Improvement of Speech Understanding of CI Users and Normal-Hearing Listeners through Visual Information

Audiovisual speech understanding is a complex process that relies on the individual’s ability to integrate auditory and visual information. We investigated the ability to use visual information for speech understanding in ten cochlear implant (CI) users, who solely hear with their CI and a control group of ten normal-hearing listeners (NH). Both groups were matched in terms of age and gender. A modified version of the female German matrix sentence test (OLSA) with video material of the speaker1 was used to measure speech reception thresholds of 80% speech intelligibility (SRT80) in two conditions: Audio-only (dB SNR, AO) Audiovisual (dB SNR, AV) Speechreading ability was assessed by the percentage of words identified correctly in videos of OLSA sentences without sound: Speechreading (%, SR) The visual benefit describes the change in SRT80 when visual information is added to the audio signal: Visual Benefit (dB) = SRT80(AV) – SRT80(AO) We found that CI users showed significantly higher SRT80 values in AO and AV conditions. Although SR scores did not significantly differ, CI users showed a significantly greater visual benefit compared to NH. The greater visual benefit of CI users suggests that they might have advanced integration abilities due to their history of hearing impairment. It underlines the importance of visual information for an improved speech understanding of CI users even after implantation. Audiovisual training sessions might therefore represent a valuable addition to CI rehabilitation. 1) Llorach G et al., Int J Audiol, 2022.

Deutsche Forschungsgemeinschaft (352015383)

Publication History

Article published online:
12 May 2023