Articulatory copy synthesis using a nine-parameter vocal tract model

The parameters of a nine-parameter vocal tract model, in conjunction with a time-domain articulatory synthesiser, have been optimised to fit, for nine English vowels, the measured vocal tract shapes and the first three formant frequencies for a particular speaker. Techniques have also been developed for interpolating each of the parameters among these nine vowel points in the f1,f2 plane. The method effectively defines a two-dimensional subspace of the parameter space, which is accessed by f1 and f2. Segments of speech consisting of vowels or vowel-vowel diphones may then be synthesised using formant tracks to determine the selection of the parameters of the model. Parameter values for selected consonants have also been obtained, based on magnetic resonance images. A three-formant interpolation technique allows transitions for the corresponding VC and CV diphones to be copied from natural speech.