Distribution of Hearing Thresholds and Hearing Loss among Noise-exposed Workers

Kim, Kyoo Sang

ORIGINAL ARTICLE

Commun Sci Disord. 2006;11(2): 106-121.

Kyoo Sang Kim^`

김규상(Kyoo Sang Kim)

ABSTRACT

This study was carried out to evaluate the hearing threshold levels and hearing impairment of noise-exposed workers. We obtained health examination data of noise-exposed workers from 70 special periodic health examination agencies. The data consisted of special periodic health examination results and audiograms that had been performed in examinations during the first half of 2003. We analyzed the hearing-threshold levels and relating factors of 10,823(male: female=9,464:1,359) noise-exposed workers at 403 workplaces. Sex, age, and duration of noise exposure were significantly related to the prevalence of screening above the hearing threshold levels in the first audiometric examination. The prevalence of secondary audiometric examinees among the male workers who had more than 30dBHL of pure tone average(PTA) or 50dBHL at 4000Hz was 31.0%. Among the secondary audiometric examinees, 57.6% was above 50dBHL of 4000Hz, 12.8% was above 30dBHL of PTA, and 8.7% was classified as having noise-induced hearing loss in the right ear of the male workers. Fifteen percent of the secondary audiometric examinees in the male workers suffered from a hearing loss above the mild level as judged by the ISO standard.