Modeling of the tongue using a quadratic curve
K. Hashimoto, Masumi Tanimoto · The Journal of the Acoustical Society of America · 1978
An analytic procedure in which a quadratic curve (QC) is used as a reference was applied to the description of the shape of the tongue during speech. By free fitting the QC to each frame of the tongue profile, the loci of the vertices and the centers of curvature were traced. The distributions of the eccentricities and the curvature radii at the vertices are almost Gaussian and their means are 0.85 and 2.5 mm, respectively, while the respective standard deviations are 0.08 and 0.5 mm. Aspects of the deviations from the average QC seen typically around the tongue tip at the articulation of the alveolars are characterized by using the principal components of the deviations. Finally, multiple regression analyses are applied to determine the relations of the QC parameters to the results of the acoustical analyses and also their relations to other models.