Speech Discrimination and Monaural Filtered Speech Tests for Temporal Lobe Lesions

Central auditory functions of 7 cases of unilateral temporal lobe lesion were examined. The speech discrimination scores were nearly normal in the ipsilateral ears, but reduced in the contralateral ears in five out of six cases. The monaural filtered speech tests, which consisted of nonsense onesyllable words filtered through 1, 200 and 1, 700Hz low pass and high pass filters, were performed on five cases.One case consistently showed lower scores to all low pass and high pass filtered speech sounds in the contralateral ears. Two cases showed lower scores in 3 out of 4 lists, but the rest of two cases showed nearly normal scores.Those results showed that the filtered speech tests of the present studies did not enhance the reduction of discrimination scores in the contralteral ear to temporal lobe lesions, and the further studies are needed for development of the word lists and cut-off frequency of filter.