Cortical Processing of Frequency Changes in Cochlear Implant Users

By Kristen Dalrymple, Communication Sciences and Disorders Advisor: Fawen Zhang Presentation ID: AM_B12 Abstract: Cochlear implant (CI) users historically have experienced difficulty in discriminating frequency changes in sound, which leads to poor speech understanding in noise. However, not much is known about how the auditory system processes these frequency changes. This study investigates how the auditory system processes frequency changes at the cortical level in CI users by examining the acoustic change complex (ACC), a type of auditory evoked potential recorded from the scalp. The ACC can be elicited by changes in acoustic features within a stimulus. Sixteen CI users completed a series of tests including a psychoacoustic test of frequency change detection, electroencephalographic (EEG) recordings, speech tests, and a questionnaire. Results showed that CI users with poorer performance in the frequency change detection task (the minimum frequency change that can be detected by the participant >10%) have poor ACCs, poorer speech performance, and lower satisfaction level of CI use, than those better performers.