Presentation 2003/5/23
Large Vocabulary Continuous Speech Recognition using N-best Linear Lexicon Search and Tree Lexicon Search with 1-best Approximation
Norihide KITAOKA, Nobutoshi TAKAHASHI, Seiichi NAKAGAWA,
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Abstract(in English) Computational cost on a large vocabulary continuous speech recognition system based on HMM is proportional to the number of words in the vocabulary. A tree-structured dictionary is generally used to reduce the number of states of HMMs. An approximation of dependency of word boundary and likelihood on word histories is also used to suppress the increase of hypotheses in the forward procedure. We first compared the search algorithms with a tree-structured dictionary using some approximation methods and that with a linear dictionary. The algorithm based on 1-best approximation with a tree-structured dictionary is efficient but frequently looses the optimal sentence hypothesis. Linear dictionary search can find the optimal hypothesis but needs much computational cost. Thus, we propose a search method using these two algorithms in parallel. We evaluated this new search algorithm and obtained improved word recognition rate and word accuracy by 5% and 3%, respectively on read speech, and 2% and 3%, respectively on broadcast news speech.
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Keyword(in English) Large Vocabulary Continuous Speech Recognition / Search / Tree Lexicon / 1-best approximation / Linear Lexicon
Paper # SP2003-26
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Committee SP
Conference Date 2003/5/23(1days)
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Registration To Speech (SP)
Language JPN
Title (in Japanese) (See Japanese page)
Sub Title (in Japanese) (See Japanese page)
Title (in English) Large Vocabulary Continuous Speech Recognition using N-best Linear Lexicon Search and Tree Lexicon Search with 1-best Approximation
Sub Title (in English)
Keyword(1) Large Vocabulary Continuous Speech Recognition
Keyword(2) Search
Keyword(3) Tree Lexicon
Keyword(4) 1-best approximation
Keyword(5) Linear Lexicon
1st Author's Name Norihide KITAOKA
1st Author's Affiliation Toyohashi University of Technology()
2nd Author's Name Nobutoshi TAKAHASHI
2nd Author's Affiliation Toyohashi University of Technology
3rd Author's Name Seiichi NAKAGAWA
3rd Author's Affiliation Toyohashi University of Technology
Date 2003/5/23
Paper # SP2003-26
Volume (vol) vol.103
Number (no) 94
Page pp.pp.-
#Pages 6
Date of Issue