Using a transcription graph for large vocabulary continuous speech recognition

A new algorithm is developed for constructing a transcription graph in large vocabulary continuous speech recognition. The transcription graph satisfies lexical constraints and encodes all high scoring phonetic transcriptions. By building a transcription graph in parallel with the word graph, we use high-level knowledge sources to constrain the paths of phonetic transcriptions such that they are created only if needed for building the word graph. This not only speeds up the search of the lexicon, but also limits the memory requirement in our system