Perceptual development of the categorization of the /r-w/ contrast in normal children

The present study examined the course of the perceptual development of the /r-w/ contrast. In an attempt to extend earlier research, which focused primarily on isolated age groups, data from four age-groups were gathered in the study: adults, and three, four, and five year-old children. The experimental paradigm involved a two-alternative, forced-choice identification task. The stimuli were members of a 7-step synthetic [r-w] continuum modeled after an adult male voice, varying in onset and duration of F2and F3formant transitions. Percent /w/ responses were computed and transformed to yield measures of phonemic boundaries. The significant shift in the phonemic boundary with age, as well as the increase in both the slope-steepness of the identification curve and the consistency of the responses as a function of age, indicated progressive development in phonemic perception. Results are discussed in terms of age-related changes in the auditory system and cognition.