Flexible perceptual sensitivity to acoustic and distributional cues

Pronunciation variation in many ways is systematic, yielding patterns that a canny listener can exploit in order to aid perception. This work asks whether listeners actually do draw upon these patterns during speech perception. We focus in particular on a phenomenon known as paradigmatic enhancement, in which suffixes are phonetically enhanced in verbs which are frequent in their inflectional paradigms. In a set of four experiments, we found that listeners do not seem to attend to paradigmatic enhancement patterns. They do, however, attend to the distributional properties of a verb’s inflectional paradigm when the experimental task encourages attention to sublexical detail, as is the case with phoneme monitoring (Experiment 1a–b). When tasks require more holistic lexical processing, as with lexical decision (Experiment 2), the effect of paradigmatic probability disappears. If stimuli are presented in full sentences, such that the surrounding context provides richer contextual and semantic information (Experiment 3), even otherwise robust influences like lexical frequency disappear. We propose that these findings are consistent with a perceptual system that is flexible, and devotes processing resources to exploiting only those patterns that provide a sufficient cognitive return on investment.