Acoustical study of the development of stop consonants in children

Abstract

This study focuses on the acoustic patterns of stop consonants and adjacent vowels as they develop in young children (ages 2.6–3.3) over a 6-month period. The acoustic properties that are being measured for stop consonants include spectra of bursts, frication noise and aspiration noise, and formant movements. Additionally, acoustic landmarks are labeled for measurements of durations of events determined by these landmarks. These acoustic measurements are being interpreted in terms of the supraglottal, laryngeal, and respiratory actions that give rise to them. Preliminary data show that some details of the child’s gestures are still far from achieving the adult pattern. The burst of frication noise at the release tends to be shorter than adult values, and often consists of multiple bursts, possibly due to greater compliance of the active articulator. From the burst spectrum, the place of articulation appears to be normal. Finally, coordination of closure of the glottis and release of the primary articulator is still quite variable, as is apparent from a large standard deviation in VOT. Analysis of longitudinal data on young children will result in better models of the development of motor speech production. [Work supported by NIH Grants DC00038 and DC00075.]