NONACOUSTIC CONTRIBUTIONS TO THE PERCEPTION OF FLUENT SPEECH N.J. AUSTIN*

Phonetic ambiguities (e.g., a name/art aittt) were exciscd from semantically neutral and disambiguating sentence contexts. The isolates were used to compare the effects of item familiarity. listener expectations, syntactic context, and semantic plausibility on segmen-tation and identification of the speech stream. In Experiment 1, 36 college studcnts iden-tified 81.6 % nonambiguous controls, and 48.9 % of the ambiguous isolates. In Experiment 2, 94 students (unaware vs. preinformed of the ambiguities) listened either to isolates or to sentences that were neutral, semantically compatible, or contradictory to the reinserted isolates. Scmantic plausibility of sentences shifted perception most powerfully from the acoustic base. Item familiarity interacted with all other variables. Expectations and syntactic effects were intermediate. Results are related to conversational speech perception. Key words: phonetic ambiguities. contexts, expectation