Mechanisms of phonological inference in speech perception.

Cross-modal priming experiments have shown that surface variations in speech are perceptually tolerated as long as they occur in phonologically viable contexts. For example, [symbol: see text] (frayp) gains access to the mental representation of freight when in the context of [symbol: see text] (frayp bearer) because the change occurs in normal speech as a process of place assimilation. The locus of these effects in the perceptual system was examined. Sentences containing surface changes were created that either agreed with or violated assimilation rules. The lexical status of the assimilated word also was manipulated, contrasting lexical and nonlexical accounts. Two phoneme monitoring experiments showed strong effects of phonological viability for words, with weaker effects for nonwords. It is argued that the listener's percept of the form of speech is a product of a phonological inference process that recovers the underlying form of speech. This process can operate on both words and nonwords, although it interacts with the retrieval of lexical information.