Determination of Vocal Tract Shape from Acoustical Measurements
B. Gopinath, M. M. Sondhi · The Journal of the Acoustical Society of America · 1969
A direct noniterative method is described for determining the shape of the vocal tract from a specification of the acoustical driving point impedance at the lips. One way of specifying the impedance at the lips is to specify the volume velocity at the lips (as a function of time) due to an impulse of pressure. If this “impulse response” can be accurately determined, the length of the tube and the glottal boundary condition need not be known. Another way is to specify all the poles and residues (or poles and zeros) of the impedance. As is well known [see, for example, M. R. Schroeder, J. Acoust. Soc. Amer. 41, 1002 (1967) and P. Mermelstein, J. Acoust. Soc. Amer. 41, 1283 (1967)], either of these specifications gives a unique shape. In cases where only a finite number of poles and residues can be measured, rationales are presented for specifying the remaining ones.