Bring the VibeOn: Designing a Multimodal Interface for Shared Emotional Experiences in Live-streamed Concerts

Live-streamed concerts have become a new cultural phenomenon, yet they struggle to replicate the collective emotional experience of in-person events. Traditional text-based chats often cause information overload and distraction, diminishing the sense of shared experience. To address this challenge, we present VibeOn, a multimodal interaction system designed to foster collective engagement and socio-emotional connection among remote audiences. Developed through a formative study and an iterative design process, VibeOn integrates features such as chat and emoji recommendations, chat highlights, avatar-based cheering, ambient visualization, and concert-specific layout. A user study with 40 participants demonstrated that VibeOn significantly enhanced social connectedness, sense of community, and collective effervescence compared to a conventional chat interface, while maintaining high usability. Our findings indicate that VibeOn enables audiences to feel a shared, extraordinary experience beyond simply watching, highlighting its potential to enrich collective emotions in large-scale online events.