Use of Prosody in Syntactic Disambiguation: An Analysis-by-Synthesis Approach

of seven types of structural ambiguity. In addition, it ap~ ~ ~ ~ f i ~ ~ t ~ have shown that prosody is used by human ]ispeared that the relative size and location of prosodic phrase teners to disambiguate spoken language and, in particular, that boundaries provided the principal prosodic clue for resolvthe relative size and location of prosodic phrase boundaries proing ambiguities. Thus, it seems likely that automatically vides a cue for resolving syntactic ambiguity. Therefore, autodetected prosodic phrase breaks could be used by speech matically detected prosodic phrase boundaries can provide inforunderstanding systems to reduce syntactic ambiguity. mation useful in speech understanding for choosing among several candidate parses. Here, we propose a scoring algorithm to rank candidate parses based on an analysis-by-synthesis method which compares the observed prosodic phrase structure with the predicted structure for each candidate parse. In experiments with a small corpus of ambiguous sentences spoken by FM radio announcers, we have achieved disambiguation performance close to the performance of human subjects in perceptual experiments.