Effects of channel number and place of stimulation on performance with the Cochlear Corporation multichannel implant
Kileny, P.R.; Zimmerman-Phillips, S.; Zwolan, T.A.; Kemink, J.L.
American Journal of Otology 13(2): 117-123
1992
ISSN/ISBN: 0192-9763 PMID: 1599001 Document Number: 402356
The effects of active channel number and place of stimulation on auditory-only performance with the Cochlear Corporation multichannel cochlear implant were investigated in seven subjects. A balanced crossover design was employed; subjects were initially programmed with either 10 basal or the full complement of 20 to 21 active electrodes. Following a 6-month period with the initial coding strategy, subjects were programmed with the alternate configuration, which they used for an additional 6 months. Auditory-only performance on suprasegmental, phoneme (vowel and consonant) open- and closed-set speech recognition was compared between the two electrode configurations. Additionally, performance with the first configuration and performance with the second configuration 3 days following programming were also compared. While a trend for increased scores was noted with 20 electrodes, especially with open-set speech recognition tasks, none of the differences between the two configurations reached statistical significance, as indicated by a Wilcoxon test. A comparison of performance at the end of the first 6-month period and 3 days following programming with the second configuration revealed a trend for reduced scores, especially on vowel tests. Overall, our results indicate that the feature extraction coding strategy associated with the Cochlear Corporation device allows patients to function well with only 10 basal electrodes and that speech recognition is only mildly affected initially when patients are programmed with a different encoding strategy.