Influence of limitations from the auditory periphery on across-channel sensitivity to amplitude modulation rate in cochlear-implant users

Individuals with cochlear implants (CIs) attain lower speech reception scores in noise relative to normal-hearing (NH) listeners. Poorer performance in CI users is partly due to reduced access to cues used to segregate sound sources, which may be limited by poor electrode-neuron interface in the auditory periphery. Poor electrode-neuron interface reduces sensitivity to temporal information at specific cochlear sites. This study investigated the influence of the periphery on discriminating differences in amplitude modulation (AM) rates presented simultaneously in two different cochlear channels. In each trial, one interval was presented and subjects chose whether AM rates were the same or different. AM rates were paired within- or across-ears. It was hypothesized that, if sensitivity to AM rate was reduced in one channel due to poor transduction of AM rate, then across-channel sensitivity would decrease. Both CI users and NH listeners participated in this experiment. Results suggest that when temporal enco...