest for military TBI.

Hearing Loss Prevalence, Years Lived With Disability, and Hearing Aid Use in the United States From 1990 to 2019: Findings From the Global Burden of Disease Study.

OBJECTIVES: This article describes key data sources and methods used to estimate hearing loss in the United States, in the Global Burden of Disease study. Then, trends in hearing loss are described for 2019, including temporal trends from 1990 to 2019, changing prevalence over age, severity patterns, and utilization of hearing aids. DESIGN: We utilized population-representative surveys from the United States to estimate hearing loss prevalence for the Global Burden of Disease study. A key input data source in modeled estimates are the National Health and Nutrition Examination Surveys (NHANES), years 1988 to 2010. We ran hierarchical severity-specific models to estimate hearing loss prevalence. We then scaled severity-specific models to sum to total hearing impairment prevalence, adjusted estimates for hearing aid coverage, and split estimates by etiology and tinnitus status. We computed years lived with disability (YLDs), which quantifies the amount of health loss associated with a condition depending on severity and creates a common metric to compare the burden of disparate diseases. This was done by multiplying the prevalence of severity-specific hearing loss by corresponding disability weights, with additional weighting for tinnitus comorbidity. RESULTS: An estimated 72.88 million (95% uncertainty interval (UI) 68.53 to 77.30) people in the United States had hearing loss in 2019, accounting for 22.2% (20.9 to 23.6) of the total population. Hearing loss was responsible for 2.24 million (1.56 to 3.11) YLDs (3.6% (2.8 to 4.7) of total US YLDs). Age-standardized prevalence was higher in males (17.7% [16.7 to 18.8]) compared with females (11.9%, [11.2 to 12.5]). While most cases of hearing loss were mild (64.3%, 95% UI 61.0 to 67.6), disability was concentrated in cases that were moderate or more severe. The all-age prevalence of hearing loss in the United States was 28.1% (25.7 to 30.8) higher in 2019 than in 1990, despite stable age-standardized prevalence. An estimated 9.7% (8.6 to 11.0) of individuals with mild to profound hearing loss utilized a hearing aid, while 32.5% (31.9 to 33.2) of individuals with hearing loss experienced tinnitus. Occupational noise exposure was responsible for 11.2% (10.2 to 12.4) of hearing loss YLDs. CONCLUSIONS: Results indicate large burden of hearing loss in the United States, with an estimated 1 in 5 people experiencing this condition. While many cases of hearing loss in the United States were mild, growing prevalence, low usage of hearing aids, and aging populations indicate the rising impact of this condition in future years and the increasing importance of domestic access to hearing healthcare services. Large-scale audiometric surveys such as NHANES are needed to regularly assess hearing loss burden and access to healthcare, improving our understanding of who is impacted by hearing loss and what groups are most amenable to intervention.

Prevalence of Hyperacusis Diagnosis in Veterans Who Use VA Healthcare.

OBJECTIVES: The primary objective was to estimate the prevalence of hyperacusis diagnosis in treatment-seeking Veterans, paying attention to when it is diagnosed in conjuncture with common comorbid conditions. DESIGN: This retrospective observational study used Veteran electronic health records from January 2015 to July 2021. Hyperacusis and comorbid conditions were identified using International Classification of Disease diagnostic codes. RESULTS: The prevalence of hyperacusis diagnosis was 0.06%. Veterans diagnosed with tinnitus, posttraumatic stress disorder, headache, or traumatic brain injury were between two and seven times more likely to have an International Classification of Disease code for hyperacusis. CONCLUSIONS: The estimated prevalence of hyperacusis diagnosis using electronic health records is grossly below what is reported in the literature. This is likely due to lack of standardized methods to diagnosis hyperacusis and when present with comorbid conditions, uncertainty when it should be coded as a secondary diagnosis. Future clinical and research efforts prioritizing hyperacusis are desperately needed.

