One-day measurement to assess the auditory risks encountered by noise-exposed workers.

ABSTRACT

UNLABELLED Noise is one of the most pervasive hazards in the workplace. Despite regulations and preventive measures, noise-induced hearing loss is common. The current reference test is pure-tone air-conduction audiometry (PTA), but this test cannot be used to detect early hearing loss. OBJECTIVE: In this study, we assess one-day auditory fatigue using both PTA and efferent reflexes (ER) measured using DPOAEs associated with contralateral acoustic stimulation (CAS DPOAEs). DESIGN: The noise exposure history, PTA, and ER detection were performed in seven different companies where the L(EX,8h) was 85 dB(A). Hearing was tested before and at the end of the working day. STUDY SAMPLE Forty-six volunteers were selected to carry out this study. RESULTS: After a single working day, a greater impact of noise was measured using ER thresholds than PTA or DPOAEs. ER measurements are objective, easy to perform, and do not require a sound-attenuated booth. CONCLUSION: Screening workers by periodically measuring ER thresholds using CAS DPOAEs helps detect early changes in hearing status, before the onset of noise-induced hearing loss. These tests can be readily applied as part of a hearing conservation program.