Nielsen's 3 UX Cliffs Mapped to Voice AI: 100ms Feels Instant, 300ms Alive, 800ms Dead

Jakob Nielsen's 1993 response-time thresholds (0.1s / 1s / 10s) still hold in 2026, but the numbers shrink once you strip the screen away. Here's how the GUI cliffs translate to voice AI, why 300ms is the new 1-second, and where current voice agents still fall off the edge.