Prevalence and Risk Factors of Self-reported Dizziness in Post-9/11 Service Members and Veterans.

INTRODUCTION: Dizziness is prevalent in the general population, but little is known about its prevalence in the U.S. military population. Dizziness is commonly associated with blast exposure and traumatic brain injury (TBI), but the potential independent contributions of blast and TBI have yet to be evaluated. This study's goal was to estimate the prevalence of dizziness among post-9/11 service members and Veterans and to examine independent and joint associations between military TBI history, blast exposure, and self-reported dizziness. MATERIALS AND METHODS: The study sample consisted of service members (n = 424) and recently separated (< ∼2.5 years) Veterans (n = 492) enrolled in the Noise Outcomes in Service members Epidemiology (NOISE) Study. We examined associations between self-reported history of probable TBI and blast exposure and recent dizziness using logistic regression. Models were stratified by service member versus Veteran status and adjusted to account for potentially confounding demographic and military characteristics. RESULTS: Overall, 22% of service members and 31% of Veterans self-reported dizziness. Compared to those with neither TBI nor blast exposure history, both service members and Veterans with TBI (with or without blast) were three to four times more likely to self-report dizziness. Those with blast exposure but no TBI history were not more likely to self-report dizziness. There was no evidence of an interaction effect between blast exposure and a history of TBI on the occurrence of dizziness. CONCLUSION: Self-reported dizziness was prevalent in this sample of service members and Veterans. Probable TBI history, with or without blast exposure, was associated with dizziness, but blast exposure without TBI history was not. This suggests that treatment guidelines for TBI-related dizziness may not need to be tailored to the injury mechanism. However, future efforts should be directed toward the understanding of the pathophysiology of TBI on self-reported dizziness, which is fundamental to the design of treatment strategies.

Descriptive Characterization of High-Frequency Distortion Product Otoacoustic Emission Source Components in Children.

PURPOSE: Distortion product otoacoustic emissions (DPOAEs) provide an objective assessment of cochlear function and are used for serial ototoxicity monitoring in pediatric cancer patients. DPOAEs are modeled as having distortion (near f2) and reflection (near 2f1-f2) component sources, and developmental changes are observed in these components' relative strengths in infants compared with adults. However, little is known about source component strengths in childhood or at extended high frequencies (EHFs; > 8 kHz). Thus, the purpose of this study was to describe the effects of age and stimulus frequency on DPOAE components in children. METHOD: DPOAEs were collected with varied frequency ratios (f2/f1 = 1.1-1.25) for a wide range of frequencies (2-16 kHz) in 39 younger (3-6 years) and 41 older (10-12 years) children with constant levels (L1/L2) of 65/50 dB SPL. A depth-compensated simulator sound pressure level method of calibration was employed. A time waveform representation of the results across various ratios was created to estimate peak pressures and latencies of each DPOAE component. RESULTS: Estimated peak pressures of DPOAE components revealed the greatest differences in DPOAE sources between children occurring at the highest frequencies tested, where the peak pressure of both components was largest for younger compared with older children. Latency differences between the children were only noted at higher frequencies for the distortion component. CONCLUSIONS: These results suggest that DPOAE levels decrease with age and reflection emissions are vulnerable to cochlear change. This work guides optimization of protocols for pediatric ototoxicity monitoring, whereby including EHF otoacoustic emissions is clearly warranted and choosing to isolate DPOAE sources may prove beneficial. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.23669214.

Tinnitus Screener: Short-Term Test-Retest Reliability.

