# Audio leveler: even out loud and quiet voices

Make every voice equally loud, from one recording or a track for each person.

Tool: Level speakers (`level_speakers`). Price: 1 credit a minute of input for whole files, charged only when a job succeeds.

## Free API

```bash
curl -F file=@podcast.wav https://audo.ai/api/try/level-speakers -o podcast-leveled.wav
```

Free for the first 3 minutes of each file, 3 times a day per person, with no key or account. Uploads up to 100 MB, 2 at once from one address. The response is the result itself; a job that runs longer than about 30 seconds returns 202 with a link to check on it. With an API key (`-H "Authorization: Bearer $AUDO_API_KEY"`), the same request processes the whole file with credits. Details: https://audo.ai/docs/api.md

## Options

Form fields with the same names as the MCP tool's inputs:

- `track_file_ids`: Per-person tracks instead, one speaker each, such as ["file_8Kc2QmP4", "file_3Jd9RtY2"]. 2 to 10 tracks; each comes back leveled as its own file.
- `target`: The loudness it finishes at: podcast (-16 LUFS), streaming (-14 LUFS), broadcast (-23 LUFS), or custom (set custom_lufs). Default podcast.
- `custom_lufs`: The loudness for target custom, in LUFS (-30 to -5), such as -18.
- `within_speaker`: Also evens out slow changes within each speaker, such as leaning away from the mic: up to 6 dB, measured on their speech only and held through pauses. Default false.
- `output_format`: The result's format: same (as the input; a video stays a video), wav, mp3, m4a, or flac. Default same.

## Languages

Any language: it works on the sound, not the words.

## From an assistant (MCP)

Add https://audo.ai/mcp and sign in (setup for each assistant: https://audo.ai/setup.md). The tool is `level_speakers`:

> Evens out loud and quiet voices: each speaker (found automatically) or each per-person track gets one steady gain from their own speech loudness, changing smoothly between speakers, then a standard loudness. Music and background get one steady gain, and pauses aren't raised above the speech around them. Use it when one voice is much quieter than another. Not for one overall loudness (adjust_loudness). Set free to true for the first 3 minutes free, 3 times a day; otherwise 1 credit a minute. Returns job_id; the result has each speaker's loudness and gain, and the gain curve.

Example: "Use Audo to even out the host and guest in podcast.wav."

## More

- Every tool: https://audo.ai/llms.txt
- OpenAPI: https://audo.ai/api/openapi.json
- This page for people: https://audo.ai/audio-leveler