Hyperbolic structure of fundamental frequency contour

In this paper, we propose an approach to transformation of fundamental frequency (F0) contours for conversational speech synthesis. The figure of F0 in relations to the period of cycles of sound waves is one branch of the rectangular hyperbola. Based on a few symmetry assumptions on the hyperbolic property, we achieve a generalized hyperbolic structure so as to aggressively manipulate F0 contours. The modeling proves an equivalent expression of the resonance mechanism capable for dealing with the interaction of tone and intonation. Also, it is language-independent because no language-dependent hypothesis is necessary. This paper describes two applications of the hyperbolic structures of F0 contours to prosodic information processing. One modulates the baseline F0 contours when fusing additional makeup information onto them without altering the underlying linguistic information. The other separates local rise/fall F0 movements and global scale component from observed F0 contours, both being useful for estimating dynamical F0 variation. Our experimental results are very positive.