Hearing Loss and Drilling Noise

Abstract

The possible cochlear lesion caused by drilling noise was studied after simple or modified radical mastoidectomy by following the hearing of both the operated and the contralateral ear. In 29/70 cases a temporary sensorineural high tone loss of at least 10 dB in one of the frequencies 4–8 kHz was found in the operated ear; of these, 14 also showed such a loss in the contralateral ear. In addition, 2 cases showed hearing deterioration in the contralateral ear but not in the operated one, and in another case the operated ear was deaf before surgery. If bilateral, the hearing loss was generally more severe in the operated ear. Thus, there may be at least two mechanisms of inner ear lesion during chronic ear surgery: direct surgical trauma and drilling noise during the operation.