Auditory displays in human-machine interfaces

Auditory displays are described for several application domains: transportation, industrial processes, health care, operation theaters, and service sectors. Several types of auditory displays are compared, such as warning, state, and intent displays. Also, the importance for blind people in a visualized world is considered with suitable approaches. The service robot domain has been chosen as an example for the future use of auditory displays within multimedia process supervision and control applications in industrial, transportation, and medical systems. The design of directional sounds and of additional sounds for robot states, as well as the design of more complicated robot sound tracks, are explained. Basic musical elements and robot movement sounds have been combined. Two exploratory experimental studies, one on the understandability of the directional sounds and the robot state sounds as well as another on the auditory perception of intended robot trajectories in a simulated supermarket scenario, are described. Subjective evaluations of sound characteristics such as urgency, expressiveness, and annoyance have been carried out by nonmusicians and musicians. These experimental results are briefly compared with time-frequency analyses.