Decision Framework
Voice wins: urgency, accessibility, high-intent transactions, populations preferring phone, complex emotional handling. Chat wins: multi-step workflows, reading/comparing, follow-up channels, asynchronous resolution.
Latency Posture
Voice demands sub-second response. Chat tolerates 2-3 seconds. Chat allows ‘typing…’ and thinking time. Voice awkwardness grows if the AI pauses. Infrastructure choices differ by latency budget.
Cost per Interaction
Voice AI typically 3-5x cost of chat AI (TTS, ASR, longer conversations). But voice often resolves faster than 3-5 chat messages — depends on interaction shape. Calculate per your actual workload.
Deployment Strategy
Most enterprises run both. Voice handles urgent support, chat handles informational self-service. Handoffs between — ‘start in chat, escalate to voice’ — remain friction points. Design handoffs carefully.