PURPOSE: The Tinnitus Screener was introduced in 2015 as a four-item algorithmic instrument to assess the temporal characteristics of a person's reported tinnitus. The Tinnitus Screener was then revised as a six-item version to include a new temporal category and to capture tinnitus duration (acute < 6 months vs. chronic ≥ 6 months). When contrasted with audiologist assessment, the four-item Tinnitus Screener was determined to be highly valid, but the short-term reliability of either version remained unknown. The present analysis focused on determining the test-retest reliability of the six-item Tinnitus Screener. Additionally, we sought to determine whether reliability differed by respondent age, sex, military status, and hearing loss. METHOD: The Tinnitus Screener was administered to 190 military Service members and 250 military Veterans at two time points separated by 7-31 days. Our analysis focused on test-retest reliability of responses as measured by the kappa coefficient, overall and within subsamples. Percent agreement of tinnitus categorization (temporal categories) and classification (positive/negative) between the two time points was also evaluated. RESULTS: Constant or intermittent tinnitus was found in 31% of Service members and 53% of Veterans. Overall, kappa reliability coefficients were high, near .80, indicating substantial reliability. The majority (96%) of reliability coefficients for the Tinnitus Screener within subsamples were similarly high, ranging from .68 to .88. CONCLUSIONS: The updated version of the Tinnitus Screener is shown to be a reliable instrument. The Tinnitus Screener is recommended to inform clinical decision making by determining the temporal characteristics of tinnitus.

Associations between medical conditions and auditory dysfunction in US Veterans.

OBJECTIVE: To examine associations between non-otologic medical conditions and auditory dysfunction. DESIGN: Cross-sectional analysis of baseline data from the Noise Outcomes in Service members Epidemiology (NOISE) study. Logistic regression was used to estimate the association between medical conditions (0, 1, and 2 or more conditions) and auditory dysfunction (hearing loss pure tone average ≥20 dB HL and tinnitus), adjusting for key confounders including noise exposure. Secondarily, the association between specific medical conditions and auditory dysfunction was examined. All variables were self-reported. STUDY SAMPLE: United States military Veterans (n = 580) with mean age 34.1 years (standard deviation = 9.2), who were within approximately 2.5 years of separation from service. RESULTS: Compared to Veterans reporting no medical conditions, Veterans reporting two or more had increased odds on low-frequency hearing loss and on tinnitus but not on high or extended-high frequency hearing loss. Furthermore, specific conditions sleep disorder and arthritis were associated with auditory dysfunction. CONCLUSIONS: Non-otologic medical conditions were associated with low-frequency hearing loss and tinnitus in this sample of young Veterans. This suggests medical conditions may play a role in Veterans' hearing health. Whether management of medical conditions earlier in life reduces the risk of hearing loss and tinnitus requires further study.

The influence of tinnitus and hearing loss on the functional status of military Service members and Veterans.

OBJECTIVE: This study evaluated the influence of tinnitus and hearing loss on the functional status of military Service members and Veterans. DESIGN: Participants completed audiologic testing and self-report instruments to assess tinnitus, hearing, and general functioning. We conducted multiple linear regression analyses using cross-sectional data with functional status as the dependent variable. The primary independent variables were tinnitus and average low-, high-, and extended high-frequency hearing thresholds. Secondary independent variables were subjective tinnitus severity and hearing difficulties. Each of the independent variables was modelled separately for Service members and Veterans; covariates for each multivariable model were identified a priori and, depending on the association being modelled, included age, gender, blast-wave exposure, and history of military traumatic brain injury. STUDY SAMPLE: Data were analysed from 283 Service members and 390 Veterans. RESULTS: After controlling for potential confounders, presence of tinnitus, tinnitus severity, average low-frequency hearing thresholds, and subjective hearing difficulties were significantly associated with functional status in Service members and Veterans. CONCLUSIONS: These results suggest that tinnitus and poorer low-frequency hearing, and the perceived severity of tinnitus and hearing difficulties, may be associated with poorer functional status among Service members and Veterans.

Sex-Linked Biology and Gender-Related Research Is Essential to Advancing Hearing Health.

