Comparing Time To Collision estimates: Experiments in a Wave Field Synthesis Laboratory and the Real World Environment

Prior studies have examined pedestrian behaviour using Time to Collision (TTC) estimates in simulated traffic scenarios, employing spatial audio rendering techniques such as Wave Field Synthesis (WFS). However, the validation of these findings requires real-world experimentation. In this study, participants experienced traffic scenarios in two different environments, where an electric vehicle was approaching at controlled speeds in an auditory-only setting. In the real-world setting, participants stood on a curb with a safe distance to the street. The driving-by-sound should only be audible through open headphones within a specific time interval. Thus, before the vehicle's approach should be audible and after the vehicle crosses a defined distance before the listener's position, adjusted Pink Noise was used for masking. Additionally, the participants were equipped with a Head Mounted display, enabling them to estimate the TTC by pressing a button and hiding visual cues. Secondly, the same traffic scenarios were simulated in the WFS laboratory with close-up sub-source sounds of the vehicle. The participants had the task to estimate TTCs of the simulated traffic scenarios as well. The comparison of TTC results underscores the strengths of the traffic simulations and the capabilities of state-of-the-art sound auralisation laboratories.