Sensorineural hearing level in unilateral otosclerosis.

Preoperative bone conduction threshold measurements were made in the otosclerotic and opposite ears of 25 patients with unilateral otosclerosis to tabulate the sensorineural hearing impairment in this disease. Middle ear otosclerosis was confirmed at surgery in all cases. The bone conduction thresholds at all frequencies measured were similar in the otosclerotic and opposite ears. Adequate masking was applied to the nontest ear to measure an accurate bone conduction threshold in the test ear without producing overmasking.