SPEECH SYNTHESIS APPARATUS AND SELECTION METHOD

A speech synthesizer includes plural synthesis engines each having different characteristics and converting text-form utterances into speech form. One of the synthesis engines is selected as the current operative engine for producing speech-form utterances for a speech application. If the overall quality of the speech-form utterance produced by the text-to-speech converter of the current operative synthesis engine becomes inadequate, a different engine is selected as the current operative synthesis engine.