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.