An assessment of several acoustic parameters in children's speech production development: longitudinal data

Abstract

To gain as comprehensive an understanding of children's speech production development as possible, it is important to investigate this phenomenon from a variety of complementary perspectives. The present study approached the acoustic analysis of children's speech production from two perspectives that have been less-commonly utilized in studying speech production development. First, this study was longitudinal in nature (across a period of about three years), and as such, facilitated consideration of certain questions that cannot be otherwise addressed, e.g., regarding changes across time in the speech production ofindividualchildren. Second, in order to investigate the relationships among a number of aspects of speech production development, the study assessed several different acoustic parameters in children's speech, including fundamental frequency, the first three formant frequencies of the vowel [i], and syllable duration. Seven girls were each studied at about 8.5, 10, and 11.5 years of age. The data provide information about speech production development that supplements findings previously obtained largely from cross-sectional studies. One important observation was that although the various acoustic parameters that were considered all became more adultlike across the 3 years of the study for most of the subjects, they did not all develop at the same rate or in the same fashion among the individual children. In addition, it was also observed that subjects who were most adultlike for one acoustic parameter often were not so for others, indicating that not all speech production characteristics “mature” on the same schedule for a given child.