The Prosodic Realization of Organizational Features of Texts

This study investigates the prosodic realization of organizational features of texts. Twenty read aloud news reports were annotated according to Rhetorical Structure Theory (RST). This theory defines the clustering of elementary units (clauses) into larger segments (hierarchical organization), the relative importance of units (nuclearity) and the rhetorical relations between segments. The prosodic features we considered were pause durations between segments, pitch range and articulation rate of the segments. It was found that pause duration and pitch range reflect the hierarchical organization of a text: the lower a text segment is embedded within the hierarchy of a text, the shorter the pauses and the lower the pitch range. Also, a nuclear segment is read slower than a non-nuclear segment. Finally, rhetorical relations affect pause duration. For example, causal relations are associated with shorter pauses than non-causal relations. We conclude that the organizational features of texts as provided by RST are reflected by prosodic characteristics.