Isolated Word Recognition Using Pitch Pattern Information

Satoshi TAKAHASHI  Sho-ichi MATSUNAGA  Shigeki SAGAYAMA  

Publication
IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences   Vol.E76-A   No.2   pp.231-236
Publication Date: 1993/02/25
Online ISSN: 
DOI: 
Print ISSN: 0916-8508
Type of Manuscript: PAPER
Category: Speech
Keyword: 
word recognition,  pitch pattern,  accent type,  HMM,  

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Summary: 
This paper describes a new technique for isolated word recognition that uses both pitch information and spectral information. In conventional methods, words with similar phoneme features tend to be misrecognized even if their phonemes are accented differently because these methods use only spectral information. It is possible to improve recognition accuracy by considering pitch patterns of words. Many phonetically-similar Japanese words are classified by pitch patterns. In this technique, a pitch pattern template is produced by averaging pitch patterns obtained from a set of words which have the same accent pattern. A measure for word recognition is proposed. This measure based on a combination of the phoneme likelihood and the pitch pattern distance which is the distance between a pitch pattern of an input speech and pitch pattern templates. Speaker-dependent word recognition experiments were carried out using 216 Japanese words uttered by five male and five female speakers. The proposed technique reduces the recognition error rate by 40% compared with the conventional method using only phoneme likelihood.