Feasibility of a daily noise monitoring intervention for prevention of noise-induced hearing loss

BACKGROUND: Despite the existence of hearing conservation programmes complying with regulatory standards, noise-induced hearing loss (NIHL) remains one of the most prevalent occupational diseases. Compulsory daily monitoring of noise exposure has been associated with decreased NIHL risk. We report on the experience of a voluntary daily noise monitoring intervention among noise-exposed workers. METHODS: Workers at three locations of a metals manufacturing company voluntarily used an in-ear noise monitoring device that could record and download, on a daily basis, the noise exposure inside of their hearing protection. We compared the hearing loss rates (in decibels hearing level/year) in these volunteers to controls from the same company matched for job title, age, gender, race, plant location, and baseline hearing level. RESULTS: Over the follow-up period, 110 volunteers for whom controls could be identified monitored daily noise exposures an average of 150 times per year. Noise exposures inside of hearing protection were lower than ambient noise levels estimated from company records. While there was no significant difference in hearing loss rates between volunteers and controls, volunteers downloading exposures 150 times per year or had less hearing loss than those who downloaded less frequently. CONCLUSION: These results indicate that voluntary daily noise exposure monitoring by workers is feasible and that greater frequency of downloading is associated with less hearing loss. If further development of noise monitoring technology can improve usability and address barriers to daily use, regular self-monitoring of noise exposure could improve the effectiveness of hearing conservation programmes. TRIAL REGISTRATION NUMBER: NCT01714375.