ICP, INPG & Univ. Stendhal, 46 Ave. Felix Viallet, 38031 Grenoble Cedex, France
This paper presents an approach to vowel normalization based on the exloitation of the concept of formant to cavity affiliation as described in the vocalic theory of speech production [G. Fant, Acoustic Theory of Speech Production (Mouton, La Hague, 1960)]. For closed vowels, this concept allows an estimation of the ratio of the respective back and front cavities lengths of two speakers, by the ratio of the associated formants. In order to propose a normalization of the vocalic space of different speakers, a ``reference speaker'' was used whose articulatory and acoustic properties are well defined: the articulatory model as proposed by Maeda [J. Acoust. Soc. Am. Suppl. 1 81, S146 (1988)]. Vowel normalization consists then in the projection of the vocalic space of one given speaker in the vocalic space of this model. Geometrical relations between the studied speaker and the ``reference speaker'' are extracted from [i] and [u] for front and velopalatal vowels, and from [a] and [u] for back and velopharyngeal vowels. Here, [y] and [u] give some indications about the lip shapes. This method is here tested by her ability to predict the vowels of the studied speaker starting from the vowels of this model.