No abstract

Young children are slow to master conventional intonation patterns in their yes/no questions, which may stem from imperfect understanding of the links between terminal pitch contours and pragmatic intentions. In Experiment 1, five- to ten-year-old children and adults were required to judge utterances as questions or statements on the basis of intonation alone. Children eight years of age or younger performed above chance levels but less accurately than adult listeners. To ascertain whether the verbal content of utterances interfered with young children's attention to the relevant acoustic cues, low-pass filtered versions of the same utterances were presented to children and adults in Experiment 2. Low-pass filtering reduced performance comparably for all age groups, perhaps because such filtering reduced the salience of critical pitch cues. Young children's difficulty in differentiating declarative questions from statements is not attributable to basic perceptual difficulties but rather to absent or unstable intonation categories.

The present study compared children's and adults' identification and discrimination of declarative questions and statements on the basis of terminal cues alone. Children (8-11 years, n = 41) and adults (n = 21) judged utterances as statements or questions from sentences with natural statement and question endings and with manipulated endings that featured intermediate fundamental frequency (F) values. The same adults and a different sample of children (n = 22) were also tested on their discrimination of the utterances. Children's judgments shifted more gradually across categories than those of adults, but their category boundaries were comparable. In the discrimination task, adults found cross-boundary comparisons more salient than within-boundary comparisons. Adults' performance on the identification and discrimination tasks is consistent with but not definitive regarding categorical perception of statements and questions. Children, by contrast, discriminated the cross-boundary comparisons no better than other comparisons. The findings indicate age-related sharpening in the perception of statements and questions based on terminal F cues and the gradual emergence of distinct perceptual categories.