Prosody signals the emergence of intentional communication in the first year of life: evidence from Catalan-babbling infants.

There is considerable debate about whether early vocalizations mimic the target language and whether prosody signals emergent intentional communication. A longitudinal corpus of four Catalan-babbling infants was analyzed to investigate whether children use different prosodic patterns to distinguish communicative from investigative vocalizations and to express intentionality. A total of 2,701 vocalizations from 0;7 to 0;11 were coded acoustically (by marking pitch range and duration), gesturally, and pragmatically (by marking communicative status and specific pragmatic function). The results showed that communicative vocalizations were shorter and had a wider pitch range than investigative vocalizations and that these patterns in communicative vocalizations depended on the intention of the vocalizations: requests and expressions of discontent displayed wider pitch range and longer duration than responses or statements. These results support the hypothesis that babbling children can successfully use a set of prosodic patterns to signal intentional speech.