Prevalence of tinnitus and audiometric shape

Abstract

Objectives: Studies of tinnitus are often conducted on patient populations presenting for treatment. It is, however, difficult to generalise prevalence numbers and aetiological results from these studies to a healthy, elderly population. The first aim of our study was to determine the prevalence of tinnitus in an otologically screened population between 55 and 65 years old. Secondly, both prevalence and the specific characteristics of tinnitus were compared in subjects with either a flat audiogram, a high-frequency gently sloping audiogram or a high-frequency steeply sloping audiogram.

Methods: 1147 subjects (549 males and 598 females) were recruited through population registers and underwent thorough clinical and audiological examinations. Subjects who reported tinnitus in the general questionnaire about medical history and environmental exposure were invited to complete an additional questionnaire on tinnitus history.

Results: The prevalence of tinnitus was 19.3% according to the general questionnaire on medical health and environmental exposure and 11.8% according to the additional detailed tinnitus-specific questionnaire. Furthermore, our results indicate that gender has a significant effect (tinnitus is more common in males than in females), as does audiometric configuration (tinnitus is more common in subjects with a high-frequency steeply sloping audiogram than in subjects with a flat audiogram). Both effects were significant in noise-/solvent-exposed subjects, as well as in non-exposed subjects. Finally, comparison of "tinnitus characteristics" in subjects categorised by audiogram configuration revealed significant differences in loudness, pitch, temporal variability and family history of tinnitus.