A method for automatic extraction of model parameters from fundamental frequency contours of speech

The process of generating the F0 contour of speech has been modeled quite accurately in mathematical tenns by Fujisaki and his coworkers, but the extraction of parameters of the underlying commands from an observed F0 contour is an inverse problem that can be solved only by successive approximation. In order to guarantee an efficient and accurate search for the solution, one needs to start with a set of initial values that are close enough to the optimum. This paper presents a method for pre-processing a measured F0 contour to obtain its approximation consisting of third-order polynomial segments that are continuous and differentiable everywhere. It is shown that the proposed method allows one to obtain first-order approximations to the parameters of accent commands for about 90% of all the accent commands, and of phrase commands for about 84% of all the phrase commands.