Anticipatory and carry-over laryngeal coarticulation in 5-year-old children and adults.

Abstract

Many studies have compared the time course of coarticulation between children and adults. Most of this work has assessed supralaryngeal aspects of articulation. However, laryngeal coarticulation also occurs, as evident in measures of fundamental frequency (f0) and voice source features in vowels flanking voiceless consonants. Moreover, most developmental work has focused on anticipatory coarticulation, which is thought to reflect planning. In contrast, carryover coarticulation is thought to result mainly from articulatory inertia. Thus, the two forms of coarticulation may show different developmental time courses. This work evaluates laryngeal coarticulation in typically developing 5-year-old English-speaking children and adult females via measures of oral airflow. Speakers produced approximately 25 repetitions each of intervocalic /b p h/, with the target consonant initiating a stressed syllable. From the airflow signal, pulse-by-pulse measures were made of the smoothed airflow (DC flow), the pulse amplitude (AC flow), and f0 before and after the target consonants. Previous analyzes of a subset of these data indicated that carryover coarticulation in children was highly variable from token to token, complicating age comparisons based on average measures. Of particular interest here is whether the degree of coarticulatory variability differs depending on direction (anticipatory versus carryover).