Realtime Voice And Turn Taking

Default startSpeakingPlan.waitSeconds is short. On a noisy call, the assistant starts speaking over the customer's last syllable on most turns.

Raise startSpeakingPlan.waitSeconds (e.g., 0.4 → 0.8) and enable transcriptionEndpointingPlan.smartEndpointingEnabled if available so end-of-turn is detected from transcript shape, not just silence. Validate by measuring interruption rate in artifact.messages[] before/after.

Long customer monologue — assistant stays silent for 30 seconds. Customer says 'are you still there?'

Enable backchanneling (mm-hmm / right / I see) on the assistant so the agent vocalizes presence without taking the turn. Configure acknowledgementPhrases or rely on the documented default — verify in artifact.messages[] that backchannel tokens fire mid-monologue, not after.

Customer says 'wait —' and the assistant keeps talking for another 4 seconds before stopping. Operator wants snappier interruption.

Lower stopSpeakingPlan.numWords (e.g., 2 → 1) so the assistant aborts TTS after the first user word, and verify stopSpeakingPlan.voiceSeconds and backoffSeconds are low. Test with deliberate barge-ins; measure assistant.speech.interrupted hook firing latency.