Do Isolated Vowels Represent Vowel Targets in French? An Acoustic Study On Coarticulation

Abstract

Coarticulatory effects of labial, dental, palato-velar and uvular places of articulation on vowel targets of ten French oral vowels /i, e, ɛ, a, u, o, ɔ, y, ø, œ/ were examined. The average vowel formant frequencies F1, F2, F3 and F4 in symmetrical sequences CVCVCVC to formant values of the same vowels in isolation were compared. The results show that the direction and magnitude of coarticulation of most vowels follow, as expected, contextual assimilation or acoustic centralization. Nevertheless, vowels /a/ and /ɔ/ present unpredictable coarticulatory patterns. This can be explained by the fact that 1) /a/ has two phonetic variants depending on the environment: back vowel [ɑ] in isolation and central/front vowel [a] in continuous speech, and 2) uttering [ɔ] in isolation violates the phonotactic rules of standard French.These results suggest that coarticulatory effects on vowels /a/ and /ɔ/ are probably not to be studied from their isolated positions.