Dispersion and variability of Catalan vowels

Formant frequency data for Catalan vowels reveal essentially the same degree of expansion for three dialect systems with seven vowels (Valencian, Eastern Catalan, Western Catalan). A slightly larger vowel space dispersion for a fourth system with those same vowels and stressed /c/ (Majorcan) is not clearly associated with a larger vowel system size but rather with a local effect of schwa in repelling neighbouring vowels or with specific requirements on the production of some peripheral vowels. Schwa appears to be targetless or specified for a widely defined mid central target. Intervocalic distances were found to vary according to dialect and to vowel pair, and to compensate with each other such that the maximal formant frequency range between point vowels is kept constant across dialects. These findings are partially in support of the Adaptive Dispersion Theory, i.e., they are in agreement with the claim that vowel system expansion should be proportional to vowel system size but not with the notion that adjacent vowels should be evenly spaced in identical vowel systems. Patterns of vowel variability differ depending on the contextual or non-contextual factors involved, i.e., F1 shows more contextual and token-to-token variation for open vs. close vowels, while F2 exhibits little contextual variation and much token-dependent variation for /i/ and the opposite trend for /u/ and /c/. These patterns are accounted for assuming that random variability for vowels is ruled by the precision involved in achieving a specific articulatory target, and that contextual variability is determined by the vowel articulatory requirements and by the relative compatibility between the articulatory gestures for adjacent vowels and consonants. 2005 Elsevier B.V. All rights reserved.