Analysing the correspondence between automatic prosodic segmentation and syntactic structure

Prosody and syntax are highly related, even if the prosodic structure cannot be directly mapped to the syntactic one and vice versa. This paper presents an experiment for exploring in what degree a powerful HMM-based automatic prosodic segmentation tool can recover the syntactic structure of an utterance in speech understanding systems. Results show that the approach is capable of recalling up to 92% of syntactic clause boundaries and up to 71% of embedded syntactic phrase boundaries based on the detection of phonological phrases. Recall rates do not depend further on the syntactic level (whether the phrase is multiply embedded or not), but clause boundaries can be well separated from lower level syntactic phrases based on the type of the aligned phonological phrase(s). These findings can be exploited in speech understanding systems, allowing for the recovery of the skeleton of the syntactic structure, based purely on the speech signal.