Dissertation defended (April 18, 2012) and submitted (May 3, 2012). Degree to be conferred August 17, 2012.
Download the Dissertation: Discourse Prosody in Production and Perception
Dissertation Abstract: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 dissertation explores the relationship between prosody and discourse in production and perception, helping to identify what information about the structure of discourse is in speakers’ prosody and what prosodic variation listeners use in discourse interpretation.
First, a production study examines prosodic correlates of discourse structure in readings of a newspaper article. Prosodic measures of pause duration, pitch, intensity and speech rate were correlated with discourse structural measures of boundary size, discourse coordination/subordination, and their interaction. Results showed significant correlations between the prosodic measures and both structural measures and their interaction. This interaction 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.
Then, a series of perception studies examine the ability of synthesized manipulations of prosody to bias the interpretation of ambiguous discourse. For example, the discourse “I sat in on a history class. I read about housing prices. And I watched a cool documentary” could be interpreted as describing three separate, independent events (coordinated interpretation) or that the events of the second and third sentences took place during the event of the first (subordinated interpretation). Results show rising pitch at the end of the first sentence led to more coordinated interpretations compared to falling pitch.
These results are taken to suggest that one meaning for rising pitch is as a marker of discourse coordination. This proposal is motivated by research on listing intonation. The potentially contradictory claim by Pierrehumbert & Hirschberg (1990) that high terminal pitch indicates elaboration, a subordinating relation, is discussed and re-analyzed to bring their data in line with these results. Then, these results are discussed with respect to prosodic disambiguation of syntax, and comparisons are made between prosodic disambiguation of syntactic and discourse structures.