ASA 124th Meeting New Orleans 1992 October

3pSP5. Visualization of 3-D palate shape for an enhanced electropalatography system.

W. S. C. Chiu

Christine H. Shadle

Dept. of Electron. and Comput. Sci., Univ. of Southampton, Southampton SO9 5NH, England

Electropalatography (EPG), a system for real-time measurement of tongue--palate contact during speech, uses a stylized 2-D output system which, though useful for speech therapy and research, omits the actual spatial location of the contacts. This paper presents an enhanced EPG (eEPG) system that combines standard EPG data and digitized palate shape data to display the tongue--palate contact pattern in 3D. The palate shape can be obtained using a color-encoded structured light 3-D digitization system [Monks et al., IEEE Coll. on Biomed. Apps. of Dig. Sig. Proc. Dig. No. 1989/144, London (1989)]. The 3-D palate shape is represented by a series of polygons and can be displayed on a graphics workstation as a smoothly shaded, ``lit,'' colored surface, on which colored EPG contact patterns can be superimposed. Contact patterns can then be related more easily to articulatory features, and parameters derived from the contact pattern can be expressed in terms of absolute distances, making them more useful for sound production models. Examples of cross-subject comparisons will be shown, including cases where the dimensions of the constriction for an /s/ appear identical in EPG but clearly differ with eEPG. [Work supported in part by a Croucher Foundation Scholarship and SERC Grant No. GR/G 2115.]