ABSTRACT
OBJECTIVES: The purpose of the study was to assess the risk factors assumed to be related to the high frequency hearing loss in the noise-exposed male workers. METHODS: 712 occupationally noise-exposed male workers were included in this cross sectional study. The subjects filled out a questionnaire on the history of noise exposure, hearing protection, otologic diseases, tobacco smoking, and were tested on height, weight, hematocrit, serum total cholesterol level, fasting plasma glucose level and arterial blood pressure level. Pure tone audiometry and otoscopy were conducted and the subjects were allocated into two groups according to whether they had 4000 Hi hearing loss or not. RESULTS: The multiple logistic regression analysis showed that military noise exposure, poor wearing status of the hearing protection devices, increased age, long noise exposure duration, mean arterial pressure less than 80mmHg, high fasting plasma sugar are the factors significantly related to high frequency hearing loss (P<0.05). On the contrary, there was no significant relationship between noise intensity, body mass index, serum total cholesterol level, smoking and high frequency hearing loss. Low hematocrit was shown to be a significant factor with a p-value less than 0.1. CONCLUSIONS: High frequency hearing loss in the noise-exposed male workers is related to military noise exposure, use of hearing protection devices, age, noise exposure length, fasting glucose level and mean arterial pressure, in this order. Appropriate use of the hearing protection devices has a great impact on the prevention of the noise-induced hearing loss.
