Le rôle des informations visuelles dans le développement du langage de l'enfant sourd muni d'un implant cochléaire

Degradation of Labial Information Modifies Audiovisual Speech Perception in Cochlear-Implanted Children

“…In the case of A/afa/V/a∫a/ presented in VCL, CI children gave mainly visually based responses /a∫a/. This result corroborates previous findings (Schorr et al 2005;Leybaert & Colin 2007) and shows that when presented with incongruent AV stimuli, CI children base their perception mainly on the visual modality. NH children also choose the visual modality, contrary to previous findings showing a tendency of NH children to choose the auditory modality (McGurk & MacDonald 1976;Massaro 1984;Massaro et al 1986;Tremblay et al 2007).…”

“…The fact that the fusion rate was high might come as a surprise because previous studies have shown weak fusion capacities in CI children (Schorr et al 2005;Leybaert & Colin 2007). Note, however, that some of the errors made by the CI group in AO and VO conditions were consistent with the fusion responses (participants answered /ata/ on 18% of the trials in response to /apa/ in AO modality and on 9% of the trials in response to /aka/ in VO modality).…”

“…In other words, differences between visual-clear cues and visual-reduced cues were not only caused by difference in the informational content of the VO modality, but also by a supplementary auditory weight. It suggests that AV speech integration, in CI children and in NH children, is actually more an adaptive process than has been presented in previous research (Schorr et al 2005;Leybaert & Colin 2007;Rouger et al 2008). Indeed, results of both groups demonstrate that, in AV speech perception, responses are influenced by the task properties, here VR (supporting the view of Schwartz, 2010).…”

“…Perception of incongruent AV stimuli by CI children is largely biased toward the visual modality (Schorr et al 2005, Leybaert & Colin 2007. Here, we examined whether this visual bias is fixed and immutable by varying the quality of the visual speech cue and the degree of auditory proficiency.…”

“…First, several studies showed that CI children with prelinguistic deafness perform better in congruent AV modality than in auditory modality, demonstrating a significant visual gain (Lachs et al 2001;Geers et al 2003;Bergeson et al 2005). Second, a study in French using McGurk stimuli found that CI children produced mainly visually based responses to incongruent AV stimuli, whereas age-matched NH children tended to give auditory based responses (Leybaert & Colin 2007). In a study in English, Schorr et al (2005) showed that the majority of NH children (20 of 35) made consistent fusion (they reported the fusion response on ≥ 7 of the 10 trials), whereas the majority of CI children (24 of 30) made visually based responses.…”