Augmenting a group of task-driven robotic arms with emotional musical prosody

Emotional Musical Prosody (EMP) uses emotion-tagged musical phrases as a form of communication. Past research has shown EMP is effective at improving trust, likeability, and perceived intelligence of individual robotic arms. In this paper, we address further use cases for EMP, in particular the role it can play in emotional contagion for a large group of 10 robots and a human participant. We created two studies, the first of which was conducted online with 111 participants and aimed to replicate past studies while analyzing whether participants believed emotional contagion could take place, and how ratings for contagion correlated with ratings for trust, warmth, competence, and discomfort. The second study was done in person with 20 participants and aimed to understand how EMP altered the perception of the robots. In the interviews we found multiple areas of interest emerge through a constant comparison analysis. These themes split into three categories, firstly, perception of robot emotion, musical reactions, and gesture, which focused on manners in which EMP shaped participant responses. The second category, robotic groups, featured responses specific to groups of robots. The third category HRI metrics refers to comments from participants that relate to common HRI studies. Our findings suggest broad potential use cases for sound and music in human-robot communication.