Abstract
There are significant individual differences in age-related changes in the hearing acuity. Theses individual differences are caused by genotypes as the internal factor, and various environmental and lifestyle factors as the external factors. It would be important to clarify these factors to minimize the development of hearing disturbances in the elderly. We confirmed the age-related changes in the hearing acuity among the 120, 000 men and women followed up for 18 years in Nagoya city. We also analyzed the factors that might influence individual differences in the hearing acuity based on detailed 10-year longitudinal data in 2, 400 community-living men and women. Age-related hearing disturbance was more prominent for high-pitched sounds than for low-pitched sounds, and disturbances in the hearing acuity were more significant in men than in women. Hearing acuity decreased in any generation both the sexes? during the 18-year follow-up from 1989. There were significant genetic influences in the age-related hearing disturbance. Presence of underlying chronic diseases such as diabetes, ischemic heart disease and renal diseases was also related to the hearing acuity. Significant association of the hearing acuity was also found with the presence of arteriosclerosis as determined by carotid artery ultrasonic tomography and examination of the ocular fundus. As for lifestyle factors, the effects of noise exposure and smoking were found to be significant in the age-related changes in hearing acuity.