There is robust evidence that sex (biological) and gender (behavioral/social) differences influence hearing loss risk and outcomes. These differences are noted for animals and humans-in the occurrence of hearing loss, hearing loss progression, and response to interventions. Nevertheless, many studies have not reported or disaggregated data by sex or gender. This article describes the influence of sex-linked biology (specifically sex-linked hormones) and gender on hearing and hearing interventions, including the role of sex-linked biology and gender in modifying the association between risk factors and hearing loss, and the effects of hearing loss on quality of life and functioning. Most prevalence studies indicate that hearing loss begins earlier and is more common and severe among men than women. Intrinsic sex-linked biological differences in the auditory system may account, in part, for the predominance of hearing loss in males. Sex- and gender-related differences in the effects of noise exposure or cardiovascular disease on the auditory system may help explain some of these differences in the prevalence of hearing loss. Further still, differences in hearing aid use and uptake, and the effects of hearing loss on health may also vary by sex and gender. Recognizing that sex-linked biology and gender are key determinants of hearing health, the present review concludes by emphasizing the importance of a well-developed research platform that proactively measures and assesses sex- and gender-related differences in hearing, including in understudied populations. Such research focus is necessary to advance the field of hearing science and benefit all members of society.

Contralateral inhibition of distortion product otoacoustic emissions in young noise-exposed Veterans.

Although animal models show a clear link between noise exposure and damage to afferent cochlear synapses, the relationship between noise exposure and efferent function appears to be more complex. Animal studies indicate that high intensity noise exposure reduces efferent medial olivocochlear (MOC) reflex strength, whereas chronic moderate noise exposure is associated with a conditioning effect that enhances the MOC reflex. The MOC reflex is predicted to improve speech-in-noise perception and protects against noise-induced auditory damage by reducing cochlear gain. In humans, MOC reflex strength can be estimated by measuring contralateral inhibition of distortion product otoacoustic emissions (DPOAEs). The objective of this study was to determine the impact of military noise exposure on efferent auditory function by measuring DPOAE contralateral inhibition in young Veterans and non-Veterans with normal audiograms. Compared with non-Veteran controls, Veterans with high levels of reported noise exposure demonstrated a trend of reduced contralateral inhibition across a broad frequency range, suggesting efferent damage. Veterans with moderate noise exposure showed trends of reduced inhibition from 3 to 4 kHz but greater inhibition from 1 to 1.5 kHz, consistent with conditioning. These findings suggest that, in humans, the impact of noise exposure on the MOC reflex differs depending on the noise intensity and duration.

The Impacts of Noise Exposure on the Middle Ear Muscle Reflex in a Veteran Population.

PURPOSE: Human studies of noise-induced cochlear synaptopathy using physiological indicators identified in animal models (auditory brainstem response [ABR] Wave I amplitude, envelope following response [EFR], and middle ear muscle reflex [MEMR]) have yielded mixed findings. Differences in the population studied may have contributed to the differing results. For example, due to differences in the intensity level of the noise exposure, noise-induced synaptopathy may be easier to detect in a military Veteran population than in populations with recreational noise exposure. We previously demonstrated a reduction in ABR Wave I amplitude and EFR magnitude for young Veterans with normal audiograms reporting high levels of noise exposure compared to non-Veteran controls. In this article, we expand on the previous analysis in the same population to determine if MEMR magnitude is similarly reduced. METHOD: Contralateral MEMR growth functions were obtained in 92 young Veterans and non-Veterans with normal audiograms, and the relationship between noise exposure history and MEMR magnitude was assessed. Associations between MEMR magnitude and distortion product otoacoustic emission, EFR, and ABR measurements collected in the same sample were also evaluated. RESULTS: The results of the statistical analysis, although not conventionally statistically significant, suggest a reduction in mean MEMR magnitude for Veterans reporting high noise exposure compared with non-Veteran controls. In addition, the MEMR appears relatively insensitive to subclinical outer hair cell dysfunction, as measured by distortion product otoacoustic emissions, and is not well correlated with ABR and EFR measurements. CONCLUSIONS: When combined with our previous ABR and EFR findings in the same population, these results suggest that noise-induced synaptopathy occurs in humans. In addition, the findings indicate that the MEMR may be a good candidate for noninvasive diagnosis of cochlear synaptopathy/deafferentation and that the MEMR may reflect the integrity of different neural populations than the ABR and EFR. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.18665645.

