Influence of occupational noise on hearing: systematic review of foreign literature

The article is aimed to systematically review evidence-based data published in foreign literature on influence of level and characteristics of occupational noise on hearing loss. Search of the literature was based on key words "occupational noise exposure, permissible exposure limit, dose-response relationship, acceptable noise level, noise-induced hearing loss" The authors studied 349 publications, 7 out of which were included into the present systematic review. Findings are that developed countries demonstrate a tendency to decreased prevalence of hearing loss among workers exposed to noise. Occupational groups with increased risk include workers of mining, machinery, light industries and agriculture. Lower occupational risk or no risk of hearing loss is seen in education, transport workers, musicians and other groups. Occupational noise level of 80 dB is a theoretically minimal exposure level resulting in no increase in hearing loss risk. Following normal noise level at 85 dB could decrease prevalence of hearing loss due to noise.