Place-pitch discrimination of single- versus dual-electrode stimuli by cochlear implant users (L).
Simultaneous or near-simultaneous activation of adjacent cochlear implant electrodes can produce pitch percepts intermediate to those produced by each electrode separately, thereby increasing the number of place-pitch steps available to cochlear implant listeners. To estimate how many distinct pitches could be generated with simultaneous dual-electrode stimulation, the present study measured place-pitch discrimination thresholds for single- versus dual-electrode stimuli in users of the Clarion CII device. Discrimination thresholds were expressed as the proportion of current directed to the secondary electrode of the dual-electrode pair. For 16 of 17 electrode pairs tested in six subjects, thresholds ranged from 0.11 to 0.64, suggesting that dual-electrode stimuli can produce 2-9 discriminable pitches between the pitches of single electrodes. Some subjects demonstrated a level effect, with better place-pitch discrimination at higher stimulus levels. Equal loudness was achieved with dual-electrode stimuli at net current levels that were similar to or slightly higher than those for single-electrode stimuli.
Donaldson
Gail S
GS
Clinical Psychoacoustics Laboratory, Department of Otolaryngology, University of Minnesota, MMC 396, Rm 8-323 PWB, 420 Delaware Street SE, Minneapolis, Minnesota 55455, USA. gdonalds@cas.usf.edu
Kreft
Heather A
HA
Litvak
Leonid
L
D000368:Aged; D003054:Cochlear Implants; D003638:Deafness / Q000628:therapy*; D004558:Electric Stimulation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010898:Pitch Perception / Q000502:physiology*