Keyword Spotting by Searching the Syllable Lattices

This paper presents a keyword spotting method based on searching a syllable lattice structure. The Mandarin syllables are represented in initial-final models. By one-stage dynamic programming, an utterance is converted into a sequence of topN-candidate syllables. It comes out a syllable lattice structure for this input utterance. A vocabulary of predefined keywords is represented as a set of syllable sequences. By searching the syllable sequences of keywords in the syllable lattice structure, we can spot the keywords in the utterance. A ranking and scoring algorithm is proposed for searching the keywords. The utterance verification for non-keyword rejection is also implicitly presented in this proposed algorithm.