[The audiograms of 462 tinnitus victims who never perceived hearing loss].

OBJECTIVE: To investigate the risk factors of tinnitus and provide evidence for tinnitus prevention. METHOD: Retrospectively analyzed the audiograms and the risk factors of 462 tinnitus victims who never perceived hearing loss, find the relationship between every risk factor and tinnitus. RESULT: The rate of tinnitus victims with high frequency hearing loss was the 46.1%, with low frequency hearing loss was 15.8%, with single middle frequency notch was 11.04%, with an audiogram like upset-basin was 7.58%, with normal audiogram was 14.07%, with other type of audiograms was 5.41%. The age distribution in the high frequency hearing loss group was mainly between 30 and 40 years, in the upset-basin hearing loss group was mainly older than 50 years, and in the other groups, mainly between 20 and 30 years. In the high frequency hearing loss group, male to female ratio was 158/55, in the low frequency hearing loss group and single middle frequency notch group ,male to female ratio was 14/59 and 12/39 respectively. In another three groups, the male to female ratio was nearly 1. Risk factors for high frequency hearing loss group, low frequency hearing loss, single middle frequency notch group and in the upset-basin hearing loss group were noise, fatigue, long-time musical instrument contact and ageing respectively. CONCLUSION: Among the tinnitus victims who never perceived hearing loss, 86% of them have hearing impairment in high frequency area, low frequency area or single middle frequency. The rate of high frequency hearing loss was 46.01%, the major risk factor was noise, most of victims were men. The rate of low frequency hearing loss was 15.8%, the major risk factor was fatigue and nervous, most of the victims were women. The rate of single middle frequency notch was 11.04%, the major risk factor was long-time musical instrument contact. The rate of upset-basin hearing loss was 7.58%, ageing was the major risk factor.