Patent ID: 7349847

Claim:
A speech synthesis apparatus for synthesizing speech using speech elements so as to transform a voice characteristic of the speech, said speech synthesis apparatus comprising: an element storing unit operable to store speech elements; a function storing unit operable to store transformation functions for respectively transforming voice characteristics of the speech elements; a voice characteristic designating unit operable to receive a voice characteristic designated by a user; a prosody generating unit operable to obtain text data, estimate a prosody from a phoneme included in the text data, and generate prosody information which indicates the phoneme and the prosody; a similarity deriving unit operable to derive a degree of similarity by comparing an acoustic characteristic of one of the speech elements stored in said element storing unit with an acoustic characteristic of a speech element which is used for generating one of the transformation functions stored in said function storing unit and which is specific to the transformation function; a selecting unit operable to select, from said element storing unit, a speech element corresponding to the phoneme and the prosody indicated in the prosody information, and select, from said function storing unit, a transformation function for transforming a voice characteristic of the selected speech element into the voice characteristic received by said voice characteristic designation unit, based on the degree of similarity derived for the selected speech element by said similarity deriving unit and the voice characteristic received by said voice characteristic designation unit; and a transforming unit operable to apply the transformation function selected by said selecting unit to the selected speech element, and to transform the voice characteristic of the selected speech element into the voice characteristic received by said voice characteristic designation unit.