On the Derivation of Area Functions and Acoustic Spectra from Cinéradiographic Films of Speech

The objective of this paper is to determine whether it is possible to derive a transformation, valid for a given talker, for determining area functions corresponding to any speechlike articulatory configuration from measurements on lateral cineradiographic films of the vocal mechanism. A tentative set of rules for accomplishing this transformation has been established. The rules are specified largely in terms of a series of functions that relate the cross‐sectional area at each of a number of points along the vocal tract to linear dimensions determined from the x‐ray films and incorporate the effects of jaw and velum positions. The validity of area functions derived through use of these rules has been tested by comparing formant frequencies measured for the corresponding utterances with those calculated (by digital computer) from the area functions. Webster's horn equation is taken as the basis for calculating formant frequencies from area functions. The corresponding spectra are also computed for compari...