noise_reduce

Removes steady background noise (hum, hiss, air conditioning) from an audio or video source.

Tip: The edit processor can also clean up noise with its reduce_noise operation, and can chain it with other adjustments in a single step. Use edit when you want to combine several adjustments; this processor remains available and unchanged.

When to use

Use when source audio has background noise (HVAC hum, room tone, camera noise). Run after chroma keying and before transcript generation for cleanest results.

In the editor

Add it from the Library (Audio group), or with + add step and a search for noise_reduce, before the step that transcribes your audio: a cleaner recording transcribes better.

Under Inputs, add source, either as a file input naming the recording or as a step input pointing at the step that placed it. nr is how hard it works (start at 8; above 20 tends to sound processed), and nf describes how loud the noise floor is. level narrows it to one timeline level if you only want to clean one of them.

No new clips appear in the run timeline. The same clips play with the hum removed, because the step quietly swaps in a cleaned copy of the audio behind them. Cleaning takes a while and gives the same answer every time, and steps save their output by default, so a second run in the same run group reuses it instead of doing the work again.

YAML Example

- id: denoise
  processor: noise_reduce
  input:
    - id: source
      step: chroma_key
  params:
    nr: 8
    nf: -30
    level: main
  cache: true

Inputs

Params

Output

SourceRemaps: substitutes original source file paths with denoised versions.

Notes

• Adapts to the noise it hears, so you do not have to supply a sample of the noise.
• Start with nr: 8 and increase gradually. Values above 20 often sound unnatural.
• Use cache: true: denoising is slow and deterministic.