Abstract:

Several psychophysical procedures have been proposed as measures of channel interaction in subjects implanted with a multichannel cochlear prosthesis. In order to compare these different measures of channel interaction, and to assess their impact on speech recognition, two psychophysical procedures were performed to measure the forward masking and electrode discrimination patterns elicited by electrical stimulation in subjects implanted with the Nucleus device. In this study, forward masking was measured for all combinations of the masker and probe electrodes. These results are presented and compared with the electrode discrimination data. The masking patterns are also compared to those described by Lim et al. [J. Acoust. Soc. Am. 86, 971--980 (1989)] and by Shannon [R. V. Shannon, Hear. Res. 12, 1--16 (1983)]. Speech recognition data are also presented, and the relationship between channel interaction and speech recognition is explored. Finally, since the Nucleus device stimulates electrodes sequentially from base to apex, the potential loss in transmitted information that is indicated by the channel interaction data is discussed. [Work supported by NIH.]