Intensity discrimination in single and multi-electrode patterns in cochlear implants

Restricted until 5 April 2009.Single-channel psychophysics may not reflect performance with dynamic, multi-channel stimuli (e.g., speech stimuli) in cochlear implant (CI) listeners due to interactions between electrodes at the periphery or due to central processing interactions or both. The first part of the study measured single and multi-channel intensity discrimination in 5 Nucleus CI users, as functions of the relative level, electrode location and stimulation rate of the masker and probe electrodes. Spatial distance and relative stimulation levels between interleaved pairs of electrodes were found to significantly influence the degree of channel interaction. The second part of the study investigated how temporal offset between interleaved pulses may affect channel interaction at suprathreshold levels in 3 Nucleus CI users. Results showed that interactions were elevated for short temporal offsets and were reduced as the temporal offset was increased to half the stimulation period