Deterministic characteristics of LPC distances: An inconsistency with perceptual evidence

Deterministic characteristics of LPC distances are discussed in this paper. The study is carried out especially for French vowels which have clearly formant structure. Two studies are realized here: the first one is a study of contributions of different parameters (formants in particular) with help of sensibility functions and speech like spectra; the second one is an analysis of distance matrices by a multidimensional scaling method. Our goal is to examine the consistency of LPC distance measures with the formants perception, which are the most significant phonetic correlates of vowels. The results show some unsuitable properties of classic distances and we propose to evaluate distances on a phonetic plane.