Correlation of Industrial Noise Exposures with Audiometric Findings

A noise exposure profile system was developed following study of noise exposures and hearing losses among Dow employees. Four categories of severity were established ranging from quiet job (profiled “A”) to extremely noisy jobs (profiled “D”). The possible effects and interactions of noise exposure, age, time on the job, previous noise exposure, ear pathology, and the use of ear protection were studied. There was evidence that men working in jobs profiled “A” and “B” showed more hearing loss than was expected for normal ageing. Men in jobs profiled “C” and “D” showed hearing losses greater than those expected from ageing.