Speech Sciences (음성과학)
- Volume 11 Issue 2
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- Pages.259-269
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- 2004
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- 1226-5276(pISSN)
Excitation Enhancement Based on a Selective-Band Harmonic Model for Low-Bit-Rate Code-Excited Linear Prediction Coders
저전송률 코드여기 선형 예측 부호화기를 위한 선택적 대역 하모닉 모델 기반 여기신호 개선 알고리즘
Abstract
In this paper, we propose a new excitation enhancement technique to improve the speech quality of low bit-rate code-excited linear prediction (CELP) coders. The proposed technique is based on a harmonic model and it is employed only in the decoding process of speech coders without any additional bits. We develop the procedure of harmonic model parameter estimation and harmonic generation, and apply this technique to a current state-of-the-art low bit rate speech coder, ITU-T G.729 Annex D. Also, its performance is measured by using the ITU-T P.862 PESQ score and compared to those of the phase dispersion filter and the long-term postfilter applied to the decoded excitation. It is shown that the proposed excitation enhancement technique can improve the quality of decoded speech and provide better quality for male speech than other techniques.