Recently, methods for adding emotion to synthetic speech have received considerable attention in the field of speech synthesis research. For generating emotional synthetic speech, it is necessary to control the prosodic features of the utterances. The authors propose a case-based method for generating emotional synthetic speech by exploiting the characteristics of the maximum amplitude and the utterance time of vowels, and the fundamental frequency of emotional speech. As an initial investigation, they adopted the utterance of Japanese names, which are semantically neutral. By using the proposed method, emotional synthetic speech made from the emotional speech of one male subject was discriminable with a mean accuracy of 70% when ten subjects listened to the emotional synthetic utterances of “angry,” “happy,” “neutral,” “sad,” or “surprised” when the utterance was the Japanese name “Taro.”
Interpretation of User Evaluation for Emotional Speech Synthesis System
