Phonetic matching of auditory and visual speech develops during childhood: Evidence from sine-wave speech

摘要

The correspondence between auditory speech and lip-read information can be detected based on a combination of temporal and phonetic cross-modal cues. Here, we determined the point in developmental time at which children start to effectively use phonetic information to match a speech sound with one of two articulating faces. We presented 4- to 11-year old children (N = 77) with three-syllabic sine-wave speech replicas of two pseudo-words that were perceived as non-speech and asked them to match the sounds with the corresponding lip-read video. At first, children had no phonetic knowledge about the sounds and matching was thus based on temporal cues that are fully retained in sine-wave speech. Next, we trained all children to perceive the phonetic identity of the sine-wave speech and repeated the audiovisual matching task. Only at around 6.5 years of age, the benefit of having phonetic knowledge about the stimuli became apparent, thus indicating that AV-matching based on phonetic cues presumably develops more slowly than AV matching based on temporal cues.