Production of lexical stress patterns in bi- and tri-syllabic words by five-year-old children was investigated. Duration and amplitude, which are the primary acoustic correlates of lexical stress in American English, were examined in words produced in isolation, in utterance-initial and utterance-final positions. In all three prosodic environments, children and adults differentiated lexical stress patterns by varying relative rhyme durations in the words. The difference between children and adults was observed in amplitude patterns within each word type. The amplitude patterns of adults varied as a function of prosodic position, whereas children tended to have similar amplitude patterns in words produced in isolation and in utterance-final position. These results suggest that the position of a word in an utterance influences the intersyllabic amplitude pattern in the word. Children may acquire amplitude patterns in utterance-final words later than in utterance-initial words, possibly due to a larger degree of pattern variation in the former rather than the latter position.

Index Terms: child speech, lexical stress patterns, prosodic position, duration, amplitude