Comprehensive Characterization of Hearing Loss and Tinnitus in Military-Affiliated and Non-Military-Affiliated Individuals.

PURPOSE: Military-affiliated individuals (MIs) are at a higher risk of developing hearing loss and tinnitus. While these disorders are well-studied in MIs, their impact relative to non-military-affiliated individuals (non-MIs) remains understudied. Our study compared hearing, speech-in-noise (SIN) perception, and tinnitus characteristics between MIs and non-MIs. METHOD: MIs (n = 84) and non-MIs (n = 193) underwent hearing threshold assessment and Quick Speech-in-Noise Test. Participants with tinnitus completed psychoacoustic tinnitus matching, numeric rating scale (NRS) for loudness and annoyance, and Tinnitus Functional Index. Comorbid conditions such as anxiety, depression, and hyperacusis were assessed. We used a linear mixed-effects model to compare hearing thresholds and SIN scores between MIs and non-MIs. A multivariate analysis of variance compared tinnitus characteristics between MIs and non-MIs, and a stepwise regression was performed to identify predictors of tinnitus severity. RESULTS: MIs exhibited better hearing sensitivity than non-MIs; however, their SIN scores were similar. MIs matched their tinnitus loudness to a lower intensity than non-MIs, but their loudness ratings (NRS) were comparable. MIs reported greater tinnitus annoyance and severity on the relaxation subscale, indicating increased difficulty engaging in restful activities. Tinnitus severity was influenced by hyperacusis and depression in both MIs and non-MIs; however, hearing loss uniquely contributed to severity in MIs. CONCLUSIONS: Our findings suggest that while MIs may exhibit better or comparable listening abilities, they were significantly more affected by tinnitus than non-MIs. Furthermore, our study highlights the importance of assessing tinnitus-related distress across multiple dimensions, facilitating customization of management strategies for both MIs and non-MIs.

Replicability of Neural and Behavioral Measures of Tinnitus Handicap in Civilian and Military Populations: Preliminary Results.

Purpose In the past decade, resting-state functional connectivity, acquired using functional magnetic resonance imaging (fMRI), has emerged as a popular measure of tinnitus, especially as related to self-reported handicap or psychological reaction. The goal of this study was to assess replicability of neural correlates of tinnitus, namely, resting-state functional connectivity, in the same individuals acquired over 2 sessions. Method Data were collected at 2 different sites (University of Illinois at Urbana-Champaign and Joint Base San Antonio Wilford Hall Ambulatory Surgical Center) using similar 3T magnets and similar data acquisition paradigms. Thirty-six patients (all civilians) were scanned using resting-state fMRI at the University of Illinois at Urbana-Champaign. Ten patients, active-duty Service members and Veterans, were scanned at the Wilford Hall Ambulatory Surgical Center and the Department of Defense Hearing Center of Excellence. Each participant was scanned twice, a week apart, using identical protocols of 10 min resting-state fMRI. Results Tinnitus handicap scores using the Tinnitus Functional Index and the Tinnitus Primary Function Questionnaire ranged between no or mild handicap to moderately severe handicap but did not significantly differ between visits. We examined the default mode, dorsal attention, and auditory resting-state networks and found that the strength of the within-network functional connections across visit was similar for the attention and default mode networks but not for the auditory network. In addition, the functional connection between the attention network and precuneus, a region of the default mode network, was also replicable across visits. Conclusions Our results show that resting-state fMRI measures are replicable and reliable in patients with a subjective condition, although some networks and functional connections may be more stable than others. This paves the way for using resting-state fMRI to measure the efficacy of tinnitus interventions and as a tool to help propose better management options.