Description:

Categoricity of segment representations depends upon word context

Exemplar theories versus rule-based theories often make opposing predictions about the nature of segment representations. Exemplar theories predict strong categoricity for segments at morpheme or word boundaries: such segments occur in many environments, so their exemplar clouds include a range of phonetic variants over which listeners can generalize. On the other hand, rule-based theories predict strong categoricity for segments that participate in contrast or phonological rules, because they interact with other segments regardless of phonetic variation. In two studies, we tested these differing predictions by asking American English listeners to judge differences among phonetic variants of consonants occurring in different word contexts: a) at morpheme boundaries without rules, b) at morpheme boundaries with rules, c) internally without rules, and d) internally with rules. Preliminary results show that listeners are less sensitive to phonetic variation when the consonant occurs at a morpheme boundary, suggesting that the representations of these consonants are more categorical, in line with the predictions of exemplar theory.