hide
Free keywords:
Nasal vowels, real-time MRI, image processing, quantitative methods
Abstract:
The characterisation of nasal vowels is not only a question ofstudying velar aperture. Recent work shows that oropharyngeal
articulatory adjustments enhance the acoustics of nasal couplingor, at least, magnify differences between oral/nasal vowel congeners. Despite preliminary studies on the oral configurations of nasal vowels, for European Portuguese, a quantitative analysis is missing, particularly one to be applied systematically to a desirably large number of speakers. The main objective ofthis study is to adapt and extend previous methodological advances for the analysis of MRI data to further investigate: howvelar changes affect oral configurations; the changes to the articulators and constrictions when compared with oral counteparts; and the closest oral counterpart. High framerate RT-MRIimages (50fps) are automatically processed to extract the vocal tract contours and the position/configuration for the different articulators. These data are processed by evolving a quantitative
articulatory analysis framework, previously proposed by the authors, extended to include information regarding constrictions
(degree and place) and nasal port. For this study, while the analysis of data for more speakers is ongoing, we considered a set
of two EP native speakers and addressed the study of oral and nasal vowels mainly in the context of stop consonants.
