Auditory selective attention and speech-in-noise in cochlear implants

Abstract

Auditory selective attention is a crucial mechanism for comprehending speech in noise. We investigated if cochlear implant (CI) users exhibit auditory selective attention that involves modulation of neural responses to target speech and if such attentional ability predicts their speech-in-noise performance. In our experiment, designed to assess the strength of attentional modulation, participants with normal hearing and with CI were given a pre-stimulus visual cue that directed their attention to either of two sequences in stationary background noise and asked to select a deviant syllable. We hypothesized that the amplitude of event-related-potential (ERP) would be greater when the syllable is attended if either group is capable of employing auditory selective attention and that the difference of ERP amplitude between attended and unattended trials predicts the performance in a speech-in-noise task. Our analysis showed that the amplitude of ERPs for the attended syllable was greater than that for the unattended syllable with the CI subjects, exhibiting that attention modulates CI users’ cortical responses to sounds. Moreover, the strength of attentional modulation showed a significant correlation with the same CI users’ speech-in-noise performance. These results show that attentional modulation provides a valuable neural marker for predicting CI users’ success in real-world communications.