PROSODY AND FOCUS IN SPEECH TO INFANTS AND ADULTS

Two studies investigated adults' use of prosodic emphasis to mark focused words in speech to infants and adults. In Experiment 1,18 mothers told a story to a 14-month-old infant and to an adult, using a picture book in which 6 target items were the focus of attention. Prosodic emphasis was measured both acoustically and subjectively. In speech to infants, mothers consistently positioned focused words on exaggerated pitch peaks in utterance-final position, whereas in speech to adults prosodic emphasis was more variable. In Experiment 2, 12 women taught another adult an assembly procedure involving familiar and novel terminology. In both studies, stressed words in adult-directed speech rarely coincided with pitch peaks. However, in infant-directed speech, mothers regularly used pitch prominence to convey primary stress. The use of exaggerated pitch peaks at the ends of utterances to mark focused words may facilitate speech processing for the infant.