Electrode position, repetition rate, and speech perception by early- and late-deafened cochlear implant patients.
Psychophysical and speech perception studies were conducted on eight patients using the 22-electrode cochlear implant manufactured by Cochlear Pty. Ltd. Four early-deafened patients became deafened at 1-3 years of age and were implanted at 5-14 years of age. Four late-deafened (postlingual adult) patients became deafened at 38-47 years of age and were implanted at 42-68 years of age. Psychophysical studies measured the discrimination of trajectories with time-varying electrode positions and repetition rates. Speech perception studies measured performance using two speech coding strategies: a multi-electrode strategy which coded the first and second formant frequencies, the amplitudes of the two formants, and the fundamental frequency; and a single-electrode strategy which coded the amplitudes of the first and second formants, and the fundamental frequency. In general, the four late-deafened patients and one early-deafened patient were more successful than the other three early-deafened patients in the discrimination of electrode position trajectories and in speech perception using the multi-electrode strategy. Three of the four late-deafened patients were more successful than the early-deafened patients in the discrimination of repetition rate trajectories. Speech perception performance in the single-electrode strategy was closely related to performance in repetition rate discrimination. The improvement in speech perception performance from the single-electrode to multi-electrode strategy was consistent with successful performance in electrode discrimination.
Busby
P A
PA
Department of Otolaryngology, University of Melbourne, Parkville, Victoria, Australia.
Tong
Y C
YC
Clark
G M
GM
D000161:Acoustic Stimulation; D000293:Adolescent; D000328:Adult; D000368:Aged; D002675:Child, Preschool; D003051:Cochlea / Q000503:physiopathology / Q000601:surgery; D003054:Cochlear Implants; D004558:Electric Stimulation; D005260:Female; D006319:Hearing Loss, Sensorineural / Q000209:etiology / Q000503:physiopathology / Q000534:rehabilitation*; D006801:Humans; D007802:Language; D007807:Language Tests; D008297:Male; D008875:Middle Aged; D010775:Photic Stimulation; D011601:Psychophysics; D013067:Speech Perception