[Show abstract][Hide abstract] ABSTRACT: A novel technique to implement and control an acoustic tube model
of the human vocal tract is introduced. This model is an extension to
the traditional Kelly-Lochbaum model, since not only the diameter of
individual uniform tube sections but also their length, i.e., the
positions of scattering junctions, can be continuously varied. The vocal
tract model is implemented by means of FIR-type interpolation and
deinterpolation that are used to locate the junctions. The authors show
that in this kind of model the articulators can be presented in a
natural manner enabling easy control of the model from articulatory data
Speech, Image Processing and Neural Networks, 1994. Proceedings, ISSIPNN '94., 1994 International Symposium on; 05/1994
[Show abstract][Hide abstract] ABSTRACT: An extension to the traditional Kelly-Lochbaum (1962) vocal tract model is introduced. In the new model not only the diameter but also the length of each tube section can be continuously adjusted. This is achieved by using fractional delay filter techniques such as interpolation and deinterpolation. The filter structure consisting of bidirectional delay lines (digital waveguides) and interpolated ports that connect two or more waveguide sections together is called a fractional delay waveguide filter (FDWF). The interpolated version of the two-port scattering junction is presented and a technique for analyzing the degradation due to approximation errors in interpolation and deinterpolation is described. It is shown that when an FDWF structure with Lagrange interpolation is used a vocal tract model needs to be implemented using oversampling. For example, a sampling rate of 22 kHz is adequate for producing high-quality synthetic sounds at a 5 kHz bandwidth.
Proceedings - ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing 04/1994; 1:585-588.