Auditory selective attention in cochlear implant users

• DOI: 10.1121/1.4969462
• Publication Date: 2016-11-18T18:02:34Z
• Authors: Inyong Choi; Subong Kim; Phillip E. Gander
• Keywords: 0103 physical sciences; 01 natural sciences

Selective attention is a fundamental process for our communication in noisy everyday environments. Previous electrophysiologic studies have shown that selective attention modulates the neural representation of the auditory scene, enhancing responses to a target sound while suppressing the background. Given that most cochlear implant (CI) users complain about difficulty understanding speech within background noise, we investigated whether CI users' selective attention performance and underlying neural processes are 1) degraded compared to normal-hearing (NH) listeners and 2) variable among individuals. Using speech stimuli recorded from two competing speakers (male and female), we measured 12 CI and 17 NH listeners' selective attention performance while their cortical neural processes were simultaneously recorded with high-density electroencephalography. While both groups showed above-chance level performance and significantly larger evoked responses to attended stimuli in auditory cortex, the CI group's selective attention performance and neural gain control were poorer than those of NH listeners. Furthermore, a positive correlation was found between the attentional modulation of evoked cortical responses and behavioral performance in the CI group. This result suggests that degraded selective attention processes contribute to an explanation of CI users' difficulty in real-world communication.