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Text to video with sound — how native AI audio actually works

September 25, 2026

Older text-to-video tools rendered silent clips and left the audio to you. Current Veo-class models generate sound natively: footsteps, rain, room tone, short lines of dialogue, made together with the motion rather than added afterwards. nixm renders these clips from a described scene, with sound included at HD and 4K: about two minutes and one credit for HD, and the first one is free. What native audio still gets wrong is lip sync and specific songs.

What does "native audio" mean in AI video?

It means the model produces the sound and the picture together, from the same understanding of the scene. The splash lands when the water moves. The room tone matches the size of the room. Footsteps fall where the feet do. That is a different thing from the older pipeline of a silent clip plus a stock track laid on top, which never quite touches what is on screen. The practical difference is that a native-audio clip reads as finished the moment it renders.

Hear one

This clip was made in nixm by animating a single still with one click. Nothing was added in an edit afterwards; the sound arrived with the video.

Eight seconds, 1080p, sound generated in the same pass as the picture. The still it started from is on the image-to-video page.

What native audio does well

Ambience. Rain on glass, a busy street, wind in an open field, the hum of an empty room. This is where it is most reliable, because the sound is a direct property of the place.

Effects tied to motion. A door closing, a cup set down, a car passing. When the action is clear in the picture, the sound usually lands with it.

Score and mood. A light musical bed that follows the tone of the scene. It is useful for atmosphere, but it is not a track you chose.

Short dialogue. A line or two in quotes can come back spoken, in a voice that suits the character.

What it still gets wrong

Being straight about the limits saves credits.

Lip sync. On nixm it is still experimental, even on a still face looking at the lens. A moving mouth in a moving shot will not match. If the line matters, keep the shot still. If the motion matters, let ambience and effects carry it.

Specific songs. The model makes its own audio; you cannot hand it a particular track. If you need a known song, add it in an edit and accept that it will not be generated to the picture.

Long speeches. A clip is eight seconds, or up to fifteen for a scene. A paragraph of dialogue will not fit, and a separate voice-over is the better tool for narration. That is a different job, covered in AI video with voiceover.

How to prompt for sound

Describe what the scene sounds like as plainly as what it looks like. "Late-night diner, fridge hum, rain against the window, a cup set down" gives the model a soundscape. "A diner" leaves it guessing. A few habits help:

  • Name two or three sounds, not ten.
  • Say when you want quiet: "near-silent, just breathing".
  • Put any spoken line in quotes and keep it short.
  • Match the sound to what is on screen, since audio that has nothing to attach to tends to drift.

In nixm you do this in conversation rather than a prompt box. You describe the moment, compose the still together, and add the sound direction before it renders. The whole workflow is in how to make an AI video.

What it costs

On nixm, sound is included at both resolutions, with no audio surcharge:

  • An HD clip costs 1 video credit and renders in about two minutes.
  • 4K costs 2 credits and takes five to seven minutes.
  • A scene with characters you have cast costs 2 credits for 10 seconds or 3 for 15, also with sound.

Credits are one-time purchases that never expire. When you compare prices elsewhere, check whether audio is included, because a cheap silent clip is a different product. Pricing is in AI video with no subscription.

Try it

A new nixm account includes one free HD video with sound. Open the cinematic studio, describe a moment and what it sounds like, and listen to what comes back.

frequently asked

Can text-to-video AI generate sound?

Yes. Veo-class models generate native audio with the picture, including ambience, effects, a musical bed and short dialogue. nixm clips arrive with their sound included.

Is the audio synced to what happens in the clip?

Ambience and effects usually are, because sound and picture come from the same scene understanding. Lip sync is the exception: on nixm it is still experimental.

Can AI video generate dialogue?

Short lines, yes. Put the line in quotes and keep it brief. For narration or long speech, a separate voice-over is the better tool.

Can I choose the music?

Not a specific song. The model generates its own audio. To use a particular track, add it in an edit afterwards.

How long does text-to-video with sound take?

About two minutes for HD on nixm, five to seven for 4K, and ten to fifteen for a scene with cast characters.

Does sound cost extra?

Not on nixm. Audio is included at HD and 4K: 1 video credit for HD, 2 for 4K.

Can I try it free?

Yes. A new nixm account includes one free HD video with sound, no card required.

try it now — nixm makes cinematic ai video, with sound. no subscription. first video free.

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