A novel algorithm of seeking FrFT order for speech processing

The determination of the optimal fractional Fourier transform (FrFT) order is a crucial issue for FrFT. This paper introduces a novel algorithm is proposed for the estimation of FrFT order. We use the information of pitches, harmonies and formants in the correlogram of Gammatone filterbanks to get a few candidates of the transform order. The proposed method reduces the computation complexity in the searching of optimal transform order. We apply this method for speech processing such as Mel-frequency cepstral coefficients (MFCC) extraction and speech enhancement. The experiment of MFCC extraction shows that the proposed method is superior to the traditional method based on Fourier Transform in the sense of Fisher distance improvement. The experimental results of speech enhancement also show the improvement in sense of SNR and the Itakura-Saito distance of LPC coefficients.