Complex stimulus processing by cochlear implant listeners

Monita Chatterjee, Scientist II, House Ear Institute, Los Angeles, CA

In this talk, I will describe experiments conducted in my lab investigating 
the detection of AM by cochlear implant listeners in the presence of 
interfering envelopes on other channels. Stimuli of interest are 
typically single-, two- or three-channel complexes of brief pulse trains,
 with different envelopes on each channel. We find that the presence of 
fluctuating maskers on other channels can significantly degrade the processing
 of modulation in the channel of interest. Results seem to indicate that the 
interference arises in a relatively central (retro-cochlear) stage of processing
 in the brain. The goal of the talk is to stimulate some discussion on the 
relevance of our findings to speech perception by cochlear implant listeners
 in the presence of competing speech or other background noise.