Speech signal analysis and synthesis via Fourier-Bessel representation

This paper concerns with the Fourier-Bessel (FB) representation of speech signal and its application in speech analysis and synthesis. The Fourier-Bessel representation of the speech signal is obtained using Bessel function as a basis set. This is accomplished by determining the Fourier-Bessel series expansion coefficients Cmof the short-time speech signal at successive instants of time. The successive sets of coefficients are then displayed in time-index-coefficient (t-m-Cm) plot. The patterns on the plot yield discriminating feature for the spoken words and may be used as speech feature for speech recognition. Unlike the spectrogram which represents the spectral magnitude content of the signal, the (t-m-Cm) plot is the complete characterization of the time-domain signal. It is demonstrated that good quality intelligible speech signal can be reconstructed using only a small portion of information contained in the (t-m-Cm) plots. Examples showing discriminating (t-m-CM) plots and reconstructed speech using only a small portion of information in the plot are given for vowel, stop, fricative and affricate.