“…To be effective social interaction partners, robots must also exploit several channels (i.e., auditory, visual) and mechanisms (e.g., body posture, facial expressions, vocal prosody, touch, gaze) to communicate their internal emotional states and intentions in an authentic and clear way [10,11]. Many researchers, explore the design space of anthropomorphic or zoomorphic robots equipped with expressive faces (e.g., [5,[12][13][14][15][16]), emotional voices (see [17] for a survey), body language (e.g., [18][19][20][21]), and other features and capacities to make human-robot social interactions more human-like. While initially, Human-Robot Interaction (HRI) research on the emotional expressions of robots had largely focused on single modalities in isolation [22], more recently, researchers have begun to integrate multiple channels, in order to approach the richness of human emotional communication.…”