The course of hearing in the non-operated ears was examined in 112 female p
atients and 63 male patients with bilateral otosclerosis who had operations
in one ear only. All patients had a follow-up of at least 5 years. The mea
n annual impairment of the air conduction thresholds in the female patients
(2.0-2.5 dB/year) did not differ significantly from that of the male patie
nts (2.0-2.3 dB/year). At the last follow-up examination, no difference was
found between the sexes in the magnitude of the air-bone gaps. However, a
sensorineural component developed in the women more frequently than in the
men. Although at the last examination bone conduction thresholds of the fem
ale patients were significantly worse than those of the male patients, thes
e were not matched by age.