Speech recognition by polarized linear predictive error coding—POLPEC method
Masato Akagi, Taizo Iijima · Electronics and Communications in Japan (Part I Communications) · 1982
Abstract This paper describes the polarized linear predictive error coding method (POLPEC), which is a new scheme for speech recognition. Although the residual waveform power method, which is a method of speech recognition using an inverse vocal tract filter, has the advantage that the processing for recognition is simple and is suited to parallel processing, it has the drawback that it is sensitive to deviation of the input waveform to the inverse filter (i.e., the speech waveform). From such a viewpoint, this paper introduces the polarized linear predictive error coding method, which is a recognition scheme, in which it is assumed that deviation in the speech waveform is due to change in the pole of the transfer function of the filter for speech generation (called vocal tract filter) and, by improving the residual waveform power method, the sensitivity to the change of poles is decreased. The POLPEC method has the effect of decreasing the residual power by subtracting from the residual waveform sequence the component which is due to the deviation of poles. It is verified by experiment using synthetic speech that this reduces the sensitivity to the predetermined deviation of poles.