Hearing-impairment among workers in a surface gold mining company in Ghana.

A study to determine the impact of hazardous noise on workers was conducted in a surface gold mining company in Ghana. The procedure adopted included noise survey, case history, otoscopy and conventional pure-tone audiometry. Five main areas were surveyed for hazardous noise namely, Pit, Processing, Ana Laboratory, Bore-hole and Mess area. The results showed that all the above areas except the Mess area produced noise levels above 85 dBA. Again, a total of 252 workers were seen at the company, and out of this number 59(23%) had the classical noise-induced hearing loss (NIHL) at 4 KHz. In addition, NIHL increased as a function of age and duration of exposure. It is also noted that out of 81 workers with a preemployment history of noise exposure, 41(51%) had NIHL. NIHL also varied with regard to job location. 14(6%) of the workers had hearing loss greater than 25 dB at the speech frequencies. Thus, factors not under the control of the company may affect the hearing of an employee.