Place pitch discrimination and speech recognition in cochlear implant users

The considerable variability in speech perception performance among cochlear implant patients makes it difficult to compare the effectiveness of different speech processing strategies. One result is that optimal individualized processor parameter setting is not always achieved. This paper investigates the relationship between place pitch discrimination ability and speech perception to establish whether pitch ranking could be used as an aid in better patient-specific fitting of processors. Three subjects participated in this study. Place pitch discrimination ability was measured and this information was used to design new channel to electrode allocations for each subject. Several allocations were evaluated with speech tests with consonant, vowel and sentence material. It is shown that there is correlation between the perceptual pitch distance between electrodes and speech perception performance. The results indicate that pitch ranking ability might be used both as an indicator of the speech perception potential of an implant user and in the choice of better electrode configurations.