Prosodic correlates of discourse boundaries and hierarchy in discourse production

⿢Speakers read aloud a newspaper article annotated for discourse structure.⿢Correlation analyses identify independent predictors and prosodic measures.⿢Boundary size, coordination/subordination and their interaction predict prosody.⿢Pitch and intensity are higher and pause duration longer after larger boundaries.⿢Interaction of boundary size and hierarchy after small, but not large, boundaries.

A well-formed discourse is more than just a series of well-formed sentences. While often left implicit, this structure to discourse is sometimes overtly cued. And though most attention in this area has focused on lexicalized cues like discourse markers, prosody can also convey information about the structure of discourse. This paper presents the results of a production study examining prosodic correlates of discourse structure in readings of a newspaper article. Prosodic measures of pause duration, pitch, intensity and speech rate were found to significantly correlate with discourse structural measures of boundary size, discourse coordination/subordination, and their interaction. This interaction effect shows that the effect of boundary size on an utterance's prosody often depends on whether that utterance is coordinated or subordinated, and vice versa. These results expand our understanding of how prosody correlates with discourse structure, setting the stage for follow-up perception studies of what prosodic variation listeners use in discourse interpretation.