Acquisition of prosody: The role of variability*

Although some phonetic variability is inevitable in speech production, adult speech is fairly consistent. Thus, part of becoming a competent adult speaker is learning to appropriately limit the variability in one’s speech. It is generally believed that phonology is mastered relatively early; however, this does not take into account the refinement of articulation required to reign in the variability in production. In this paper, we investigate the development of the acoustic properties (i.e., F0, Duration, and Intensity) of two prosodic patterns of English, compound and phrasal prominence, as well as their patterns of variability, in the speech of 6-, 8-, and 11-year-olds. While the 11-year-olds show adult-like acoustic patterns in their compound prosody, no children are adult-like in phrasal prominence. Examination of the variability at the different ages shows, moreover, that even the 11-year-olds have not yet refined their speech to the same extent as adults. Thus, examination of these more subtle aspects of phonological acquisition demonstrates that the process continues for much longer than is typically assumed, and usually studied.