Int J Audiol. 2018 Feb;57(sup1):S3-S11. doi: 10.1080/14992027.2017.1410237. Epub 2017 Dec 7.
OBJECTIVE: This study characterised overall and specific costs associated with hearing conservation programmes (HCPs) at US metal manufacturing sites, and examined the association between these costs and several noise-induced hearing loss (NIHL) outcomes.
DESIGN: We interviewed personnel and reviewed records at participating facilities. We also measured noise for comparison to the ten-year average of measurements made by each facility. NIHL outcomes assessed included rates of standard threshold shifts (STS) and high-frequency hearing loss, as well as prevalence of hearing impairment, for each participating facility. We used linear regression to identify per-person HCP costs that best predicted the NIHL outcomes.
STUDY SAMPLE: We evaluated 14 US metal manufacturing facilities operated by a single company.
RESULTS: Annual HCP costs ranged from roughly $67,000 to $397,000 (average $308 ± 80 per worker). Our full-shift noise measurements (mean 83.1 dBA) showed good agreement with the facilities’ measurements (mean 82.6 dBA). Hearing impairment prevalence was about 15% overall. Higher expenditures for training and hearing protector fit-testing were significantly associated with reduced STS prevalence. Higher training expenditures were also related to lower hearing impairment prevalence and high-frequency hearing loss rates.
CONCLUSIONS: HCP costs were substantial and variable. Increased workplace spending on training and fit-testing may help minimise NIHL.