A study of audio and visual context switch indicators in a multirobot navigation task

Fourteen users worked with an interactive multi-robot simulation to compare audio and visual context switch indicators. Context switching means the switching of the cognitive focus between mobile robots in order to supervise tasks associated with a particular robot. Depending on the complexity of the mission and the environment a context switch induces high mental workload. In this study two-context switch indicators with different modalities were compared in a concurrent navigation task with two semiautonomous small size robots. While the visual context switch indicator is embedded in the graphical user interface a separate binaural audio-based indicator was used to display the states of the robots to the left and right ears of the users. This approach is inspired by Wickens´s multiple resource theory hypothesizing that the auditory system may support parallel processing and possibly relieves the visual channel. The acquired performance and workload data show that the audio indicator is equivalently effective as its visual counterpart and therefore a serious alternative in user interface design for multi-robot systems.