Multimodal code-excited linear prediction (CELP) coder and metho

Details Multimodal code-excited linear prediction (CELP) coder and metho Multimodal code-excited linear prediction (CELP) coder and metho

1997-12-29

2000-11-14

Hudspeth, David R.

Data processing: speech signal processing, linguistics, language

Speech signal processing

For storage or transmission

704208, 704214, G10L 1904, G10L 1106

Patent

active

06148282&

ABSTRACT:
A multimodal code-excited linear prediction (CELP) speech coder determines a pitch-lag-periodicity-independent peakiness measure from the input speech. If the measure is greater than a peakiness threshold the encoder classifies the speech in a first coding mode. In one embodiment only frames having an open-loop pitch prediction gain not greater than a threshold, a zero-crossing rate not less than a threshold, and a peakiness measure not greater than the peakiness threshold will be classified as unvoiced speech. Accordingly, the beginning or end of a voiced utterance will be properly coded as voiced speech and speech quality improved. In another embodiment, gain-match scaling matches coded speech energy to input speech energy. A target vector (the portion of input speech with any effects of previous signals removed) is approximated using the precomputed gain for excitation vectors while minimizing perceptually-weighted error. The correct gain value is perceptually more important than the shape of the excitation vector for most unvoiced signals.

REFERENCES:
patent: 5327520 (1994-07-01), Chen
patent: 5495555 (1996-02-01), Swaminathan
patent: 5596676 (1997-01-01), Swaminathan et al.
patent: 5657418 (1997-08-01), Gerson et al.
patent: 5734789 (1998-03-01), Swaminathan et al.
patent: 5737484 (1998-04-01), Ozawa
Bishnu S. Atal and Lawrence R. Rabiner, "A Pattern Recognition Approach to Voiced-Unvoiced-Silence Classification with Applications to Speech Recognition," IEEE Trans. Acoustics, Speech, and Signal Processing, vol. ASSP-24, No. 3, p. 201-212, Jun. 1976.
Alan V. McCree, et al., "A Mixed Excitation LPC Vocoder Model for Low Bit Rate Speech Coding," IEEE, vol. 3, No. 4, pp. 242-249, Jul. 1995.
Erdal Paksoy, et al., "A Variable-Rate Multimodal Speech Coder with Gain-Matched Analysis-by-Synthesis," IEEE, vol. 2, pp. 751-754, Apr. 1997.
David L. Thomson and Dimitrios P. Prezas, "Selective Modeling of the LPC Residual During Unvoiced Frames: White Noise or Pulse Excitation," IEEE International Conference on Acoustics Speech and Signal Processing 1986 Tokyo.
Join-Hwey Chen, "Toll-Quality 16 KB/S CELP Speech Coding with Very Low Complexity," IEEE International Conference on Acoustics Speech and Signal Processing 1995 Detroit.

Affiliated with

Also associated with

Rating

Multimodal code-excited linear prediction (CELP) coder and metho does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Multimodal code-excited linear prediction (CELP) coder and metho, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Multimodal code-excited linear prediction (CELP) coder and metho will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2074927