Relations between prosodic variables and communicative functions.

Three children were observed interacting with their mothers at three different times: before the onset of single words, when vocabulary consisted of 10 words, and when vocabulary consisted of 50 words. Relations between communicative functions and acoustic analyses of prosodic variables (i.e. rise vs. nonrise of terminal contours) were studied. Considerable variability was found among the children in the number of rises produced overall and those produced for any function. Each child's use of rise was fairly constant over time and rises were produced relatively more frequently than nonrises with functions requiring a response from the listener. Factors affecting similarities and differences are discussed.