Noncategorical perception of stop consonants differing in VOT

Abstract

The discriminability of bilabial stop consonants differing in VOT [voice-onset time] (the Abramson-Lisker bilabial series) was measured in a same-different task, an oddity task and a dual response, discrimination-identification task. Subjects [human] showed excellent within-category discrimination in all 3 tasks after a moderate amount of training in a same-different task with a fixed standard and with feedback. Discrimination performance continuously improved with increasing stimulus difference for both intra- and intercategory comparisons. Subjects were able to alter their identification responses so that well-defined category boundaries fell at arbitrary values determined by the experimenters. These results were not compatible with a s-rict interpretation of the categorical perception of stop consonants.