Industrial Noise-Induced Hearing Loss in Hong Kong—a Comparative Study

The relationship between noise exposure and hearing loss was investigated in five groups of industrial workers in Hong Kong. Audiometric examinations were made on textile weavers, textile spinners, metal workers, aircraft maintenance crews and workers in a bottling factory. Noise surveys were conducted in each of the work environments. Audiometric examinations were also made on a control group consisting of workers in “non-noisy” occupations. The results were compared with data obtained from similar studies made in Western countries. In general, the results were similar and no evidence was found for any ethnic differences between Western groups and Cantonese Chinese either in general hearing levels or in response to prolonged exposure to industrial noise. Measured hearing loss was plotted against noise immission levels for four groups of workers and compared with median and quartile values predicted by ROBINSON and SHIPTON (1977). The agreement between the predicted curves and observed data was reasonably good for spinning workers and workers in the weaving and bottling industries, but hearing loss of workers in the metal-work industry tended to be greater than that predicted. These results are discussed in terms of the impulsive characteristics of the noise.