Auditory and audiovisual close-shadowing in normal and cochlear-implanted hearing impaired subjects

This study takes place in the theoretical background of perceptuo-motor linkage in speech perception. A close-shadowing experiment has been carried out on post-lingual cochlear implanted (CI) and normal-hearing (NH) adults in order to evaluate sensory-motor interactions during joint perception and production of speech. To this aim, participants have to categorize audio (A) and audiovisual (AV) syllables as quickly as possible, with two modes of responses, oral or manual. Overall, responses from NH were globally faster and more precise than those of CI, although adding the visual modality led to a gain in performance in CI. Critically, oral responses were faster but less precise than manual responses in the two groups, with a stronger difference observed for CI than for NH. Despite auditory deprivation, these results suggest the involvement of sensory-motor interactions during speech perception in CI, albeit possibly less efficient than in NH.