Automatic generation of German pronunciation variants

The subject of this paper is a rule corpus of approx. 1500 phonetic rules that models segmental variation of pronunciation in German connected speech. The phonetic rules express on a broad-phonetic level phenomena of phonetic reduction in German that occur within words and across word boundaries. The rule corpus has been designed as a component of the Munich AUtomatic Segmentation System (MAUS), which is an HMM-based system that produces the transcription of a speech signal and corresponding segment boundaries given the orthographic representation of the concerning utterance. The fact that speech is highly variable has been taken into account using the rules to complement the statistical modelling of German speech sounds and constrain the Viterbi-search. In this paper first a short introduction to the phenomenon of variability of speech and our approach of dealing with this problem in a technical application is presented. This is followed by a formal description of the syntax of the rules and the inventory of symbols that is used. Finally, I give an outline of reduction phenomena in German and how they are represented in the phonetic rules.