Abstract
100Hz narrow-band evoked oto-acoustic emissions (EOAEs), band-pass filtered by a 100Hz of bandwidth in frequency regions from 1.0 to 2.0KHz, were recorded from 5 cases of sudden deafness. 100Hz narrow-band EOAEs could be elicited even from ears with the hearing threshold greater than 40dB HL. Echoes with the short latency within 10msec following the stimulus onset and the frequency content 1.0 to 1.6KHz have a tendency to persist in ears with severe hearing loss. In general, the recovery of EOAEs occurred from echoes with the lower frequency content and the shorter latency, and thereafter echoes with the higher frequency content of 1.6 to 2.0KHz or the longer latency above 10 msec appeared with the improvement of hearing hearing loss. The EOAEs amplitude also increased with improving loss. The hearing loss in all five cases with definite EOAEs recovered to normal level within 20 dB HL, at least, in the frequency range between 0.125 to 0.5KHz.
