Auditory and Other Non-verbal Expressions of Affect for Robots

This work focuses on the use of non-verbal methods of communicating affect in non-anthropomorphic appearance-constrained robots. The concepts discussed can be applied to other types of robotic systems. The paper gives a survey of relevant literature from the psychology community. Non-verbal methods of affective expression cannot be the sole means of communicating affect in robotic systems; however it can be appropriate as part of a multi-modal affective system. Another important factor is the distance between the robot and human with which it is interacting. From the psychology literature, there are four main zones of social interaction: intimate (contact – 0.46 m), personal (0.46 – 1.22 m), social (1.22 – 3.66), and public (3.66 and beyond). Sounds, tones, and/or music are appropriate to use in the intimate and personal zones; however it is not likely to be appropriate in the social and public zones due to environmental background noise. Communications are often challenging in search and rescue applications. Injuries that can impair language processing and limited visibility due to environmental conditions necessitate the use of non-verbal methods of communicating affect to survivors located during search and rescue operations.