Don't Be Alarmed: Sonifying Autonomous Vehicle Perception to Increase Situation Awareness

Lack of trust can arise when people do not know what autonomous vehicles perceive in the environment. To convey this information without causing alarm or compelling people to act, we designed and evaluated a way to sonify an autonomous vehicle's perception of salient driving events using abstract auditory icons, or "earcons." These are localized in space using an in-car quadraphonic speaker array to correspond with the direction of events. We describe the interaction design for these awareness cues and a validation experiment (\textit{N}=28) examining the effects of sonified events on drivers' sense of situation awareness, comfort, and trust. Overall, this work suggests that our designed earcons do improve people's awareness of in-simulation events. The effect of the increased situational awareness on trust and comfort is inconclusive. However, post-study design feedback suggests that sounds should have low levels of intensity and dissonance, and a sense of belonging to a common family.