Your voice agent has 300ms before users bail -- the three latency cliffs that kill voice UX

I watched 30 users talk to the same voice agent Same script. Same questions. The only thing I changed was the response latency: 300ms, 500ms, 800ms. At 300ms, people just talked. No awkward pauses, no confusion. One user didn't even realize it was an AI until I told her afterward. At 500ms, something shifted. Users started talking over the agent. They'd ask a question, wait half a second, then rephrase it -- which reset the entire processing pipeline and made the delay even worse. At 800ms, it w