This report describes the results and conclusions of “Increasing Truck Driver's Awareness: Use of In-Vehicle 3D Sounds,” a Safety IDEA project aimed at developing and testing a system using in-vehicle three-dimensional (3D) sound as a technique for augmenting the truck driver’s situational awareness (SA). Sound insulation of the truck cab, designed to reduce noise, vibration, and harshness (NVH), coupled with the inherent limited visibility from inside the truck cab, can contribute to the reduction in the driver’s SA around the truck. The objective of this project was to test whether 3D sounds could be used effectively to increase the driver’s SA by providing traffic cues, i.e., different simulated traffic situations represented by auditory icons. Auditory icons are sound representations of real world, naturally occurring events. Icons representative of four road users (cars, bicyclist, pedestrians, and motorcycles) that a truck driver would typically encounter in traffic situations, were created and used to determine if a 3D sound system can increase the driver’s awareness of the traffic situation by hearing the road user’s location, and directional movement relative to the driver’s position in the vehicle. The investigation to implement, optimise, and test an in-vehicle 3D sound system was organized into two stages. Stage I consisted of creating and testing natural sounding 3D auditory icons. Test clinics were conducted in order to determine if participants could: • Recognize the 3D auditory icon (cue recognition) by matching the 3D sound to the representative road user (cars, bicyclist, pedestrian, and motorcycle). • Determine the road user’s location (cue detection) by matching the 3D sound to the sound source location. • Determine the road user’s direction of movement (cue projection) by indicating the spatial movement of the 3D sound. In analysing recognition accuracy, auditory icons resulted in high accuracy rates which indicate their intuitiveness and high degree of association to the intended object. The results also indicated that spatial movement, coupled with the context of a traffic scenario where a safety critical event could occur between truck and road-users, tended to increase the accuracy to assess situational awareness. Based on the results of Stage I, Stage II consisted of integrating the optimised 3D sound system into a truck cab in order to evaluate the effectiveness of the sound icons while conducting actual driving manoeuvres. The driving clinic was conducted on a test course that was designed to simulate a suburban neighbourhood delivery scenario. The results of Stage II indicated that, when analysing recognition accuracy, auditory icons resulted in high accuracy rates , thus demonstrating the potential to effectively use 3D sounds, under realistic driving conditions. All of the participants in this project commented that they felt that this type of system could be beneficial. However, there are concerns associated with disguisable sounds that are not impacted by other in-vehicle cab sounds, too many alarms/alerts associated with other vehicle systems increasing their annoyance levels, and the possibility of other potential interfaces (vocal/spoken word alert, visual display alert, etc.). These indicate areas where future investigation and technological advancements will be needed in order to integrate 3D sounds into production vehicles. (Author/publisher)
Samenvatting