抄録
For evaluation of diagnostic value of speech audiometry in the battery of the auditory tests for retrocochlear deafness, various types of hearing tests were presented in 73 cases with the confirmed intracranial lesions. The speech discrimination tests were performed by using three lists of the ordinary, frequency-distorted, and interrupted words, and also, the list of the synthetic vowels.
The retrocochlear disorders were differentiated from the cochlear ones by comparing the relations between the speech discrimination scores and thresholds of the pure tones, because the former shows the poor discrimination scores with mild pure tone hearing loss.
The retrocochlear lesions were classified, in more detail, according to their three sites, the acoustic nerve, brain stem, and the auditory cortex, by evaluating the findings in these test results in the affected ears. Moreover, the results of Békésy audiometry, directional audiometry, and the test of the counting ability of the tones confirmed the topological diagnosis of the retrocochlear deafness.
We supposed that the low speech discrimination scores in retrocochlear deafness were partially based on the phenomenon of the temporary threshold shift.
