Significance of Phase in Speech Analysis

The phase of speech signals plays signi cant role in human perception of speech\ud sounds and speaker identity. Yet, it received lesser prominence than magnitude in\ud mainstream speech signal processing, due to the di�culties associated with its com-\ud putation and processing. The computation of phase of Fourier transform (phase\ud spectrum) and analytic signal obtained using Hilbert transform (analytic phase) are\ud a ected by the phase wrapping problem. Very few methods exist for e ective compu-\ud tation of phase, like group delay and instantaneous frequency, which are the deriva-\ud tives of phase spectrum and analytic phase, respectively. But, these representations\ud of phase are also impaired by several spurious e ects caused by spectral zeros, lower\ud signal amplitudes, glottal excitation particulars, etc. of speech signals