Single-channel versus multichannel electrical stimulation. Voicing-frequency and formant-transition difference limens.
The 'frequency' processing ability of 11 cochlear-implant patients wearing the Symbion device was evaluated with the stimuli presented in a multichannel mode and in a single-channel mode. A fixed-formant synthetic vowel /a/ was used to measure voicing-frequency difference limen. A voiced, synthetic single formant was used to measure the formant-transition difference limen. On the voicing-frequency test, patients obtained a median difference limen of 8 Hz when stimuli were presented in the multichannel mode and 14.7 Hz in the single-channel mode. On the formant-transition test, patients obtained a median difference limen of 589 Hz in the multichannel mode and 611 Hz in the single-channel mode. Three patients were unable to obtain a difference limen within the range of available stimuli. The performance with multichannel stimulation was significantly better (lower difference limen) than performance in the single channel stimulation. Temporal information in more channels and place information may contribute to the superior performance with multichannel stimulation.
Kuk
F K
FK
Department of Otolaryngology-Head & Neck Surgery, University of Iowa, Iowa City.
D003054:Cochlear Implants; D004558:Electric Stimulation / Q000379:methods*; D006801:Humans; D010699:Phonation; D011474:Prosthesis Design; D014831:Voice