ASA 130th Meeting - St. Louis, MO - 1995 Nov 27 .. Dec 01

3aSC1. Vocal tract shapes and area functions from magnetic resonance imaging (MRI).

Brad H. Story

Ingo R. Titze

Eric A. Hoffman

Univ. of Iowa, Iowa City, IA 52242

There have been considerable research efforts in acoustic modeling of speech but there is still only a small body of information regarding direct three- dimensional measurements of the vocal tract shape. The purpose of this study was to acquire, using MRI, an inventory of three-dimensional vocal tract airway shapes that correspond to a particular set of vowels and consonants. The MR imaging was carried out for one subject (29-yr-old male, native of the midwestern United States) using a GE Signa 1.5-T scanner. The images were reconstructed and analyzed with a general display and quantitation package. The resulting three-dimensional (3D) vocal tract shapes were analyzed to find the cross-sectional areas perpendicular to the centerline extending from the glottis to the mouth to produce an ``area function.'' These area functions were then used as input to a wave-reflection type model of one-dimensional acoustic-wave propagation in the vocal tract. 3D reconstructions and area functions of the vocal tract shapes will be shown and the corresponding simulations of the speech sounds will be demonstrated.