Avoidance of Stress Clash in Perception of Conversational American English

We examine evidence for a regularity bias in the perception of sentence-level stress patterns, asking to what degree listeners perceive speech as metrically regular, with few or no occurrences of stress clash. We assess regularity through a stress perception task carried out by untrained listeners annotating transcripts of recorded speech, with sentences designed to have regular stress, and sentences drawn from a corpus of spontaneous conversational speech. Results show listeners report perceiving fewer stress clashes than predicted by random placement of stresses or by concatenating the citation form stress patterns of each individual word in a given sentence, though some incidence of stress clash is reported for both the regular and irregular speech materials. These findings suggest that listeners perceive English speech in accordance with a weak regularity bias. Inter-transcriber agreement rates also reveal substantial disagreement in perceived stress patterns at the sentence level, for regular and irregular sentences alike, suggesting variability in the perception of acoustic cues to stress at these levels.