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

The process of generating the F-0 contour of speech has been modeled quite accurately in mathematical terms by Fujisaki and his coworkers, but the extraction of parameters of the underlying commands from an observed F-0 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 F-0 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.