Article,
MRI study of coarticulation in European Portuguese
Journal of the Acoustical Society of America, (2007)
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 (integral) 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.
