Linear prediction phase spectrum for formant extraction

Extraction formant information from linear prediction phase spectrum is proposed. It is shown that the derivative of phase spectrum gives reliable formant information. Since the phase spectra of several resonators in cascade are additive and also since the resonance peaks are sharper in the derivative of the phase spectrum than in the magnitude spectrum, the problem of identifying merged peaks is very easily solved by this method. Application of the method is illustrated through examples of linear prediction spectra obtained for simulated and actual speech segments.