A longitudinal study of hearing impairment in male subjects--an 8-year follow-up

As part of a longitudinal study, 135 male subjects with a median age of 65 years (range 57-77 years) were re-examined 3 and 8 years after the first examination. A significant deterioration in the hearing thresholds at 1 kHz to 8 kHz was demonstrated across an 8-year period covering a change in the median age from 57-65 years. The rate of change was most pronounced during the period from 60-65 years of age. The median hearing thresholds as well as the 25 and 75 percentiles are worse in the present study compared with a sex and age matched non-noise-exposed reference group (Spoor and Passchier-Vermeer, 1969 International Audiology, 8, 328 336) and a screened otologically normal reference group (ISO, 7029). When compared with an age and sex matched unscreened population (Robinson, 1988 British Journal of Audiology, 22, 5-20) the median hearing thresholds are almost identical. The prevalence of noise-induced hearing loss is 30% and the hearing ability in noise-exposed subjects is significantly poorer when compared to the total sample. In addition the hearing thresholds in the high-frequency area continue to deteriorate after retirement.