Evolving Emotional Prosody.pdfVIP

Evolving Emotional Prosody Cecilia Ovesdotter Alm and Xavier Llora? IlliGAL Report No. 2006018 April, 2006 Illinois Genetic Algorithms Laboratory University of Illinois at Urbana-Champaign 117 Transportation Building 104 S. Mathews Avenue Urbana, IL 61801 Office: (217) 333-2346 Fax: (217) 244-5705 Evolving Emotional Prosody Cecilia Ovesdotter Alm Xavier Llora? Department of Linguistics National Center for Supercomputing Applications, University of Illinois at Urbana-Champaign University of Illinois at Urbana-Champaign, 707 S. Mathews Ave., Urbana, IL 61801, USA 1205 W. Clark Street, Urbana, IL 61801, USA ebbaalm@ xllora@ Abstract Emotion is expressed by prosodic cues, and this study uses the active interactive Genetic Al- gorithm to search a wide space for sad and angry parameters of intensity, F0, and duration in perceptual resynthesis experiments with users. This method avoids large recorded databases and is flexible for exploring prosodic emotion parameters. Solutions from multiple runs are analyzed graphically and statistically. Average results indicate parameter evolution by emo- tion, and appear best for sad speech. Solutions are quite successfully classified by CART, with duration as main predictor. 1 Introduction Emotion is expressed by prosodic cues, but their interplay is an open question, which is compli- cated by a challenging search space. Common procedure for emotional speech research depends on recording and analyzing large databases. Instead, this work uses the active interactive Genetic Algotihm (aiGA) (Llora?, Al??as, Formiga, Sastry, Goldberg, 2005) to evolve emotional prosody in perceptual resynthesis experiments. Within this framework, fundamental parameters of emotional prosody become an optimization problem, approximated by searching perceptual space of a listener via interactive feedback. In contrast to unit or parameter estimation based on emotional speech databases, e.g. (Hofer Clark, 2005; Hsia, Wu, Liu, 2005), the method only requires