Large Vocabulary Continuous Speech Recognition - Berlin Chen

Word Graph Rescoring (2/6)• If word hypotheses ending at each time frame havescores higher than a predefined threshold– Their associated decoding information, such as the word startand end speech frames, the identities of current and predecessorwords, and the acoustic score, can be kept in order to build aword graph for further higher-order language model rescoring• E.g., a bigram LM was used in the tree search procedure,while a trigram LM in the word graph rescoring procedure• Keep track of word hypotheses whose scores are veryclose to the locally optimal hypothesis, but that do notsurvive due to the recombination process台 灣入 聯活 動P( 活 動 | 台 灣 入 聯 )Bigram History Assumed中 華 民 國入 聯tP( 活 動 | 中 華 民 國 入 聯 )t 3t 2t 1Speech – Berlin Chen 40