Fast formant estimation by complex analysis of LPC coefficients

This paper describes a selective root finding method based in residue theory. It can find the poles of the LPC model of the speech signal close to the unit circle, without spend computations with the lesser significant internal poles. This feature makes it faster than generic root-finding methods, if the founded poles complain certain specifications. With a high order LPC model, the selected poles are in better correspondence with the formants than the local maxima of the spectral envelope. Experimental results are showed.