Improving parsing by incorporating "prosodic clause boundaries" into a grammar

In written language, punctuation is used to separate main and subordinate clause. In spoken language, ambiguities arise due to missing punctuation, but clause boundaries are often marked prosodically and can be used instead. We detect PCBs (Prosodically markedClauseBoundaries) by using prosodic features (duration, intonation, energy, and pause information) with a neural network, achieving a recognition rate of 82%. PCBs are integrated into our grammar using a special syntactic category "break" that can be used in the phrase-structure rules of the grammar in a similar way as punctuation is used in grammars for written language. Whereas punctuation in most cases is obligatory, PCBs are sometimes optional. Moreover, they can in principle occur everywhere in the sentence due e.g. to hesitations or misrecognition. To cope with these problems we tested two different approaches: A slightly modified parser for word chains containing PCBs and a word graph parser that takes the probabilities of PCBs into account. Tests were conducted on a subset of infinitive subordinate clauses from a large speech database containing sentences from the domain of train table inquiries. The average number of syntactic derivations could be reduced by about 70 % even when working on recognized word graphs

Automatic classification of prosodically marked phrase boundaries in German

A large corpus has been created automatically and read by speakers. Phrase boundaries were labeled in the sentences automatically during sentence generation. Perception experiments on a subset of 500 utterances showed a high agreement between the automatically generated boundary markers and the ones perceived by listeners. Gaussian distribution and polynomial classifiers were trained on a set of prosodic features computed from the speech signal using the automatically generated boundary markers. Comparing the classification results with the judgments of the listeners yielded in a recognition rate of 87%. A combination with stochastic language models improved the recognition rate to 90%. We found that the pause and the durational features are most important for the classification, but that the influence of F0 is not neglectable

German Regional Variants - A Problem for Automatic Speech Recognition

A well known problem in automatic speech recognition (ASR) is robustness against the variability ofspeech between speakers. There are several ways to normalise different speakers; one of them is to deal with the problem of regional variation. In this paper we discuss the problem of whether moderate regional variants of German in u-ence the automatic speech recognition process and whether there is a way to improve performance through knowledge of the regional origin of the unknown speaker. The basic idea in our experiment is to cluster test speakers into distinct dialectal regions and derive observations about the typical pronunciation within these regions from a classi ed training set. In a cheating experiment where the origin of the test speakers is known we verify whether the use of the dialect-speci c pronunciation forms will improve the overall performance of the recognizer. It turns out that simply using dialect-speci c pronunciation does not signi cantly improve word accuracy on the VERBMOBIL 1996 task. 1

VERBMOBIL-ASL-SUeD: Programm-Architekturen von Systemen zur integrierten Analyse von Sprachlauten und Sprachstrukturen Abschlussbericht

Daimler-Benz worked on the areas of speech recognition, speech synthesis, and lexicon processing within the Verbmobil project. Before the project started, the automatic interpretation of speech was only investigated on very academic examples. The automatic translation of spontaneous speech has widely been seen as too futuristic. The project ASL had the preliminary goal to process speech in the environment of an automatic inquiry-system. After two years - two years earlier than planned - Verbmobil-ASL became Verbmobil. The goal of Verbmobil was the automatic translation of spontaneous speech in a restricted domain (fixing a date for an appointment). The result of the Verbmobil-ASL project consisted in the integration of a successful demonstrator together with Siemens AG. The demonstration at this project state was unplanned. The functionality of the demonstrator was the analysis of the spoken query and the re-synthesis from the logical, internal representation. We introduced the word hypotheses graph as interface between the word recognition unit and the linguistic analysis. Verbmobil had to deal with a much more complex domain and spontaneous speech. We made a very good progress in these areas as well as in the fast unsupervised speaker adaptation. Our system was integrated in the various demonstrators and successfully tested. We also use partial results of Verbmobil for new applications. (orig.)Available from TIB Hannover: F97B1758+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman

Automatic classification of prosodically marked phrase boundaries in German

A large corpus has been created automatically and read by 100 speakers. Phrase boundaries were labeled in the sentences automatically during sentence generation. Perception experiments on a subset of 500 utterances showed a high agreement between the automatically generated boundary markers and the ones perceived by listeners. Gaussian distribution and polynomial classifiers were trained on a set of prosodic features computed from the speech signal using the automatically generated boundary markers. Comparing the classification results with the judgements of the listeners yielded in a recognition rate of 87%. A combination with stochastic language models improved the recognition rate to 90%. We found that the pause and the durational features are most important for the classification, but that the influence of F0 is not neglectable. (orig.)SIGLEAvailable from TIB Hannover: RR 5221(4)+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Forschung und Technologie (BMFT), Bonn (Germany)DEGerman