Impact of reverberation on speech perception in users of electric-acoustic stimulation

Introduction Cochlear implant (CI) users frequently report communication problems in environments with reverberation. Users of electric-acoustic stimulation (EAS) have been shown to have better speech perception in noise compared to CI users with only electric stimulation, but speech perception in reverberation was not been investigated sufficiently. The aim of this work was to compare speech perception in reverberation of EAS and CI users under different room acoustic conditions.

Material and Methods 14 EAS users and 24 CI users and a control group of 17 normal-hearing (NH) subjects participated in the study. Speech reception thresholds (SRTs) in noise were determined adaptively for 3 different reverberation times (free field, T60=0.7 s, T60=1 s) and different spatial noise conditions.

Results The CI group showed a deterioration of SRTs with increasing reverberation time (up to 4 dB at 1 s) and statistically comparable SRTs in the EAS group. The NH group also showed a deterioration, but with 2 dB it was less than in the other groups. Neither the EAS nor the CI group could benefit from spatial separation of speech and noise in reverberation.

Summary For all subject groups, an impact of reverberation on speech perception was found even at low reverberation times, which became more pronounced with increasing reverberation time. In the test conditions with continuous noise which were investigated here, no differences in SRTs between EAS and CI groups were found.

Publication History

Article published online:
12 May 2023