How do I add sound effects to a video automatically?

Upload the video to Valmera and ask for sound design ("add sound effects where they help") or name a sound and a moment ("a camera shutter when the photo appears"). The agent ties each effect to a visible event, picks a real recording by comparing waveforms, places it and checks the preview. Then you export a full-quality MP4.

Will the AI add sound effects I didn't ask for?

Only where they serve the edit. Ask for sound design and the agent decides where effects help; on a hype, montage or promo brief it may add a few on its own judgment. Every effect is tied to a visible event, the agent never adds sounds just to fill silence, and "no sound effects" keeps the edit dry.

Can I use these sound effects in commercial videos?

Check each sound's license, which the agent tells you when it places it. Public-domain sounds have no conditions, credit-required sounds need the creator credited in your caption or description, and non-commercial sounds are not for monetized or business content. Sounds that forbid adaptation are never offered. For client or ad work, ask the agent to skip non-commercial sounds, or upload effects you have licensed.

How loud are the sound effects, and do they duck under my voice?

Each effect goes in at −6 dB by default; clicks and soft whooshes usually sit around −10 to −14 dB. Effects never duck, because an accent that dips under the word it punctuates stops being an accent; music is the layer that ducks under speech. If an effect fights your voice, ask for it quieter or on a different moment.

What happens to a sound effect if I cut the video again?

It moves with its footage. Trim six seconds before a whoosh and the whoosh slides six seconds earlier to stay on the same frame. If its moment is cut away entirely, the effect is removed and the reply says so.

Can I use my own sound effect files?

Yes. Upload MP3, WAV, M4A, AAC or OGG files up to 500 MB, or send a video clip and use its sound, then say where each one goes. The agent places and levels your file like any other effect. Creating an account and uploading are free. Editing requires a subscription.

Add Sound Effects to Video Automatically with AI

To add sound effects to a video automatically, upload it to Valmera and ask for sound design, or name the sound and the moment. The AI agent finds the moments a viewer sees (cuts, reveals, on-screen clicks, text landing), searches real recorded effects for each one, auditions the candidates by their actual waveforms and places the best match on the exact frame. Where every option weakens a moment, it leaves that moment dry.

Every effect is a real recording from Freesound’s library or a file you upload, and the agent tells you each sound’s license terms.

Sound Design in One Request

Upload, ask for sound effects, review the preview. Creating an account and uploading are free. Editing requires a subscription.

Create an account →

See pricing →

How to Add Sound Effects to a Video Automatically

1
Upload the video
MP4, MOV, M4V, MKV or WebM, up to 100 GB and 3 hours. Valmera indexes it once: a word-level transcript, shot changes and frames, so the agent knows where the cuts, reveals and stressed words are.
2
Ask for sound design, or name a moment
“Add sound effects where they help” lets the agent choose. “A camera shutter when the photo appears” names one effect and its moment.
3
The agent picks, auditions and places
It ties each effect to a visible event, searches real recordings by the sound’s physical name, compares the candidates’ waveforms and places the winner at −6 dB, or keeps the moment dry.
4
Review the preview
The agent renders a preview and checks the mix before it replies. Then adjust in plain English: “the whoosh is late,” “quieter clicks,” “remove the pop at 0:31.”
5
Export
When it sounds right, export a full-resolution MP4 rendered from your original file, with the effects mixed in.

PROMPTS TO PASTE

Add sound effects where they help: a whoosh on each scene change and a pop when each title lands. Keep them subtle.

Add a soft click on every button press in the screen recording, well under my voice.

Build a riser into the logo reveal at 0:42 and land an impact on the reveal.

The whoosh at 0:14 is late and too loud. Move it 0.3 seconds earlier and drop it to -10 dB.

Where Sound Effects Go in an Edit

A sound effect marks something the viewer sees or the music does. This is the map the agent works from, and the one to use when you place effects yourself.

