Cornell University and Linköping University are using sound to improve autonomous buses' navigation and communication capabilities. Researchers found the timing of sounds is the critical factor in ensuring effective social engagement by autonomous buses in the Swedish town of Linköping. The researchers designed potential bus sounds through an iterative process.
They played various sounds through a Bluetooth speaker outside of a bus to alert pedestrians and cyclists to the vehicle’s approach, analyzed videos of interactions, and chose new sounds to test based on that information. They observed through video analysis that timing and duration, rather than sound type, were key to signaling the bus's intentions.
More information:
https://news.cornell.edu/stories/2023/04/autonomous-bus-sounds-its-all-about-when-not-how