How to Capture a Noise Profile in Audacity

Capturing a noise profile is the crucial first step in eliminating unwanted background hums, hisses, and ambient room sound using Audacity's Noise Reduction effect. This guide explains how to isolate an audio sample containing only background noise, teach the software what frequencies to remove, and prepare your track for clean audio processing.

1. Record Room Tone

Before recording your main audio, record a few seconds of pure room tone without speaking or moving. If you have already finished recording, locate a brief pause in the track—ideally between one and three seconds—that contains only the unwanted background sound you want to eliminate.

2. Highlight the Noise Sample

Use the Selection Tool (shortcut key F1) to highlight the quiet section containing only the background noise. Ensure that no breathing, mouth clicks, or intended audio elements fall within this selection, as selecting them will cause Audacity to remove those frequencies from your entire project.

3. Open the Noise Reduction Tool

With the noise sample highlighted:

  1. Navigate to the top menu and click Effect.
  2. In Audacity 3.2 and newer, select Noise Removal and Repair, then click Noise Reduction. (In older versions, click directly on Noise Reduction).

4. Click "Get Noise Profile"

In the dialog box that appears, you will see a two-step interface. Locate Step 1 and click the Get Noise Profile button. The window will close automatically once the profile has been analyzed and saved to Audacity's temporary memory.

5. Apply the Reduction to Your Track

Once the profile is captured:

  1. Select the audio you wish to clean (press Ctrl + A on Windows or Cmd + A on Mac to select the entire track).
  2. Reopen the tool via Effect > Noise Removal and Repair > Noise Reduction.
  3. Move to Step 2, configure your preferred settings for Noise Reduction (dB), Sensitivity, and Frequency Smoothing, then click OK to apply the filter.