Some audiological examinations, by such as Békésy's self-recording audiometry, DLSI test, speech audiometry etc., have been carried out in cases with audiograms of so called sharp cut configuration. Speech audiometry was performed by means of our new method published in Audiology Japan (1980, 1981). Steep incline portion of each audiogram was carefully examined by Békésy's audiometer which have dumping ratio of 5dB/sec. and sweep ratio of 0.5 octave/min.
The DLSI (Difference limen for short increment) values obtained from these cases remained within 1.8dB. Speech discrimination scores of the patients, examined by our new method, revealed no characteristics of retrocochlear lesions. In conclusion, neither DLSI values nor speech discrimination scores by our new method suggested retrocochlear lesions.