Acoustical characteristics of sound production of deaf and normally hearing infants

Several recent studies have shown that speech production develops in an organized way, already in the first twelve months of life. This development is determined by several factors such as anatomical growth and physiological constraints. Studying the sound production of deaf infants and comparing this with that of normally hearing infants, can give more insight into the role of auditory speech perception on sound production. So far, no systematic work has been reported on the development of sound production of deaf infants in the first months of life. The present study is intended to address this topic in a systematic and controlled way. Preliminary results indicate differences in sound production between deaf and normally hearing infants, for instance with respect to utterance duration, even within the first half year of life. These findings strongly suggest that already in this early stage of speech development sound production is not solely determined by anatomical and physical constraints, but also by auditory perception and feedback. These results may contribute to a better understanding of the current models of early speech acquisition.