Supplematary material for "Visual feedback for in-car voice assistants"

This study presents ambient visual feedback for automotive voice assistants to enhance driver interaction and safety through peripheral visual cues. A user interface prototype incorporating ambient colour feedback was evaluated through an online survey (N=151 from 28 countries) and a lab-based study (N=24, Belgium). Survey participants strongly preferred smartphone-integrated user interfaces, such as Android Auto and Apple CarPlay, over built-in manufacturer systems, indicating a desire for consistent digital ecosystems. In the lab, 18 participants favoured the ambient feedback over conventional or no visual feedback, citing improved visibility and assistance. Statistical analysis revealed that ambient feedback improved user visibility, position, and usefulness ratings. However, the need for auditory cues remained evident, confirming the importance of multimodal feedback. These findings suggest that ambient visual feedback is a promising direction for improving the usability of voice assistants and driver satisfaction while supporting safe in-vehicle interaction.

本研究针对车载语音助手设计了环境视觉反馈方案，通过周边视觉提示优化驾驶员交互体验并提升行车安全性。本研究针对搭载环境色彩反馈的用户界面原型开展了两项评估：一项是覆盖28个国家、共151名受访者的线上调研，另一项是在比利时开展的实验室研究（共24名参与者）。调研结果显示，相较于车辆原厂内置系统，受访用户更青睐集成智能手机的用户界面方案（如Android Auto与Apple CarPlay），这反映出用户对统一数字生态系统的需求。实验室研究中，18名参与者认为环境视觉反馈优于传统视觉反馈或无视觉反馈，并提及该方案提升了信息可视性与辅助效果。统计分析结果表明，环境视觉反馈可提升用户对反馈的可视性、位置合理性与有用性的评分。但用户对听觉提示的需求依然显著，这证实了多模态反馈的重要价值。上述研究结果表明，环境视觉反馈是优化语音助手可用性、提升驾驶员满意度并保障安全车内交互的极具潜力的发展方向。