Vocal tract dimensions obtained from magnetic resonance images
Thomas E. Baer, John C. Gore, L. Carol Gracco, Patrick W. Nye · The Journal of the Acoustical Society of America · 1988
Serial magnetic resonance images (MRIs) of the vocal tract were obtained from two speakers of English during steady-state productions of nine isolated vowels including the four point vowels. Vowels were sustained for about 2.5 min, interrupted only by inhalations. Maintenance of a stable configuration was aided by a head positioner and by constantly hearing the target vowel. Images were obtained in the transaxial, and also in the sagittal and coronal planes for the four point vowels. Images representing 0.5- to 0.8-cm slice thickness were obtained at 0.5-cm intervals. Computer-assisted tracings of the boundaries of the vocal tract were used to construct a three-dimensional digital model of the airway. Using methods from the Haskins articulatory synthesizer, vocal-tract area functions were derived and vowels were resynthesized. Analysis of the first three formants showed good agreement with the subjects' original productions. Data on the relationship between the sagittal dimensions and the cross-sectional areas at various positions in the vocal tract were also obtained and will be reported. [Work supported by NIH, the Klingstein Fund, General Electric Co., and the Yale School of Medicine.]