Chapter 6 Selectivity and Early Infant Vocalization

Abstract

Although the latin root of their age category, infans, defines young humans as incapable of speech, infants respond as communicative partners in the earliest social interactions. The study of prelinguistic vocalization provides a portrait of the interplay of biological, social and language development, spearheaded by both the infant's and the adult's predisposition to communicate together. Notwithstanding the possible communicative role of neonatal cries and vegetative sounds, vocal communication in the first 3 months of life will be the focus of this chapter. As compared with visual attention as a sign of early social development, vocalizations have been largely ignored in infancy research. Early vocal sounds are low in rate, variable in quality and highly dependent on state and contextual features. The difficulty in either studying vocalizations or using them as dependent measures of early infant development partially reflects their social selectivity. The infant's early vocal responses result from the dynamics of early motor development driven by the temporal and acoustic cues of adult interaction: babytalk. Not only do the verbal and turn-taking characteristics of babytalk attract the infant's visual attention, babytalk alters the vocal quality of the infant partner. In turn, the vocal quality of the infant alters the adult's favourable perceptions and attributions of the infant as a communicative partner. The infant not only responds vocally and selectively to babytalk, the adult responds selectively to the baby's “talk”. Infant-adult vocal exchanges represent, therefore, a bidirectional system of early communication.