Hearing status of French youth aged from 18 to 24 years in 1997: a cross-sectional epidemiological study in the selection centres of the army in Vincennes and Lyon

BACKGROUND: It is currently thought that young adults are at increasing risk of exposure to deleterious sources of noise. To test this possibility we have assessed hearing status of young French men aged between 18 and 24 years in 1997 and study risk factors of deafness in a cross-sectional epidemiological study at selection centres for aptitudes to National Service. METHODS: During the time of the study, 1208 subjects were examined. For each subject, data of an interview, an otoscopy and audiograms were collected. We compared hearing thresholds between subjects with different noise exposures and we determined risk factors of deafness in this population. RESULTS: The prevalence of hearing loss was 9% at medium frequencies (0.5-2 kHz) and 15% at high frequencies (4-8 kHz).We found that 60% of the subjects were regularly exposed to at least one source of loud noise. Acoustic trauma (6%) mostly explained hearing losses. Repeated episodes of otitis media in childhood (17%) also emerged as an important risk factor apparently due to increased sensitivity to noise. In subjects with antecedent of otitis media, hearing impairments were significant in personal stereo users (>1 hour per day) (p<0.001), in those who went to discos and rock concerts (>2 times per month) (p=0.01) and in those who worked in noisy places (p=0.01). In contrast, in subjects without antecedent of otitis, we found no difference in hearing thresholds between noise exposed and non noise exposed subjects. CONCLUSIONS: Loud sound exposure is a true risk factor of early deafness in subjects that had had repeated episodes of otitis media in childhood. This study stresses the need for both prevention policies and information of health professionals and practitioners.