How to Generate AI Video with Sound, Speech and Dialogue
MyDreamVid · 2026-09-11
Most people discover AI video through silent clips, then spend an evening in an editor adding sound. Seedance generates audio with the video: ambience that matches the scene, effects synced to the action, and — the part that surprises everyone — spoken dialogue.
Getting speech into a clip
Put the words in quotes, in the prompt. That's it:
A street vendor stirs a steaming pot and calls out, "hot noodles, last pot tonight!"
The line is spoken with natural intonation, and this works even on the cheapest model (2.0 Mini). Tone can be steered with plain description — whispers, shouts over the rain, says wearily.
The animal-talking trick
One tested pitfall: if you ask for an animal whose "mouth moves in sync with the words", models tend to graft eerily human lips and teeth onto the animal, because almost all lip-sync training footage is of human faces. The fix is a voice-over construction:
The kitten's voice is heard as a voice-over; its mouth stays a natural cat mouth with only tiny movements, no human-like lips or teeth. Small head tilts and ear twitches while it "speaks".
You keep the charm and lose the body horror. Seedance 2.5 also follows "keep the mouth natural" constraints more obediently than Mini or Fast.
What audio costs
Audio is on by default, and the pricing differs by model — this is worth knowing before you commit to a long clip:
- Seedance 2.0 Fast and 2.0 Mini: audio is free — the price is identical with audio on or off.
- Seedance 2.5 and 2.0: audio roughly doubles the price of the clip. Turn audio off on these models when you're drafting visuals, and turn it on for the final render.
Either way, the generator quotes the exact credit cost for your actual settings before you start — the pricing page has the per-second table.
Reference audio: setting the rhythm
In reference-to-video mode you can attach an audio file (up to 5 minutes) and point to it in the prompt — "@Audio1 sets the rhythm" — useful for cutting motion to a beat. Note that reference audio is billed on top of the output by its own length, and the quote shows that addition separately before you generate.
When to add sound in an editor instead
Generated audio is scene sound — ambience, effects, dialogue. For a licensed music track, precise narration, or a multi-shot film's continuous score, export your clips (the film workspace gives you a ZIP of shots plus a rough-cut MP4) and lay the track in any editor. Generated ambience underneath a music bed usually mixes fine.
Frequently Asked Questions
Does every model support audio?
Yes — all four Seedance video models generate audio, with native audio being a particular strength of 2.5.
Can I turn audio off?
Yes, per generation. On 2.5 and 2.0 that roughly halves the price; on Fast and Mini the price doesn't change.
Can it clone a specific voice?
No — voices are generated to fit the scene, not cloned from samples, and impersonating real people is against the content policy.
The dialogue came out in the wrong mood. How do I fix it?
Direct it like a screenwriter: put the delivery in the prose around the quote — "she says flatly, without looking up, 'I know.'" — and regenerate. Drafting on Mini keeps these retries cheap.