ASA 127th Meeting M.I.T. 1994 June 6-10

4pSP17. Tests of the perceptual magnet effect for American English /k/ and /g/.

Katharine Davis

Patricia K. Kuhl

Dept. of Speech and Hear. Sci., WJ-10, Univ. of Washington, Seattle, WA 98195

Recent experiments from this laboratory suggest that the perceptual organization of vowel categories is strongly influenced by category goodness. Perceptual distances appear to be ``shrunk'' near best exemplars and ``stretched'' near worst exemplars. The present experiments extend these findings to consonant categories, specifically, American English /k/ and /g/. Fifteen variants of /k/ and /g/ were synthesized by independently changing voice onset time and aspiration amplitude. Adult native speakers gave goodness ratings on a seven-point scale for individual tokens and similarity ratings on a seven-point scale for pairs of these tokens. Multidimensional scaling analyses demonstrated that the perceptual space was shrunk near the best instances of these categories, primarily along the voice onset time dimension. Results were especially strong for the /k/ category, demonstrating clear within-category differences between best and worst exemplars. This suggests that the perceptual magnet effect will characterize consonant perception as well as vowel perception. Studies currently being conducted on additional cues to velar stop goodness will also be discussed. [Work supported by NIH.]