[Analysis of 255 cases of occupational hearing loss]

The authors analyzed 255 cases of occupational hypacusia reported as occupational diseases in 1962-1988 in the Czechoslovak uranium industry. Up to 1975 occupational hypacusias accounted for 9-11% of the nationwide number of hypacusia notified as occupational diseases. Due to extensive social provisions, incl. preventive ones, the incidence declined since 1985 below 1% of the nationwide incidence. The group of 255 men with occupational hypacusia was examined in detail at the Health Centre of the Uranium Industry in Príbam. Their age is 49.0 +/- 8.5 years, noise exposure 14.6 +/- 5.8 years, the the ratio of miners is 82.4%, the total percentage hearing loss is 63.5 +/- 11.4%, the mean annual increment of the total percentage hearing loss is 4.8 +/- 0.6%, the greatest mean annual increment is 5.4% in the occupation of miners.