Should Voice Agents Be Polite in an Emergency? Investigating Effects of Speech Style and Voice Tone in Emergency Simulation

Research in human-agent interaction highlights the significance of agents’ politeness in enhancing social engagement and interaction satisfaction. It remains unclear, however, if agents should maintain politeness even in time-constraint situations. This study explores how a voice agent should deliver instructions for emergency evacuation using a between-subjects experiment in which we manipulated agent speech style (politeness: positive vs. negative vs. direct) and voice tone (urgency: high vs. low) and measured the effects on users’ perceptions of the agent and their cognitive workload. We found that the urgency of the agent’s tone had a positive effect on the perceived anthropomorphism, likability, and intelligence of the agent while reducing the required effort and frustration to complete the tasks. Urgent voices increased the cognitive trust and likeability of the agent when the agent used negative politeness for instructions. Our findings provide guidelines for designing voice agents for emergencies.