Novel In-Vehicle Gesture Interactions: Design and Evaluation of Auditory Displays and Menu Generation Interfaces

Driver distraction is a major contributor to car crashes, and visual distraction caused by using invehicle infotainment systems (IVIS) degrades driving performance and increases crash risk. Air gesture interfaces were developed to mitigate for driver distraction, and using auditory displays showed a decrease in off-road glances and an improved perceived workload. However, the design of auditory displays was not fully investigated. This thesis presents directional research in the design of auditory displays for air-gesture IVIS through two dual-task experiments of driving a simulator and air-gesture menu navigation. Experiment 1 with 32 participants employed a 2x4 mixed-model design, and explored the effect of four auditory display conditions (auditory icon, earcon, spearcon, and no-sound) and two menu-generation interfaces (fixed and adaptive) on driving performance, eye glance behavior, secondary task performance and subjective perception. Each auditory display (within-subjects) was tested with both a fixed and adaptive menu-generation interface (between-subjects). Results from Experiment 1 demonstrated that spearcon provided the least visual distraction, least workload, best system usability and was favored by participants; and that fixed menu generation outperformed adaptive menu generation in driving safety and secondary task performance. Experiment 2 with 24 participants utilized the best interface to emerge from Experiment 1 to further explore the auditory display with the most potential: spearcon. 70% spearcon and 40% spearcon were compared to text-to-speech (TTS) and no audio conditions. Results from Experiment 2 showed that 70% spearcon induced less visual distraction than 40% spearcon, and that 70% spearcon resulted in the most accurate but slowest secondary task selections. Experimental results are discussed in the context of the multiple resource theory and the working memory model, design guidelines are proposed, and future work is discussed.