Prevalence and degree of noise-induced hearing loss in South African gold miners

Abstract

This study aimed to describe the prevalence of noise-induced hearing loss (NIHL) in a large group of gold miners (N=57 714). Noise exposure levels were used to categorise participants into different noise group categories and a control group. HFA346 and LFA512 (high and low frequency) averages were calculated from hearing thresholds and, where possible, analyses were adjusted for age. The study found that exposure to occupational noise, despite hearing conservation programmes, was signifi cantly associated with increased hearing thresholds. Results indicated that the noise-exposed groups had signifi cantly higher prevalence rates of HFA346 and LFA512 hearing loss than the control group. The largest difference in prevalence of HFA346 hearing loss was observed for ages 36-45 years. HFA346 hearing loss was also observed in the control group. HFA346 hearing loss prevalence was affected by age, which should be taken into account when determining or predicting the effect of noise on hearing.