Multi-frame approach for parameter estimation of a physiological model of speech production

The authors address the problem of how to accommodate varying speaker characteristics by selecting appropriate control parameters for a vocal tract/vocal cord model. This problem is basic to speech coding based on articulatory modeling. Experience shows that, for example, nominal vocal-tract length of the speaker, speech amplitude scale factor, as well as some glottal characteristics, cannot be accurately estimated on a frame-by-frame basis. The solution to this problem is found by a search procedure employing several frames of speech for estimating global speaker characteristics, in the form of scaling parameters, which is separate from the local (frame-to-frame) optimization of other parameters