Computational phonetics: empirical comparison

of prosodic and syntax trees


Dafydd Gibbon (Bielefeld)


Empirical study of the syntax-prosody relation is hampered by the fact that current timing models (including rhythm models) are essentially linear, while textual structure (and rhythm) is hierarchical. The present contribution describes a syntax-prosody comparison heuristic based on two new algorithms: Time Tree Induction, TTI, for building a prosodic treebank from time-annotated speech data, and Tree Similarity Indexing, TSI, for comparing syntactic trees with the prosodic trees. In a preliminary study, two parametrisations of the TTI algorithm, for different tree branching conditions, are applied to sentences taken from a read-aloud narrative, and compared with parses of the same sentences, using the TSI. In addition, null-hypotheses in the form of flat bracketing of the sentences are compared. A preference for iambic (heavy rightmost branch) grouping in English, and considerably less clear preferences for a tone language (Ibibio, Lower Cross, Nigeria) are found. The resulting quantitative evidence for syntax-prosody relations has potential applications in speech genre characterisation and in duration models for speech synthesis.