Verification of Acoustical Correlates of Emotional Speech using Formant-Synthesis

This paper explores the perceptual relevance of acoustical correlates of emotional speech by means of speech synthesis. Besides, the research aims at the development of »emotionrules« which enable an optimized speech synthesis system to generate emotional speech. Two investigations using this synthesizer are described: 1) the systematic variation of selected acoustical features to gain a preliminary impression regarding the importance of certain acoustical features for emotional expression, and 2) the specific manipulation of a stimulus spoken under emotionally neutral condition to investigate further the effect of certain features and the overall ability of the synthesizer to generate recognizable emotional expression. It is shown that this approach is indeed capable of generating emotional speech that is recognized almost as well as utterances realized by actors.