PURPOSE: To evaluate the clinical and audiometric characteristics of occupational hearing loss induced by noise, according to age and time of exposition in years. METHODS: 222 patients with occupational sensoriumneural hearing loss induced by noise were studied retrospectively, correlating the auditive clinical claims, alterations of audiometric thresholds at frequencies of 250Hz to 8000Hz, speech discrimination indicator with age and time of exposure. As a control group were used the audiometric threshold of a population of same medium age, without morbid antecedents of hearing illness, as preconized by ISO 1999 (1990). The group were divided into subgroups and three decades of exposure were analyzed. RESULTS: It was verified that the clinical claims of hipoacusy increases according to the age and time of exposure. The frequency of tinnitus is constant. The audiometric thresholds in the second decade of exposure present variations that depend on the age. The several audiometric curves are parallel, but they are not horizontal. The worst thresholds were found in the high frequencies from 3000Hz to 8000Hz, as a clinical and physiopathological consequences of the commitment of basal areas of cochlea. The speech discrimination showed to be worst according to the increase of age and time of exposure. CONCLUSION: Patients with hearing loss disacusy induced by occupational noise present characteristic audiometric thresholds that varie according to age and time of exposure to noise. These characteristics defined and resumed in audiometric curves can constitute a standard of comparation, evaluation and control for exposed populations.
Noise induced hearing loss; Hipoacusy; Epidemiology
