Toward Enabling Natural Conversation with Older Adults via the Design of LLM-Powered Voice Agents that Support Interruptions and Backchannels

Voice agents can construct meaningful conversations with older adults to offer various benefits, such as providing emotional companionship and assisting with memory recall. However, such conversations often follow the simple turn-taking pattern and lack interruption and backchannel of natural human conversation. Previous research has shown that this rigid turn-taking pattern lacks interactivity and initiative, limiting the flexible communication between older adults and voice agents. To address these issues and create a more natural conversational voice agent, we first conducted a formative study to identify common usage of interruption in the natural conversations of older adults. We then designed an LLM-powered Barge-in agent that supports interruption and backchannel. Our within-subject exploratory study showed that participants felt that conversations with Barge-in agents were more natural, engaging, and fluent than with the No barge-in agent. We further present design implications for creating more natural and human-like voice agents for older adults.