The prevalence of audiometric notches in adolescents in Germany: The Ohrkan-study.

Although there is concern about increasing hearing loss in adolescents caused by leisure noise exposure, prevalence data are scarce. In an US study, about 16-17% of adolescents were affected by audiometric notches. To estimate the prevalence of audiometric notches in adolescents in Germany, baseline data of the cohort study Ohrkan, recruitment during the school years 2009/2010 and 2010/2011 were analyzed. All students in grade 9 visiting any school in the city of Regensburg were eligible for participation. Data was collected via standardized questionnaires from students and their parents. In addition, students were asked to visit the University Clinics of Regensburg for ear examination including a tympanogram and the determination of hearing thresholds in air conduction audiometry. The prevalence of audiometric notches was determined in students with normal tympanogram in both ears and complete audiometry data. Audiometric notches were defined according to criteria used to analyse US data. Overall, 2149 students (1158 girls, 991 boys mainly aged 15-16 years) of the 3846 eligible adolescents (56%) participated. Among the 1843 adolescents with complete audiometry and tympanometry data, the prevalence of audiometric notches was 2.4% (95% confidence interval 1.7-3.1%). We could not confirm the high prevalence of audiometric notches as reported in National Health and Nutrition Examination Surveys for adolescents in the US. Differences in prevalence might be at least partly due to methodical differences in audiometry. Even if empirical evidence is presently ambiguous, it is reasonable to educate young people about the potential risks of high leisure noise exposure.