Selective production of vocalization types in different communication contexts.

This study investigates the production of vocalization in adult-infant-toy interactions from 0;4 to 0;11. The hypothesis is that vocalizations are selectively uttered in relationship to their production context. Five infants (two girls, three boys) were intensively studied. Non-segmental acoustic features of vocalizations in four communicative contexts were analysed in relation to the individual infants, in order to reveal individual differences. The data were submitted to discriminant function analysis. Results show that (a) different patterns of non-segmental features characterize sounds produced in different contexts; (b) both inter-subject differences and intra-subject consistency are observed; (c) 'selective production' disappears after 0;9. These results are discussed in relationship to sound-meaning development.