1. A speech processing method for deciding emphasized portion based on a set of speech parameters for each frame, comprising the steps of: (a) obtaining an emphasized-state appearance probability for a speech parameter vector, which is a quantized set of speech parameters for a current frame by using a codebook which stores, for each code, a speech parameter vector and an emphasized-state appearance probability, each of said speech parameter vectors including at least one of a fundamental frequency, power and temporal variation of dynamic-measure and/or an inter-frame difference in at least one of those parameters; (b) calculating an emphasized-state likelihood based on said emphasized-state appearance probability; and (c) deciding whether a portion including said current frame is emphasized or not based on said calculated emphasized-state likelihood.