Unilateral otosclerosis and noise-induced occupational hearing loss.

The interaction between noise-induced hearing loss and otosclerosis remains unclear and controversial. In the present study, the effect of chronic noise exposure was examined in 31 patients with unilateral otosclerosis. Consideration was given to hearing loss at specific frequencies, the influence of age, and the effect of the size of the air-bone gap. A small, though statistically significant, protective effect of otosclerosis was demonstrated at 4 kHz. This effect was maintained despite advancing age. An apparent inverse relationship was found between the amount of hearing loss and the size of the air-bone gap at 4 kHz, but multiple linear regression analysis suggested that this finding was contaminated by age effects.