Babbling and the lack of auditory speech perception: a matter of coordination?

This paper concentrates on the question whether and where the lack of audit ory perception can be traced in the early sound productions of deaf infants . A sensorimotor description system based on movements in the phonatory and articulatory speech production systems was developed to classify early inf ant vocalizations. Canonical babbling is a strong cue in the normal speech developmental process. Therefore the main question in this work was why dea f infants do not start to babble in their first year of life like normally hearing children do. Detailed analyses of early vocalizations of deaf and h earing infants revealed that auditory feedback is needed to lead to coordin ation of movements of the phonatory and the articulatory system, and that t his coordination capacity is a prerequisite for the development of normal s peech production.