The objective of this study was to investigate if 3D auditory displays could be used to enhance parking assistance systems (PAS). Objective measurements and estimations of workload were used to assess the benefits of different 3D auditory displays. In today’s cars, PAS normally use a visual display together with simple sound signals to inform drivers of obstacles in close proximity. These systems rely heavily on the visual display, as the sound does not provide information about obstacles' location. This may cause the driver to lose focus on the surroundings and reduce situational awareness. Two user studies (during summer and winter) were conducted to compare three different systems. The baseline system corresponded to a system normally found in today’s cars. The other systems were designed with a 3D auditory display, conveying information of where obstacles were located through sound. A visual display was also available. Both normal parking and parallel parking was conducted. Time taken for parking and the number of obstacles/curb hits were recorded. Participants answered a NASA TLX questionnaire after evaluating each PAS for estimation of their experienced workload. Most participants enjoyed the additional information provided by the 3D auditory displays. The winter trial showed a significant reduction in perceived effort when using a 3D auditory display compared to the baseline. The summer trial showed tendencies of higher mental demand and frustration with the baseline compared to the 3D auditory displays. The results suggest that 3D auditory displays can be appreciated and useful in difficult parking situations.
