Sound Production for the Emotional Expression of Socially Interactive Robots

Abstract

In conclusion, the paper presents three processes of sound production needed to enable emotional expression in robots. First, we consider the relation between three basic emotions of happiness, sadness, and fear, and eight musical parameters of mode, tempo, pitch, rhythm, harmony, melody, volume, and timbre. The survey using the 5-point Likert scale, which was administered to 20 participants, proved the validity of Silbot's emotional sound. In addition, the synchronizing of the robot's basic emotional sounds of happiness, sadness, and fear with facial expressions is tested through the experiment. The results support the hypothesis that the simultaneous presentation of sound samples and facial expressions is more effective than the presentation of either sound or facial expression. Second, we produced emotional sounds for joy, shyness, and irritation in order to determine the intensity variation of the robot's emotional state. Owing to the technical limitations of the computer systems controlling the robot, only three musical parameters of volume, tempo, and pitch are regulated for intensity variation. Third, the synchronization of the durations of