Singing Robots: How Embodiment Affects Emotional Responses to Non-Linguistic Utterances

Robots are often envisaged as embodied agents that might be able to intelligently and expressively communicate with humans. This could be due to their physical embodiment, their animated nature, or to other factors, such as cultural associations. In this study, we investigated emotional responses of humans to affective non-linguistic utterances produced by an embodied agent, with special attention to the way that these responses depended on the nature of the embodiment and the extent to which the robot actively moved in proximity to the human. To this end, we developed a new singing robot platform, ROVER, that could interact with humans in its surroundings. We used affective sound design methods to endow ROVER with the ability to communicate through song, via musical, non-linguistic utterances that could, as we demonstrate, evoke emotional responses in humans. We indeed found that the embodiment of the computational agent had an affect on emotional responses. However, contrary to our expectations, we found singing computers to be more emotionally arousing than singing robots. Whether the robot moved or not did not affect arousal. The results may have implications for the design of affective non-speech audio displays for human-computer or human-robot interaction.