Voice+Tactile: Augmenting In-vehicle Voice User Interface with Tactile Touchpad Interaction

Promisingly, driving is adapting to a Voice User Interface (VUI) that lets drivers utilize diverse applications with little effort. However, the VUI has innate usability issues, such as a turn-taking problem, a short-term memory workload, inefficient controls, and difficulty correcting errors. To overcome these weaknesses, we explored supplementing the VUI with tactile interaction. As an early result, we present the Voice+Tactile interactions that augment the VUI via multi-touch inputs and high-resolution tactile outputs. We designed various Voice+Tactile interactions to support different VUI interaction stages and derived four Voice+Tactile interaction themes: Status Feedback, Input Adjustment, Output Control, and Finger Feedforward. A user study showed that the Voice+Tactile interactions improved the VUI efficiency and its user experiences without incurring significant additional distraction overhead on driving. We hope these early results open new research questions to improve in-vehicle VUI with a tactile channel.