Temporal Characteristics of Infant Vocalization during Interaction with Adults

Abstract

Objectives: This study aimed to examine the temporal characteristics of infant vocalizations during interactions with adults in natural home environments.Methods: One day LENA (Language ENvironment Analysis) recordings were collected from 20 infants aged 6 and 12 months. The collected data were analyzed by selecting 20 5-mintue intervals in the order of highest CTCs (conversational turn counts). In the analysis unit of turn-taking, interactions in which the infant responded within 0.05 seconds to 3 seconds after the adult spoke directly to the infant were regarded as one analysis unit. The temporal characteristics of infant vocalization during interactions with adults were examined through infants’ Vocalization response ratio. The temporal characteristics of infant vocalization in interactions with adults were examined by the after adults’ infant-directed speech (IDS), latency of vocalization response and overlapping vocalization ratio.Results: Infants’ Vocalization response ratio following IDS in adults did not differ significantly between the two age groups. Infants’ Vocalization response latencies increased significantly with age from 6 to 12 months. Overlapping vocalization ratio showed a significant decrease with increasing age.Conclusion: This study supports that as infants grow, they acquire temporal turn-taking skills. It also suggests that the temporal characteristics of infant vocalizations during interactions with adults may be a useful to predict infants’ language development.