Blast Exposure and Self-Reported Hearing Difficulty in Service Members and Veterans Who Have Normal Pure-Tone Hearing Sensitivity: The Mediating Role of Posttraumatic Stress Disorder.

Purpose Evidence suggests that military blast exposure may lead to self-reported hearing difficulties despite audiometrically normal hearing. Research identifying potential mechanisms of this association remains limited. The purpose of this article is to evaluate the associations between blast, posttraumatic stress disorder (PTSD), and self-reported hearing difficulty, and to examine PTSD as a possible mediator of the association between blast exposure and hearing difficulty. Method We used baseline data from the Noise Outcomes in Service members Epidemiology (NOISE) study (n = 477). Participants in this study undergo a comprehensive hearing, and tinnitus if applicable, evaluation and complete a large number of surveys. Pertinent data extracted from these surveys included information on participant's demographics, military service history, including exposure to blast, and health conditions such as symptoms of PTSD. Using regression models and following a formal causal mediation framework, we estimated total associations, natural direct and indirect associations, and percent mediated. Results We found that individuals with blast exposure had higher prevalence of both probable PTSD and self-reported hearing difficulty than individuals who were not blast exposed. Compared with participants without blast exposure, those with blast exposure had twice the prevalence of self-reported hearing difficulty, with 41% of the association mediated through probable PTSD. Conclusion As PTSD is a possible mediator of the association between blast exposure and hearing difficulty, Service members and Veterans with normal pure-tone hearing sensitivity who report hearing difficulties and a history of blast exposure may benefit from evaluation for PTSD symptoms. Supplemental Material https://doi.org/10.23641/asha.16674247.

Occupational Noise Exposure and Longitudinal Hearing Changes in Post-9/11 US Military Personnel During an Initial Period of Military Service.

OBJECTIVES: Auditory impairments, particularly those resulting from hazardous occupational noise exposures, are pressing concerns for the US Departments of Defense (DoD) and Veterans Affairs (VA). However, to date, no studies have estimated the rate of hearing threshold change that occurs during service or how changes may vary by military occupation. Hearing threshold changes during military service have historically been reported as the proportion of Service members demonstrating a significant threshold shift. This approach does not capture the rate of the hearing threshold change or the specific audiometric frequencies impacted. Determining the rate of hearing threshold change, and factors that affect the rate of change, is important to elucidate the impact of military service on hearing and to guide prevention strategies and subsequent hearing health care. Our primary objective was to estimate the annual rate of hearing threshold change during military service as a consequence of military occupational noise exposure ranking. DESIGN: We linked audiometric data, collected from military personnel as part of a DoD hearing conservation program, to data describing demographic and military-service characteristics obtained from individuals enrolled in the Noise Outcomes In Service members Epidemiology Study. The analytic cohort included Veterans who enlisted in military service after September 2001 (n = 246). We examined the longitudinal association between military occupations categorized as having a low, moderate, or high noise exposure ranking and pure-tone hearing thresholds (500 to 6000 Hz) using a hierarchical linear model. The average annual rate of hearing threshold change and their 95% confidence intervals were estimated by service branch, military occupational noise exposure ranking, and audiometric test frequency. RESULTS: On average, hearing threshold change ranged between -0.5 and 1.1 dB/year and changes over time varied by service branch, audiometric test frequency, and military occupation noise ranking. Generally, higher test frequencies (3000 to 6000 Hz) and military occupations with moderate or high noise exposure rankings had the greatest average annual rates of hearing threshold change; however, no dose-response relationship was observed. Among Marine Corps personnel, those exposed to occupations with high noise rankings demonstrated the greatest average annual rate of change (1.1 dB/year at 6000 Hz). Army personnel exposed to occupations with moderate noise rankings demonstrated the greatest average annual rate of change (0.6 dB/year at 6000 Hz). CONCLUSIONS: This study (1) demonstrates the unique use of DoD hearing conservation program data, (2) is the first analysis of hearing threshold changes over time using such data, and (3) adds to the limited literature on longitudinal changes in hearing. The difference in hearing threshold changes across military branches is likely indicative of their varying noise exposures, hearing protection device use and enforcement, and surveillance practices. Results suggest Marine Corps and Army personnel are at risk for hearing threshold changes and that, among Army personnel, this is most pronounced among those exposed to moderate levels of occupational noise exposure. Estimates of the rate of hearing threshold change by frequency and factors that impact hearing are useful to inform the DoD's efforts to protect the hearing of their Service members and to the Veterans Affairs's efforts to identify and rehabilitate those most likely to experience hearing threshold change.

