Phonetic coherence in duplex perception: effects of acoustic differences and lexical status

A modified version of duplex perception was used to investigate the nature of perceptual organization of speech. Ss were asked to identify stimuli in which a third-formant transition was presented to 1 ear and a full syllable (base) was presented to the other ear. Phonetic integration occurred even when the spectral composition or onset frequency of the isolated transition was varied relative to the base. However, when onset asynchronies were added to spectral differences, the isolated transition ceased to contribute to the syllable percept. Lexical status of the eventual phonetic percepts also influenced the phonetic integration of acoustic components into syllable percepts. These results suggest that combinations of low-level acoustic and phonetic differences between components and higher level lexical information interact to influence the grouping of acoustic components into phonetic percepts.