Falling intonation in the one- and two-syllable utterances of infants and preschoolers

Abstract

Previous research showed that 1-year-olds produce less pitch change in monosyllabic nuclear tones than 4-year-olds. This finding implies that infants have not acquired intonation based on a “magnitude criterion.” The present study was designed to evaluate children's early intonation development based on a “contrast criterion.” In this approach, the pitch change that infants use in final accented syllables is compared to the pitch change they use in nonfinal accented syllables. Although the absolute pitch change that infants produce is reduced relative to older children, it is possible that infants produce a wider pitch change in final than in nonfinal syllables and thereby mark a key grammatical contrast based on position-in-utterance. To test this hypothesis, one- and two-syllable utterances were acoustically analyzed in 10 English-speaking 1-year-olds and 10 4-year-olds. The results indicated that only the 4-year-olds produced intonation in accordance with the contrast criterion. Further analyses of the relation between pitch and timing supported the conclusion that 1-year-old infants do not actively control intonation to mark complete utterances.