Ovlivnění akustických vlastnostízevního zvukovodu exostózami

Acoustic Properties of the External Auditory CanalInfluenced by Exostoses

The authors analysed statistically audiometric investigations of bone conduction atfrequencies of 0.25, 0.5, 1, 2, 3 and 4 kHz. A group of 17 patients with exostoses in the external auditorycanal was observed. Ten subjects of the group were exposed to noise in their employment. The aimof the analysis was to compare audiometric findings in bone conduction in the observed group withthe literature dealing with hearing loss in the general population. It was found that patients withexternal auditory canal exostoses had a permanent auditory threshold shift in the range up to 2kHz, however there is no evidence of this feature in the rest of the population. The auditory thresholdshift is not dependent on noise exposure in the case-history. The authors suggest that differentacoustic characteristics of external auditory canals with exostoses could explain these audiometricfindings.

Key words:
exostosis, external auditory canal, noise-induced hearing loss, acoustics.