ASA 125th Meeting Ottawa 1993 May

5pSP6. An examination of the perceptual magnet effect.

Scott E. Lively

Speech Res. Lab., Indiana Univ., Bloomington, IN 47405

Recently, Kuhl [Pecept. Psychophys. 50, 93--107 (1991)] has argued that speech perception is guided by phonetic prototypes that are assumed to be stored in long-term memory. This claim is based on the finding of a ``perceptual magnet effect.'' According to Kuhl, speech prototypes act like ``magnets'' because they attract similar stimuli to themselves. Furthermore, prototypes attract other stimuli more strongly than nonprototypes. Thus vowels that surround a prototypical stimulus are more difficult to discriminate than vowels that surround a nonprototype. Data are presented from vowel ``goodness'' rating experiments that suggest that listeners' prototypes for the vowel /i/ may be more extreme and variable than Kuhl's data indicate. Data are also presented from a categorization experiment that indicates that all of Kuhl's vowels may not be from the same phonetic category. These findings call into question the basis of the perceptual magnet effect. An alternative interpretation of both sets of findings is given. [Work supported by NIH.]