Acoustic characterization of the question-statement contrast in 4, 7 and 11-year-old children
Prosodic features of the speech signal include fundamental frequency (F0), intensity and duration. In order to study the development of prosody independent from segmental aspects of speech, we considered the question-statement contrast. In English, adults mark the contrast using changes in fundamental frequency, duration and intensity, with F0 being the most prominent cue. Declarative questions are marked by rising intonation whereas statements are marked by falling intonation. While previous studies have noted that young children can signal this contrast in imitative paradigms, little is known about the acoustic cues children use at different stages in development. The present study sought to provide an acoustic characterization of prosodic cues used by 12 children from three age groups, 4-year-olds, 7-year-olds and 11-year-olds, for elicited productions of declarative statements and questions. Results indicated that 4-year-olds were unable to reliably signal questions using rising fundamental frequency contour. Instead, they used increased final syllable duration to mark questions. Children in the 7-year-old group used all three cues, fundamental frequency, intensity and syllable duration, to contrast questions from statements. The oldest group relied primarily on changes in fundamental frequency and less so on intensity and duration cues. An age-related pattern is evident in that children employ different combinations of acoustic cues to mark the question-statement contrast across development. The impact of motor and cognitive-linguistic complexity on the development of prosodic control is discussed. (c) 2006 Elsevier B.V. All rights reserved.
acoustics questions children speech development prosody intonation statements acquisition