Speech Feedback Reduces Driver Distraction Caused by In-vehicle Visual Interfaces

Driver distraction and inattention are the main causes of accidents today and one way for vehicle manufacturers to address this problem may be to replace or complement visual information in in-vehicle interfaces with auditory displays. In this paper, we address the specific problem of giving text input to an interface while driving. We test whether the handwriting input method, which previously has been shown to be promising in terms of reducing distraction, can be further improved by adding speech feedback. A driving simulator study was carried out in which 11 persons, (3 female) drove in two different scenarios (curvy road and straight motorway) while performing three different handwriting text input tasks. Glance behavior was measured using a head mounted eyetracker, and subjective responses were also acquired. ANOVA Analysis revealed that speech feedback resulted in less distraction as measured by total glance time compared to the baseline condition (no speech). There were however also interaction effects which indicated that the positive effect of speech feedback were not as prominent for the curvy road scenario. Post-experiment interviews nonetheless showed that the participants felt as if the speech feedback made the text input task safer, and also that they preferred speech feedback over no speech.