Unverified50% confidenceOpinionExact time
The industry generally believes that when time to first audio (TTFA) is below 300ms, conversation is already close to the rhythm of human turn-taking, and at 150ms it is almost imperceptible as machine latency.
1
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50%
Confidence
Long-term
Relevance
10/13/2026
First Seen
Sources
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Related Claims
UnverifiedConversational AI applications typically require TTFA to be below 300ms; otherwise, users will noticeably perceive a pause.76% similarVerifiedThe human perceptual tolerance threshold for latency in natural conversation is approximately 300 milliseconds.75% similarUnverifiedElevenLabs' released Eleven v4 Turbo has a median time to first audio (TTFA) latency of about 150 milliseconds in the official WebSocket benchmark tests.74% similarUnverifiedA Time to First Token (TTFT) below 500ms is generally considered a smooth interactive experience, while exceeding 2 seconds creates a noticeable sense of waiting.74% similarVerifiedThe end-to-end latency of full-duplex voice AI must be controlled within 150 milliseconds; otherwise the human ear will perceive a noticeable lag.73% similar
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