SynthID on every Gemini TTS clip: keep the original file for ad review
Google marks every Gemini 3.8 TTS clip with SynthID and C2PA credentials. What that means for ad voiceovers, and what Sume docs do and do not say.
Google says every clip from Gemini 3.8 TTS carries a SynthID watermark and C2PA credentials, and voice replication needs consent verification. Keep the untouched original next to any edit so an ad reviewer can check provenance. Neither Google's pages nor Sume's docs say the watermark survives re-encoding or mixing.
What Google states
From the announcement: SynthID on every clip, C2PA credentials, and consent checks for voice replication from 30-second samples. It also lists regions where replication is unavailable, including Illinois, Texas, the EEA, UK, Switzerland and India.
What is not stated
We found no statement of how SynthID behaves after trimming, loudness changes, mp3 conversion or mixing under music. Treat survival as unknown, not as a guarantee, and do not tell a client otherwise.
| Claim | Source says |
|---|---|
| Watermark on every clip | Yes, SynthID (Google) |
| C2PA credentials | Yes (Google) |
| Survives edits | Not stated |
| Sume adds a watermark to TTS | Not stated in the docs we read |
A practical archive habit
Store the raw vendor file, the script text, the voice and style settings, and the edit you shipped. If you finish a spot on Sume, the timeline audio join or trim is a separate job with its own output, so the raw clip stays intact as long as you keep it. Sume does not claim to add or preserve a watermark, so do not rely on it for that.
Sources
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Written by Sume