How to use

Remove background noise in Audacity — step by step

1
Record or open your audio
Open your audio file or recording in Audacity. Make sure there is at least 0.5–1 second of silence (just background noise, no speech or music) at the beginning or end.
2
Select the noise sample
Click and drag to select the silent section with only background noise. This will be the noise profile.
3
Get the noise profile
Effect → Noise Reduction → click Get Noise Profile. Audacity analyses the selected section.
4
Select the entire track
Press Ctrl+A to select all, or drag to select the portion you want to clean.
5
Apply Noise Reduction
Effect → Noise Reduction. Set Noise reduction (dB) to 12–18 for light cleaning. Click OK. Listen to the result — undo and adjust if it sounds unnatural.

Settings guide

Noise Reduction settings explained

Noise reduction (dB): How much noise to remove. Start at 12 dB. Higher values remove more noise but can add artefacts.
Sensitivity: How aggressively noise is detected. Higher = more aggressive. Start at 6.
Frequency smoothing: Smooths the frequency spectrum. 3 is a good default. Reduces "musical noise" artefacts.

Too much noise reduction causes a "watery" or robotic sound. Always preview and use the minimum setting that removes the noise acceptably.

FAQ

Noise reduction questions

Noise reduction makes my voice sound robotic

The noise reduction (dB) setting is too high. Undo (Ctrl+Z), then redo with a lower value — try 6–10 dB instead of 18+. Also reduce sensitivity. The goal is removing background noise while keeping the voice natural, not removing all sound below a threshold.

How to remove hum (50/60 Hz) in Audacity

Use Effect → Notch Filter. Set Frequency to 50 Hz (Europe) or 60 Hz (Americas) and Q to 1. Apply. For harmonics, also apply at 100/120 Hz and 150/180 Hz. Alternatively, use a high-pass filter at 80 Hz to cut low-frequency rumble.

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