MRI study of coarticulation in European Portuguese

Abstract

For this study, a small part of a recently acquired MRI database for European Portuguese (EP) was used. The sounds studied were the 12 EP voiced and unvoiced fricatives and stop consonants, produced in a symmetric VCV context. The vowels chosen were the cardinal vowels [i, a, u]. The speaker sustained the fricative sounds and maintained stop articulation during the 5.6 s of the acquisition time (T1 TSE sequence). The contours were obtained using the seeded region growing method. The influence of the seed placement was evaluated through the generation of 100 contours, with random seeds, for each sound. It was possible to verify, for the EP, some facts already reported by other authors relative to coarticulation in other languages. In general, EP stops are less resistant to coarticulatory effects than fricatives. The EP sounds presenting the highest resistance to coarticulation are the unvoiced postalveolar fricative [∫] and corresponding voiced fricative. As an example of other relevant results, for stops [t], [d] and fricative [s] there is no significant effect of the vowel in the region tongue blade region, being the influence evident in the production of the stops [k] and [g]. [Work supported by FCT, Portuguese Research Agency, by Project HERON POSC/PLP/57680/2004.]