Speech recognition and frequency discrimination with the Ineraid and CIS cochlear prostheses

Measures of frequency discrimination and speech understanding were made for cochlear implant patients using the Ineraid, analog signal processor and for patients using the continuous interleaved sampling (CIS) processor. For patients using the Ineraid, measures of frequency discrimination are significantly correlated with performance on tests of speech understanding. The correlation coefficients range from 0.60 to 0.82 depending on the frequency domain of the discrimination test and on the nature of the test of speech understanding. When Ineraid patients were fitted with a CIS processor, speech understanding improved significantly. An improvement in frequency discrimination may be the principal factor in the high word recognition scores achieved by patients using the CIS processor. [Research supported by NIDCD.]