Speech signal fundamental period extractor

Abstract From the Canadian patent

For an analysis of the sound source of speech a fre-, quency spectrum analysis is previously effected and the speech wave is applied to a circuit having a characteristic inverse to the frequency spectrum to make the frequency spectrum substantially flat and a residual value composed of an impulse train of the sound source or a noise is picked up and analyzed, whereby a sound source signal is extracted. For an economical construction of such a speech analyzer unneces-, sary high frequency components contained in the residual value are cut off by a low-pass filter to enable low-bits quantization of the residual value and the correlation coefficient of the residual value is utilized to thereby …