The (non) categorical perception of place assimilated coronal stops

Abstract

English coronal place assimilation generally produces gradient modification of stop place cues. Acoustic analyses are presented that show that labial assimilation of coronal stops often produces a distinctive pattern of formant movement, hereafter referred to as the coronal step. The coronal step is characterized by an initial pattern of F1, F2, and F3 movement consistent with coronal closure, followed by a second wave of movement producing formant values at offset that are intermediate between those associated with coronal and labial stops. The perceptual consequences of this pattern were examined in categorization and 4I2AFC discrimination tasks using a linear /t/-/p/ synthetic VC continuum, as well as a continuum displaying a coronal step but produced by manipulating the same acoustic parameters. The linear continuum produced data consistent with strong categorical perception, while the stepped continuum showed no evidence of categorical perception. These results are discussed in the context of a model of the perception of assimilated speech that relies on the simultaneous activation of competing phonetic categories by assimilated segments. [Work supported by the NIH.]