Sonically-enhanced in-vehicle air gesture interactions: evaluation of different spearcon compression rates

Driver distraction is a major contributor to road vehicle crashes, and visual distraction caused by using in-vehicle infotainment systems (IVIS) degrades driving performance and increases crash risk. Air gesture interfaces have been developed to mitigate driver distraction, and using auditory displays showed a decrease in off-road glances and an improved perceived workload. However, the potential of auditory display was not fully investigated. The present paper presents directional research in the design of auditory displays for air-gesture IVIS through a dual-task experiment of driving a simulator and air-gesture menu navigation. Twenty-four participants utilized the in-vehicle air gesture interfaces while driving with four auditory display conditions (text-to-speech, 70% compressed spearcons, 40% compressed spearcson, and no sound). The results showed that 70% spearcon reduced visual distraction and increased menu navigation accuracy but with increased navigation time. 70% spearcon was most preferred by the participants. Driving performance or workload did not show any difference among the conditions. Implications are discussed with the design guidelines for future implementations.