Pure tone audiogram were reviewed in randomly sampled 726 over 50 years of age, that had no history of trauma, ototoxic medications, noise exposure, ear surgery or family history of hearing loss, from Oct. 1980 to Sept. 1981. There were 142(male 64, female 78) in 50-54, 153(male 71, female 82) in 55-59, 136(male 61, female 75) in 60-64, 134(male 65, female 69) in 65-69 and 161 persons(male 90, female 71) over 70 years of age. The results were as follows : 1) The overall incidence of hearing loss over 26 dB was 46.0%(46.4% in male, 45.6% in female) at speech frequencies and 76.3%(81.8% in male, 71.2% in female) at high frequencies and the incidence of hearing loss was increased with aging. 2) Hearing impairment increased with advancing age at all frequencies and hearing impairment in men showed greater at high frequencies than in women. Degree of hearing loss was greater at high frequencies than at low. 3) On pure tone audiogram, the most common pattern was gradually descending pattern(49.72%) and followed by flat(26.73%) and abrupt drop pattern(21.21%). Gradually descending pattern was increased with advancing age, and abrupt drop pattern was decreased with aging. But flat pattern did not change with aging.