This study attempted to characterize the relationship between the quality and quantity of infant vocalizations and expressive/receptive vocabulary development in early childhood. Archived data from 15 parent/infant dyads was explored. Infant vocalizations from 8, 12, and 16 months of age were tallied (quantity) and coded as vegetative, reflexive, non-canonical, canonical, or linguistic (quality). Expressive/receptive vocabulary was obtained from the MacArthur-Bates Communicative Development Inventories (CDI) at 1, 2, and 3 years. Correlation and multiple regression analyses were conducted to examine the relationship between criterion and predictor variables. As the number of infant vocalizations increased, the size of expressive/receptive vocabularies increased at later ages. The more complex the infant vocalizations, the larger expressive/receptive vocabulary was at later ages. As expected, higher quantity and quality of infant vocalizations at 8, 12, and 16 months resulted in increased expressive/receptive vocabulary at 1, 2, and 3 years.
Key Words: quantity and quality of infant vocalizations, infants, vocal development, phonological development, vocabulary development, expressive vocabulary, receptive vocabulary, infant vocalizations, speech language pathology |