Duration and the prosodic disambiguation of nested structure

Durational information provides strongly reliable cues for organizing and tracking syntactic structure of sentences. At the same time, durational properties of speech are largely dependent on complexity, often modelled as a function of predictability: higher predictability is reliably associated with shorter duration, while less predictable elements of utterances are more carefully articulated, and thus produced more slowly. While the two determinants of duration (structure and predictability) are often aligned, there exist a well-defined set of exceptions where the two factors make opposite predictions. We discuss converging evidence that rhythm modulation might play a crucial role in the disambiguation of structural nesting, leading to shorter duration for more complex nested structures and longer duration for simpler structures involving sisterhood. We then present an account of these durational differences and rhythmic patterns, based on the interaction of independently motivated prosodic principles.