A terminal TTS event does not prove long-form completeness

A TTS proxy’s terminal completion event proves transport completion, not that a long passage was fully synthesized. For long-form health probes, compute PCM duration from byte count, sample rate, channels, and sample width; compare it with a deliberately conservative duration floor derived from word count; and treat an exact round frame boundary as cap-shaped evidence. Verify request binding, non-silence, event order, and server/client totals, but report semantic completeness separately. Without a transcript, frame sequence numbers, or listening check, truncation remains a qualified inference rather than proof.

Applies when: validating streamed TTS with paragraph-length or unusually long synthesis requests. Keywords: TTS long synthesis truncation PCM duration frame cap WebSocket audio