Noise Outcomes in Servicemembers Epidemiology (NOISE) Study: Design, Methods, and Baseline Results.

OBJECTIVES: Military Service members and Veterans commonly report hearing loss and tinnitus, both of which can result in significant disability. During military service, Service members are exposed to many different types of loud noise, which is strongly associated with hearing loss and tinnitus. Other military-related exposures, such as chemicals and traumatic brain injury (TBI), are also linked with auditory problems. The purpose of the "Noise Outcomes in Servicemembers Epidemiology" (NOISE) study is to gather information from Active-Duty Service members and recently separated Veterans about their military and nonmilitary noise exposures, other relevant military and nonmilitary exposures, and potential outcomes of these exposures including tinnitus, hearing loss, and other hearing-related health concerns. DESIGN: The NOISE study assesses lifetime noise exposures, chemical and blast exposures, TBI, physical and psychiatric comorbidities, and other military and nonmilitary exposures and outcomes that can affect auditory function. Participants undergo comprehensive in-person audiologic examinations; those who experience tinnitus undergo a complete tinnitus assessment. Exposures and select outcomes are reassessed annually by mail, and the comprehensive in-person assessment is completed every 5 years. This report presents descriptive, baseline data obtained from the first 690 participants enrolled between 2014 and 2018. RESULTS: Some notable findings from this analysis include: (1) the prevalence of hearing loss in the sample was 8% for low frequencies (0.25 to 2 kHz), 20% for high frequencies (3 to 8 kHz), and 39% for extended high frequencies (9 to 16 kHz); (2) the prevalence of tinnitus was 53%; (3) the prevalence of both hearing loss and tinnitus was higher among those with higher age, more years of military service, greater degree of noise exposure, and exposures to blasts and/or TBI in the military; and (4) tinnitus was most prevalent among participants who serve/served in the Army relative to the other military branches. CONCLUSIONS: The NOISE study is acquiring comprehensive data on military-related auditory dysfunction. It is the first of its kind to enroll active Service members and recently separated Veterans into a longitudinal study to examine the etiology and outcomes of tinnitus and hearing loss in this population. Although these data do not necessarily represent the entire military and Veteran populations, ongoing enrollment is focused on increasing generalizability and will also provide the statistical power to conduct multivariable analyses. This will allow us to examine longitudinal associations of interest while controlling for potential confounders and other possible sources of error. These data will provide critical knowledge to refine future military hearing conservation efforts and inform efforts to develop future treatments.

Development and Initial Validation of the Lifetime Exposure to Noise and Solvents Questionnaire in U.S. Service Members and Veterans.

