Hearing a Nose? User Expectations of Robot Appearance Induced by Different Robot Voices

Congruence between the visual appearance of a robot and its behavioral and communicative characteristics has been shown to be a crucial determinant of user acceptance. Given the growing popularity of speech interfaces, a coherent design of a robot's looks and its voice is becoming more important. Which robot voice fits which appearance, however, has hardly been investigated to date. This is where the present research comes in. A randomized lab experiment was conducted, in which 165 participants listened to one of five more or less humanlike robot voices and subsequently drew a sketch corresponding to their imagination of the robot. The sketches were analyzed regarding the presence of various body features. While some features appeared in almost all drawings regardless of the condition (e.g., head, eyes), other features were significantly more prevalent in voice conditions characterized by low human-likeness (wheels) or high human-likeness (e.g., nose). Our results give first hints on which embodiment users might expect from different robotic voices.