Pedestrians can only safely cross the road before an approaching vehicle if the time remaining until the vehicle arrives at their position (time-to-collision, TTC) is longer than the time needed for crossing. Using a virtual-reality system that combines physically plausible acoustic simulations of approaching vehicles with visual simulations, we are investigating how the vehicle sound affects the perception and behavior of pedestrians in a road-crossing situation. This talk presents an overview of our research approach and of key findings from the first phase of the AUDICTIVE priority program. One series of experiments studied the effects of vehicle source intensity on TTC estimation and the riskiness of street-crossing decisions, indicating potential risks associated with quieter vehicles. A second series focuses on interactions between pedestrians and accelerating vehicles. When the sound of an accelerating conventional vehicle (ICEV) is presented, this largely removes the inadequate consideration of acceleration observed in visual-only TTC estimation. However, for electric vehicles with and without AVAS (acoustic vehicle alerting system), this benefit provided by the car sound is significantly reduced compared to ICEVs, and riskier crossing decisions are observed. Implications for the design of AVAS sounds are discussed.