Purpose A need exists to investigate the short- and long-term impact of noise exposures during and following military service on auditory health. Currently available questionnaires are limited in their ability to meet this need because of (a) inability to evaluate noise exposures beyond a limited time frame, (b) lack of consensus on scoring, (c) inability to assess impulse exposures (e.g., firearm use), (d) lack of a single questionnaire that assesses both military and nonmilitary exposures, and (e) lack of validity and reliability data. To address these limitations, the Lifetime Exposure to Noise and Solvents Questionnaire (LENS-Q) was developed. The purpose of this report is to describe the development and initial validation of the LENS-Q as a measure of self-reported noise exposure. Method Six hundred ninety participants, consisting of current Service members and recently military-separated (within about 2.5 years) Veterans, completed the LENS-Q, additional study questionnaires, and comprehensive audiometric testing. Noise exposure scores were computed from LENS-Q responses using a simple scoring algorithm that distinguishes between different cumulative levels of exposure and allows for the inclusion of both continuous and impulse noise exposures. Results The LENS-Q demonstrates good construct validity as evidenced by measures of hearing loss, tinnitus, and subjective hearing difficulties all increasing with an increase in noise exposure scores. A logistic regression, adjusting for age and sex, revealed that participants in the highest exposure group were 2.4-3.9 times more likely to experience hearing loss, 2.7-2.8 times more likely to experience tinnitus, and 3.0-3.7 times more likely to report hearing difficulties compared with individuals in the lowest exposure group. Conclusions The LENS-Q captures noise exposure over an individual's lifetime and provides an alternative scoring metric capable of representing exposure to both continuous and impulse noise. Findings suggest that the LENS-Q is a valuable tool for capturing and measuring both military and nonmilitary noise exposure. Supplemental Material https://doi.org/10.23641/asha.14582937.

Mental Health Symptoms Among Veteran VA Users by Tinnitus Severity:A Population-based Survey.

INTRODUCTION: Tinnitus is prevalent among Service members and Veterans and is often comorbid with mental health disorders. Associations between the severity of individuals' tinnitus and mental health symptoms are not well described. MATERIALS AND METHODS: We conducted a population-based survey of a stratified random sample of 1,800 Veterans diagnosed with tinnitus. We used the Tinnitus Functional Index to measure tinnitus severity and the Primary Care-Posttraumatic Stress Disorder (PTSD) screen and the Hospital Anxiety and Depression Scale to assess PTSD, depression, and anxiety. Descriptive statistics and bivariable and multivariable regression models were used to estimate associations between Veterans' tinnitus severity and mental health symptoms. Inverse probability weights were used to account for sample stratification and survey non-response. Multivariable odds ratios (ORs) and 95% confidence intervals (CIs) controlled for Veterans' demographics, military history, and health diagnoses. RESULTS: A total of 891 Veterans completed surveys (adjusted response rate = 53%). Large proportions rated their tinnitus as severe (29.4%; 95% CI: 27.2-31.6) or very severe (18.7%; 95% CI: 16.8-20.5). In multivariable regression models, and compared with Veterans with none/mild tinnitus, the likelihood of screening positive for PTSD was increased for those who reported moderate (OR = 4.0; 95% CI: 1.6-10.3), severe (OR = 7.5; 95% CI: 3.1-18.5), or very severe (OR = 17.5; 95% CI: 4.4-70.0) tinnitus. Similarly, Veterans' likelihood of positive depression screens were elevated for those with moderate (OR = 2.6; 95% CI: 1.1-5.9), severe (OR = 3.0; 95% CI: 1.4-6.5), or very severe (OR = 15.5; 95% CI: 4.3-55.5) tinnitus, as was the likelihood of positive anxiety screens for those with severe (OR = 2.6; 95% CI: 1.1-6.3) or very severe (OR = 13.4; 95% CI: 4.0-44.3) tinnitus. CONCLUSIONS: Mental health symptoms are strongly associated with Veterans' tinnitus severity. A better understanding of the interplay between these conditions may help improve the provision of interdisciplinary (Audiology and Mental Health) care for Service members and Veterans.