This paper deals with determination of a penalty matrix that should represent differences between various communicative functions. These are supposed to describe expressivity that can occur in expressive speech and were designed to fit a limited domain of conversations between seniors and a computer on a given topic. The penalty matrix is assumed to increase a rate of the expressivity perception in synthetic speech produced by unit selection method. It should reflect both acoustic differences and differences based on human perception of expressivity.

Index Terms: expressive speech synthesis, unit selection, target costs, communicative functions