Identification and discrimination of synthesized syllables by normally hearing six- and ten-year-old children and by adults

Abstract

Adaptive test procedures were used to estimate: (1) boundaries between perceptual “categories” of a labeling, or identification, task and (2) the just-discriminable difference to each side of the midpoint of a 13-item /ba/-/da/-/ga/ continuum of 4-formant, synthesized syllables (AX task). At the locus of the /ba/-/da/ boundary: (1) both 10-year olds and adults had significantly better discrimination than 6-year olds; (2) 10-year-olds' categorical boundaries were significantly different from those of 6-year olds; and (3) only adults showed a significant difference between the discrimination limen and the boundary between “categories.” At the locus of the /da/-/ga/ boundary, performance of 6-year-olds differed significantly from adults'. These results were obtained even though all Ss scored approximately 100% correct on a speech discrimination test—WIPI for children and W-22 for adults—and parallel results obtained on a monosyllabic word perception task [Elliott, L. L. et al., J. Acoust. Soc. Am. 66, 12–21 (1979)]. [Supported in part by BEH, NINCDS, and NSF.]