The P300 Auditory Event-Related Potential May Predict Segregation of Competing Speech by Bimodal Cochlear Implant Listeners

Abstract

Compared to normal-hearing (NH) listeners, cochlear implant (CI) listeners have greater difficulty segregating competing speech. Neurophysiological studies have largely investigated the neural foundations for CI listeners' speech recognition in quiet, mainly using the P300 component of event-related potentials (ERPs). P300 is closely related to cognitive processes involving auditory discrimination, selective attention, and working memory. Different from speech perception in quiet, little is known about the neurophysiological foundations for segregation of competing speech by CI listeners. In this study, ERPs were measured for a 1 vs. 2 kHz contrast in 11 Mandarin-speaking bimodal CI listeners and 11 NH listeners. Speech reception thresholds (SRTs) for a male target talker were measured in steady noise or with a male or female masker. Results showed that P300 amplitudes were significantly larger and latencies were significantly shorter for the NH than for the CI group. Similarly, SRTs were significantly better for the NH than for the CI group. Across all participants, P300 amplitude was significantly correlated with SRTs in steady noise (r = −0.65, p = 0.001) and with the competing male (r = −0.62, p = 0.002) and female maskers (r = −0.60, p = 0.003). Within the CI group, there was a significant correlation between P300 amplitude and SRTs with the male masker (r = −0.78, p = 0.005), which produced the most informational masking. The results suggest that P300 amplitude may be a clinically useful neural correlate of central auditory processing capabilities (e.g., susceptibility to informational masking) in bimodal CI patients.

Pre-attentive fundamental frequency processing in Mandarin-speaking children with cochlear implants as revealed by the peak latency of positive mismatch response

“…Secondly, given the very young age of children, the “attentive” F0 contour and level processing tasks were not performed in the current study, which limited the comparison for current findings with the previous ones. Thirdly, lots of previous studies have demonstrated that acoustic hearing experience or low frequency residual hearing level significantly correlated with pitch perception performance ( Tao et al, 2015 , 2018 , 2022 ; Liu et al, 2019 ). However, the detailed aided and unaided hearing thresholds were not well documented across all children in this study, making it difficult to investigate the relationship between hearing level and neural responses to F0 change.…”