Speech intelligibility as a function of the number of channels of stimulation for normal-hearing listeners and patients with cochlear implants.
OBJECTIVE
One goal was to determine for normal-hearing listeners the number of channels of stimulation necessary to achieve a high level of speech understanding. The second goal was to determine whether patients with a six-channel cochlear implant could achieve the same level of speech understanding as normal-hearing subjects listening to speech processed through six channels.


METHODS
Speech signals were processed, for normal-hearing listeners, either in the manner of cochlear-implant processors with 2-9 fixed channels, or in the manner of a processor which picked, on each update cycle, 6 of 16 channels.


RESULTS
For the most difficult test material eight fixed channels were necessary to achieve the level of performance achieved with the "n of m" processor. Some cochlear implant patients with a six-channel continuous interleaved sampling processor achieved the same level of performance as normal-hearing subjects listening to speech via six channels.


CONCLUSIONS
A signal processor for cochlear implants with eight channels should produce the same level of intelligibility as a processor with many more channels. Processors using continuous interleaved sampling technology can provide a signal which results in the same level of speech understanding as normal, acoustic stimulation.
Dorman
M F
MF
Arizona State University, Department of Speech and Hearing Science, Tempe 85287-0102, USA.
Loizou
P C
PC
D019929:Cochlear Implantation; D003638:Deafness / Q000601:surgery*; D004558:Electric Stimulation / Q000295:instrumentation; D006309:Hearing / Q000502:physiology*; D006801:Humans; D013067:Speech Perception