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Gammachirp Filter, Wavelet Packet, MFCC, Impulsive Noise.

Modern automatic speech recognition (ASR) systems typically use a bank of linear filters as the first step in performing frequency analysis of speech. On the other hand, the cochlea, which is responsible for frequency analysis in the human auditory system, is known to have a compressive non-linear frequency response which depends on input stimulus level. It will be shown in this paper that it presents a new method on the use of the gammachirp auditory filter based on a continuous wavelet analysis. The essential characteristic of this model is that it proposes an analysis by wavelet packet transformation on the frequency bands that come closer the critical bands of the ear that differs from the existing model based on an analysis by a short term Fourier transformation (STFT). The prosodic features such as pitch, formant frequency, jitter and shimmer are extracted from the fundamental frequency contour and added to baseline spectral features, specifically, Mel Frequency Cepstral Coefficients (MFCC) for human speech, Gammachirp Filterbank Cepstral Coefficient (GFCC) and Gammachirp Wavelet Frequency Cepstral Coefficient (GWFCC). The results show that the gammachirp wavelet gives results that are comparable to ones obtained by MFCC and GFCC. Experimental results show the best performance of this architecture. This paper implements the GW and examines its application to a specific example of speech. Implications for noise robust speech analysis are also discussed within AURORA databases.