Influence of lack of auditory feedback on the synchronization between preverbal vocal behaviors and motor actions: Deaf and hearing infants compaired

The present study examined the role of auditory feedback on the synchroniza tion between vocalizations and motor actions in the prelinguistic stage. Th e vocal behavior of a deaf infant was compared with that of 4 hearing infan ts in a previous study. The subject was observed at home once a month from the age of 6 to 11 months. Videotapes recorded during the observation perio d were analyzed. The results showed that synchronization between vocalizati ons and rhythmic actions occurred in the deaf infantas well as in hearing i nfants. However, the frequency of occurrence of synchronization was not so high compared to that of hearing infants. These findings suggest that audit ory feedback might have the role of promoting synchronization between vocal izations and rhythmic actions.