Title :
On an efficient decomposition of LPC excitation for producing natural sounding speech
Author :
Leung, S.H. ; Peng, L.F. ; Wong, O.Y. ; Chan, C.F. ; Luk, A.
Author_Institution :
Dept. of Electron. Eng., City Polytech. of Hong Kong, Kowloon Tong, Hong Kong
Abstract :
The authors present a new method of modeling the excitation of the linear predictive coding (LPC) synthesis filter at low and medium bit rates. For the speech segments with regular patterns, the excitation is composed of two sequences of pulses. The first sequence is generated in a way similar to the classical physical model that consists of a glottal filter with thinned coefficients driven by a set of pitch pulses. Both the glottal function and pitch pulses are determined using the analysis-by-synthesis technique with the mean square criterion. The auxiliary sequence consists of a few pulses to supplement the first sequence for further reducing the mean square error. For unvoiced speech segments, multipulse excitation is simply used to drive the synthesis filter. Based on real speech analysis, the model has a gain on signal-to-noise ratio (SNR) of 2-3 dB for voiced segments over the multipulse LPC using 0.8-2.5 pulses/ms
Keywords :
encoding; filtering and prediction theory; speech analysis and processing; LPC excitation decomposition; LPC synthesis filter; analysis-by-synthesis technique; auxiliary sequence; glottal filter; linear predictive coding; low bit rate; mean square criterion; mean square error; medium bit rates; multipulse excitation; natural sounding speech; pitch pulses; regular patterns; thinned coefficients; unvoiced speech segments; Bit rate; Linear predictive coding; Mean square error methods; Nonlinear filters; Predictive models; Pulse generation; Signal synthesis; Signal to noise ratio; Speech analysis; Speech synthesis;
Conference_Titel :
Computer and Communication Systems, 1990. IEEE TENCON'90., 1990 IEEE Region 10 Conference on
Print_ISBN :
0-87942-556-3
DOI :
10.1109/TENCON.1990.152626
