Enhancing User Experience of Virtual Keyboard Through Collaborative and Speed-Adaptive Auditory-Vibrotactile Feedback

Due to the limited internal space and economic costs, virtual keyboards(VKs) of mobile devices commonly use monotonous global sound and vibration feedback, resulting in unsatisfactory realism and negative experience. To mitigate the monotonous feedback of high-frequency keystrokes on VKs, we propose an interactive sound-vibrotactile feedback design. This system dynamically adjusts sound and vibrotactile re-sponses based on the user's typing speed. We conducted a user study (N=30) and found that the collaborative varied auditory-vibrotactile feedback provided a better experience, created a local feedback illusion, and improved global feedback. Additionally, users preferred subtle variations over distinct variations. Our method can improve global VK feedback and provide a better experience without increasing additional costs and burdens. This study contributes to improving the VK experience on low-cost mobile devices and provides design suggestions for VKs.