Hegde, R. M., Murthy, H. A., & Gadde, V. R. R. (2006). Significance of joint features derived from the modified group delay function in speech processing. EURASIP Journal on Audio, Speech, and Music Processing, 2007, 1-13.
This paper investigates the significance of combining cepstral features derived from the modified group delay function and from the short-time spectral magnitude like the MFCC. The conventional group delay function fails to capture the resonant structure and the dynamic range of the speech spectrum primarily due to pitch periodicity effects. The group delay function is modified to suppress these spikes and to restore the dynamic range of the speech spectrum. Cepstral features are derived from the modified group delay function, which are called the modified group delay feature (MODGDF). The complementarity and robustness of the MODGDF when compared to the MFCC are also analyzed using spectral reconstruction techniques. […]