Tinnitus and occupational noise exposure among informal generator technicians in Nigeria: A pilot cohort study

Abstract

Occupational noise exposure is a major cause of auditory dysfunction worldwide, and generator technicians in Nigeria represent a vulnerable informal workforce with prolonged exposure to high decibel noise. We conducted a population‑based, cross‑sectional cohort study of 73 generator technicians (age range 14-57 years, mean 34.9 ± 10.2 years). Subjective, non‑pulsatile tinnitus was assessed via a structured questionnaire, audiometric thresholds were measured using pure tone audiometry (PTA), and cochlear function was evaluated with distortion product otoacoustic emissions (DPOAEs). Logistic regression was used to identify independent predictors of tinnitus. Overall tinnitus prevalence was 45.2%, increasing across age groups from 33.3% in participants aged 14-24 years to 60% in those aged ≥55 years. Cross‑tabulation revealed tinnitus was most common among participants with normal PTA but failed OAE (100%). Logistic regression identified ≥10 years of occupational noise exposure (adjusted odds ratio [aOR] = 4.44) and OAE failure (aOR = 10.1) as independent predictors. Tinnitus was highly prevalent among this cohort of generator technicians and strongly associated with prolonged exposure and OAE failure. These findings underscore the complementary diagnostic role of OAE testing and highlight the urgent need for workplace hearing conservation strategies in informal sectors.