Use of a single channel dedicated to conveying enhanced temporal periodicity cues in cochlear implants: effects on prosodic perception and vowel identification.

The continuous interleaved sampling (CIS) strategy for cochlear implants has well-established limitations for the perception of pitch changes in speech. This study investigated a modification of CIS in which one channel was dedicated to the transmission of a temporal encoding of fundamental frequency (F0). Normal hearing subjects listening to noise-excited vocoders, and implantees were tested on labelling the pitch movement of diphthongal glides, on using intonation information to identify sentences as question or statement, and on vowel recognition. There were no significant differences between modified processing and CIS in vowel recognition. However, while there was limited evidence of improved pitch perception relative to CIS with simplified F0 modulation applied to the most basal channel, in general it appears that for most implant users, restricting F0-related modulation to one channel does not provide significantly enhanced pitch information.