Effects of transition length on the perception of stop consonants by children and adults.

The purpose of this investigation was to determine whether children with normal linguistic skills demonstrate increasing developmental changes in their perception of place of articulation for stop consonants with short- and long-duration formant transitions. Three experimental paradigms were used with children and adults: discrimination, labeling, and selective adaptation. Two sets of synthetic CV syllables, varying along a seven-step, bilabial-to-alveolar dimension, were used as stimuli. These two synthetic continua differed in the length of the second and third formant transitions. Results showed that children's discrimination abilities gradually approximated those of adults, but did not reach adult levels even at 10 years of age. Differences were not observed in the labeling task. Further, results of the selective adaptation task indicated that only the adult subjects showed a significant boundary shift for any adapting stimuli. The absence of selective adaptation in children was interpreted as a possible reflection of their poorer auditory abilities. Thus, the pattern of speech perception development for children for place of articulation is a complex one with a strong auditory developmental component.