Lingual differences in Brazilian Portuguese oral and nasal vowels: An MRI study

It has been shown that oral and nasal vowel pairs can differ substantially in their oro-pharyngeal configuration (besides the position of the velum), an effect that may lead to the enhancement of certain acoustic features associated with nasalization. We use real-time MRI to compare the lingual configuration of oral and nasal vowels in Brazilian Portuguese at various timepoints during the production of these vowels. Results of area function comparisons and smoothing spline ANOVAs indicate that lingual articulation of nasal vowels increasingly moves towards the center of the oral cavity throughout the duration of the vowel, whereas the lingual articulation of their oral counterparts moves towards the outer extrema. We conclude that the lingual configurations in these targets are in line with the effects of vowel nasalization on formant frequencies. This further reaffirms the possibility that oral articulation in nasal vowels may be employed to enhance the acoustic effects of nasalization.