Event on screen	Typical sound	Placement tip
Scene change or transition	Whoosh, swish	Start it a few frames early. A whoosh peaks mid-sound, so the peak, not the first frame, should hit the cut.
Reveal: logo, product, result, big number	Impact, boom, hit	Attack on the reveal frame, with the tail decaying over what follows.
Build-up into a reveal or drop	Riser, swell	Start about two seconds ahead and resolve exactly on the change. A riser that ends in more talking promises a payoff that never comes.
On-screen click or tap	Mouse click, UI tap	On the actual click and well under the voice, often −10 to −14 dB.
Text, caption or graphic landing	Pop, blip, tick	On the frame the element lands. If you consciously notice it, it’s too loud.
Photo, screenshot or freeze frame	Camera shutter	On the freeze or the flash frame.
The line you want remembered	Impact, ding	On the stressed syllable. Word-level timestamps give its exact start.

Three sounds, one cut, three different starting points.

Rate matters more than any single choice. A few well-placed accents read as sound design; one on every cut reads as a template. Sound already in the shot often tells the truth better than an added effect: a real door, a crowd or game audio can carry the moment on its own, and the agent keeps it when it does.

How the Agent Picks the Moment and the Sound

Moment first. Every effect is tied to a nameable event: a join in the edit, a word’s exact start from the transcript, or a reveal found in the indexed frames. If the agent can’t name the event, the sound doesn’t go in.
Real recordings, searched by physical name. “Whoosh,” “camera shutter,” “keyboard click”: the agent searches Freesound’s library of recorded effects through Openverse, capped at 15 seconds by default.
Auditioned by waveform. Candidates are downloaded and compared on attack, peak position, tail, crest, spectral balance, bass and whether the file holds one clean event or several, against the purpose of the moment.
Placed, or left dry. The winner goes in at −6 dB on the edited timeline and plays once. One call (add_web_sfx) does the search, comparison and placement for a single moment and can decide the moment is stronger without a sound. For a full pass, the agent searches, auditions, downloads and places each sound in turn.
Checked before it replies. The agent renders a preview and checks the mix’s measured loudness and peaks.

Settings You Can Change

Setting	Default	How to change it
Moment	The visible event the agent chose, on the edited timeline	“Move the whoosh 0.3 seconds earlier.” Retiming keeps the same sound and level.
Level	−6 dB; clicks and soft whooshes usually sit lower	“Make the clicks quieter,” or an exact value: “−12 dB.”
Purpose	The event the sound marks, such as “logo reveal”	Stored with each effect so the final mix review can check it still lands on something. “That pop isn’t on anything. Remove it.”
Start point in the file	The beginning of the file	For a long recording or a clip whose hit comes late: “use the slam 3.2 seconds into door.wav.”
Sound choice	The best match from the audition	“Try a drier one,” “public domain only,” or “use the swoosh.wav I uploaded.”
Length cap	15 seconds	Raise it for ambience, up to 60 seconds: “a 30-second crowd bed under the intro.”

Limits

Valmera doesn’t synthesize sound effects: every effect is a real recording or a file you upload. It relays each sound’s license but doesn’t grant one, so check the terms before commercial use. Each effect has timing and level controls only, with no per-effect EQ, reverb, pitch or fades, so shape a sound before you upload it. A sound placed near the very end loses any tail that runs past the last frame, and you’re told when that happens. There’s no audio denoise, so effects can’t rescue a noisy recording.

Sound Effects in the Rest of the Mix

Sound effects are one layer. In the same chat you can add music that ducks under speech, pair whooshes with transitions on scene changes, and add click sounds to a product walkthrough captured with the website demo recorder, whose recorded clicks give exact timing. Wondering whether an AI generator would do better? Read AI sound effect generators vs real recordings. Every level and default is in the audio and music docs, and the TikTok creators guide shows sound design in short-form edits.

Using Claude, ChatGPT or Cursor? The same add_web_sfx, search_sfx, audition_sfx_candidates and add_sfx tools are available through Valmera’s MCP server.

Creating an account and uploading are free. Editing requires a subscription — see plans.