Occupational noise exposure and its effects on hearing threshold shifts and otolithic vestibular functions in male workers.

OBJECTIVE

Occupational noise exposure is associated with hearing loss, yet its impact on vestibular function is often underrecognized. This study aimed to investigate the manifestations and risk factors of noise-induced hearing threshold shifts and vestibular dysfunction among male workers exposed to occupational noise.

METHODS

Eighty-three male workers were recruited, and each completed a noise exposure questionnaire, audiometric examinations, and vestibular evoked myogenic potentials (VEMPs) testing. Participants were categorized into a noise exposure group (NE, n = 54) and a control group (CR, n = 29).

RESULTS

The NE group had significantly higher annual noise exposure levels [t(80.35) = 20.71, p < 0.001] and a higher prevalence of vestibular dysfunction than the CR group (Chi-square test, p < 0.01). The overall odds ratio for abnormal VEMPs in the NE group was 4.46 times greater than that of the CR group (95% CI [1.48, 13.41]). The potential factors contributing to noise-induced hearing threshold shift (NITS) in the NE group included age, years of service, annual noise exposure level, and the frequency of use of hearing protection devices (HPDs). However, HPD use was not associated with abnormal VEMP results.

CONCLUSIONS

This study showed that a substantial proportion of workers exposed to occupational noise exhibited NITS and signs of vestibular dysfunction. Monitoring occupational and daily noise exposure, emphasizing full-shift use of HPDs, and considering the impact of prolonged exposure on both auditory and vestibular systems are recommended.