gms | German Medical Science

Electrical hearing with a cochlear-implant (CI) is different compared to acoustic hearing. Thus, postlingually deafened CI recipients need to learn how to recognise the new artificial input as meaningful sounds after implantation. There is increasing evidence that CI users show experience-related alterations not only in the auditory cortex but also in the interactions between the auditory and the visual system. In this talk, we are going to present several studies that provide behavioural and electrophysiological evidence of enhanced audio-visual interactions in CI users. In particular, behavioural studies suggest that the CI users have a pronounced improvement in the recognition of speech and environmental sounds when these individuals have simultaneous access to auditory and visual information [1]. This remarkable behavioural audio-visual gain in CI users is supported by event-related potentials, which show that visual stimuli have a stronger influence on auditory processing in CI users than in normal-hearing listeners [2]. It seems that this visual modulation effect on auditory processing is more pronounced in CI users with bilateral hearing loss compared to CI users with unilateral deafness [3]. Nevertheless, both groups of CI users show better lip-reading abilities and increased activation of the visual cortex during the processing of auditory and audio-visual speech stimuli when compared to normal-hearing listeners. Taken together, these results point to experience-related alterations in multisensory processing and visual enhancements which allow to compensate for the limited auditory signal provided by the CI. Supported by the Deutsche Forschungsgemeinschaft (SA 3615/1-1, SA 3615/2-1 and SA 3615/3-1).