14th International Congress of Phonetic Sciences (ICPhS-14)

San Francisco, CA, USA
August 1-7, 1999

Phase Spaces of Vowel Systems - A Typology in the Light of the Dispersion-Focalization Theory (DFT)

Nathalie Vallée, Jean-Luc Schwartz, Pierre Escudier

Institut de la Communication Parlée INPG/Université Stendhal, Grenoble, France

The Dispersion-Focalization Theory (DFT) is a predictive model of vowel systems based on the minimization of two combined costs, one aiming at increasing auditory distances between vowel spectra (“dispersion”), the other aiming at increasing the perceptual salience of each spectrum through formant proximities (“focalization”). This model is controlled by two parameters: A, the weight of F, with regards to the group of higher formants F, F, F, and a the weight of focalization (encouraging “focal vowels”) with regards to dispersion. For a given number of vowels we can predict in the (A, ol)space what should be the preferred system, together with other sub-optimal ones. This is achieved thanks to the so-called “phase space”, a well-known procedure in thermodynamics used to predict the state of a given substance as a function of pressure and temperature. The present work consists in determining how many phonological vowel systems within the 451 UPSID languages agree with different possible structures predicted by the DFT. We present a complete typology of systems with 3 to 7 vowel qualities in the light of the DFT, we introduce a new variant inspired from physics - that is, polymorphism within a given phase, leading to define superstructures in vowel systems - and we show that the phase space methodology allows to predict a great part of the observed systems. This enables to better specify the A value: a value around 0.2 seems more or less compatible with about 85% of the 3-to-7 vowels systems considered in the UPSID basis.

Full Paper

Bibliographic reference.  Vallée, Nathalie / Schwartz, Jean-Luc / Escudier, Pierre (1999): "Phase spaces of vowel systems - a typology in the light of the dispersion-focalization theory (DFT)", In ICPhS-14, 333-336.