Measuring The Shape Of The Vocal Tract: An Application Of MRI

Magnetic Resonance Imaging (MRI) techniques can be used to obtain basic dimensional data on vocal tract shapes, areas and volumes that are needed for the development of computational models of speech articulation and for aeroacoustic studies of sound production in the vocal tract. Sequences of MR images of tract shapes have been obtained from two subjects in the axial, coronal and sagittal planes while they produced sustained vowels. Three-dimensional (3-D) measurements of the tract shapes responsible for the vowel sounds of these subjects have been made by computer and then used to synthesize artificial vowels. A comparison of the acoustic features of the artificial vowels with the subjects´ natural vowel productions provides an opportunity to test the accuracy of the 3-D measurements and/or acoustic theory.