Electrical audio signal processing systems and devices – One-way audio signal program distribution – Public address system
Patent
1983-04-13
1988-03-15
Kemeny, Emanuel S.
Electrical audio signal processing systems and devices
One-way audio signal program distribution
Public address system
G10L 500
Patent
active
047318465
ABSTRACT:
A voice messaging system, wherein linear predictive coding (LPC) parameters, pitch, and preferably other excitation information is derived from a human voice input, encoded, and transmitted and/or stored, to be called up later to provide a speech output which is nearly identical to the original speech input. The invention features adaptive filtering of the residual signal. The residual signal derived from LPC estimation is adaptively filtered, and then is used as the input to a conventional pitch estimation procedure. The adaptive filtering step uses the first reflection coefficient (k.sub.1) to realize a simple filter (e.g., A(z)=(1-k.sub.1 z.sup.-1).sup.-1. This filter removes high frequency noise from the residual signal during voiced periods, but does not remove the high frequency energy which contains important information during the unvoiced periods of speech. Preferably the above preprocessing technique is also combined with a postprocessing technique, wherein dynamic programming is used to optimally track pitch and voicing information through successive frames.
REFERENCES:
patent: 3975587 (1976-08-01), Dunn et al.
patent: 3979557 (1976-09-01), Schulman et al.
patent: 4044204 (1977-08-01), Wolnowsky et al.
patent: 4220819 (1980-09-01), Atal
patent: 4360708 (1982-11-01), Taguchi et al.
patent: 4472832 (1984-09-01), Atal et al.
patent: 4516259 (1985-05-01), Yato et al.
patent: 4561102 (1985-12-01), Prezas
"A Linear Prediction Vocoder Simulation Based upon the Autocorrelation Method"--Markel et al., IEEE Transactions on Acoustics, Speech, and Signal Processing, vol. ASSP-22, No. 6, pp. 124-134 (Apr. 1974).
"A Pitch Extraction Algorithm Based on LPC Inverse Filtering and AMDF"--Un et al., IEEE Transactions on Acoustics, Speech, and Signal Processing, vol. ASSP-25, No. 6, pp. 565-572 (Dec. 1977).
"Epoch Extraction from Linear Prediction Residual for Identification of CLosed Glottis Interval"--Ananthapadmanabha et al., IEEE Transactions on Acoustics, Speech, and Signal Processing, vol. ASSP-27, No. 4, pp. 309-319 (Aug. 1979).
Doddington George R.
Secrest Bruce G.
Hiller William E.
Kemeny Emanuel S.
Merrett N. Rhys
Sharp Melvin
Texas Instruments Incorporated
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