ACOUSTIC CORRELATES OF STRESS IN YOUNG CHILDRENS SPEECH

This study examined the acoustic correlates of stress in children's pr oductions of familiar words. Previous research has employed experiment al words rather than familiar words to examine children's phonetic mar king of stress, or has not adequately controlled for phonetic environm ent. Subjects in this study included 22 children, aged 18-30 months, a nd 6 adults. Fundamental frequency, duration, and amplitude measures w ere extracted from stressed and unstressed syllables in two types of c omparisons: one that controlled phonetic environment and syllable posi tion (interword) and one that measured the relative effects of stress within the same word (intraword). When the tokens were analyzed on the basis of target stress pattern, results revealed no differences betwe en adults and children in their acoustic marking of stress. Listener j udgments showed that approximately 30% of children's two-syllable prod uctions were coded unreliably or were perceived as inaccurately stress ed. Overall findings indicate that children control fundamental freque ncy, amplitude, and duration to derive perceptually identifiable stres s contrasts in the majority of their productions but they are not comp letely adult-like in their marking of stress.