Speech synthesis by mapping articulator movement patterns to a shape-based area function model of the vocal tract

Abstract

Orthogonal components of tongue and lip displacement data from two speakers in the Univ. of Wisconsin x-ray microbeam database (Westbury, UW–Madison, 1994) were determined with a principal components analysis (PCA). The PCA was performed on steady-state vowels and at the sentence level. For every time frame, the analysis consisted of fitting a cubic spline to four pellet points on the tongue and to modified positions for the incisor pellet and the upper and lower lip pellets. The modifications brought the pellet positions to the level of the airway. The PCA was performed over a collection of frames and showed that the first two (most significant in terms of variance) orthogonal components were similar in shape to those determined from a set of MRI-based vocal tract area functions [Story and Titze, J. Phonetics 26, 223–260 (1998)]. Next, the coefficients determined from a sentence-level PCA of the microbeam data were normalized and used as input to an area function model based also on orthogonal shaping components. The result is that articulatory movement patterns from data in the x-ray microbeam database can be transformed to movement patterns of a vocal tract area function to reproduce (synthesize) the original sentence. [Work supported by NIH R01-DC04789-01.]