Description of Tongue and Lip Movement in a Jaw-Based Coordinate System
Paul G. Mermelstein, Shinji Maeda, Osamu Fujimura · The Journal of the Acoustical Society of America · 1971
The midsagittal projection of the upper tongue surface is described with reference to a jaw-based coordinate system which rotates with the mandible about a point fixed with respect to the maxilla. A jaw based coordinate system is also useful in describing the articulatory conditions of the lips. For vowels, specification of the maximal elevation point of the tongue hump is used to construct curves which approximate the tongue outline. Addition of one lip-rounding parameter allows specification of the orifice dimensions and the extent of protrusion. Subsequent consideration of the jaw angle allows computation of the midsagittal cross dimension of the vocal tract. For consonants, additional separate parameters are introduced for specification of labial, dental, and palatal constrictions.