Quantifying division of labour: Effects of clause type on intonational meaning

• The shape of sentence-final contours has largely analogous effects across declaratives and interrogatives • Excursion and duration can affect perception of speaker confidence and response expectation • Clause type sets expectations for intonational contours • Findings support a fully compositional division of labour between prosody and syntax if we associate clause types with particular conversational effects This paper reports quantifiable evidence for a clean division of labour between syntax and prosody in deriving the meaning of rising intonation. This evidence stems from two perception studies that asked participants to rate the speaker attitudes and their response expectation expressed by rising declaratives and interrogatives. Rises were manipulated by changing pitch excursion and duration which are known to affect their interpretation. One part in each study addressed the relation between the contour shape and the perception of speaker confidence or certainty, another part addressed the relation between the contour shape and the perception of response expectation. The two studies differed in whether the rise was paired with a declarative or an interrogative clause. Across clause-types, higher excursion led to lower ratings of speaker confidence/certainty and higher ratings for response expectation. For declaratives only, large duration differences also affected ratings of speaker confidence. While the patterns emerging about prosodic form-function mapping were similar across clause types, the effect sizes differed notably. This suggests that duration and excursion have clause-type-independent effects, which are moderated by default expectations of contour and clause-type combinations. Such an interpretation supports previous compositional accounts of intonational meaning that ascribe independent functions to clause type and intonation, each contributing to their conversational effects.