Designing Robot Sound-In-Interaction: The Case of Autonomous Public Transport Shuttle Buses

Horns and sirens are important tools for communicating on the road, which are still understudied in autonomous vehicles. While HRI has explored different ways in which robots could sound, we focus on the range of actions that a single sound can accomplish in interaction. In a Research through Design study involving autonomous shuttle buses in public transport, we explored sound design with the help of voice-overs to video recordings of the buses on the road and Wizard-of-Oz tests in live traffic. The buses are slowed down by (unnecessary) braking in response to people getting close. We found that prolonged jingles draw attention to the bus and invite interaction, while repeated short beeps and bell sounds can instruct the movement of others away from the bus. We highlight the importance of designing sound in sequential interaction and describe a new method for embedding video interaction analysis in the design process.