Early Auditory and Psychological Shifts in Newly Enlisted Republic of Korea Air Force Soldiers Exposed to Aircraft Noise: A Pilot Prospective Study

INTRODUCTION: Aircraft noise is an occupational and environmental stressor associated with auditory injury and adverse mental health outcomes, but prospective evidence in newly enlisted personnel remains limited. This pilot study examined early changes in hearing thresholds and psychological well-being among Republic of Korea Air Force soldiers. METHODS: Newly enlisted soldiers were enrolled at baseline ( n = 96); 52 completed 8-month follow-up. Air-conduction thresholds were measured at 250 to 8000 Hz. Psychological and sleep outcomes were assessed using the Patient Health Questionnaire-9 (PHQ-9), Beck Depression Inventory (BDI), Center for Epidemiologic Studies Depression Scale-Revised (CESD-R), Beck Anxiety Inventory (BAI), Pittsburgh Sleep Quality Index, and Insomnia Severity Index. Regression models adjusted for noise exposure and shift work evaluated associations between threshold shifts and psychological changes. RESULTS: Subclinical threshold shifts of 2 to 3 dB occurred at 4000 Hz in the right ear [False Discovery Rate-adjusted P -values ( PFDR ) = 0.007] and left ear ( PFDR = 0.047), and at 250 Hz in the right ear ( PFDR = 0.038). PHQ-9, CESD-R, and BAI scores increased over follow-up (all Praw < 0.05), although these changes were not significant after FDR adjustment (all PFDR > 0.05). No incident tinnitus was reported. In adjusted models, 4000 Hz threshold shifts showed borderline associations with increased BDI ( β = 0.350, PFDR = 0.057) and CESD-R scores ( β = 0.384, PFDR = 0.057). CONCLUSION: Short-term aircraft noise exposure was associated with early subclinical auditory shifts and numerical worsening of psychological measures. The 4000 Hz shift may represent a preliminary marker of depressive symptom emergence, supporting further investigation of sensory-psychological interactions in high-noise military environments.