Abstract
The effects of an input filter on the ABR threshold judgment were studied. The ABR wave form bacame smooth, and it was easy to evaluate its threshold by the high frequency cut-off at 300Hz. The ABR amplitude became greater with the low frequency cut-off at 1 to 30Hz. The threshold judgment was most favorable when the filter with 6dB/oct of slope and 30 to 300Hz band width was used. The ABR audiometries were performed on 328 cases at Kanagawa Children's Medical Center during a two and a half year period. Reliable results of behavioral audiometry were obtained from 60 cases. From the ABR data, the degree of hearing loss could be estimated as normal, mild, middle and severe. The be results agreed completely with the hearing estimation of ABR for those cases tested by COR, and 90% agreement was obtained from those tested by play audiometry.
