How to Remove Background Noise In Audacity

Make your podcasts sound professional

Microphone in front of a blurred/bokeh audio recording screen

Pixabay

If you record podcasts, you probably already know about Audacity. If not, Audacity is one of the most popular open source (and free), cross platform recording tools on the market. Out of the box, Audacity does a great job of recording your audio. However, with a simple trick, you can take your recordings to the next level.

Said trick is removing ambient (background) noise from the recording. Once you start using this trick, you’ll be shocked at how much better your recordings sound.

Version Information

We will demonstrate this process on Audacity, version 2.2.2. As long as you are using any version newer than 2.0, you should be good to go with this process.

What Is Background Noise?

The first thing is to understand what ambient noise is. Simply put, ambient noise is the constant hum of the world around you. You may not notice it, because you hear it all the time. It’s your AC, your refrigerator, the aquarium in your office, the hum of lights or computer fans. In other words, it’s a steady stream of noise. To get an ideal recording environment, you need to get rid of those sounds. However, you don’t want to have to shut off your AC (in the summer) or your heat (in the winter) to get you recording up to professional levels. And there might be ambient sounds you have no control over (for instance if you’re recording in an office and cannot shut off the lighting or other machines cranking out noise). For those instances, you need to depend on your recording software to remove the noise.

What Background Noise is Not

Background noise is not random sounds, like dogs barking, a train, footsteps on the floor above you, a doorbell, or the clicking of keyboard keys. These sounds must be removed manually (and can take significant time to extract).

How to Remove Background Noise

Now that you understand what background noise is, let’s remove it. I will assume you already have a recording at the ready. You’ll want to do this before you convert the file to .mp3, .wav, or whatever format you require. In other words, this will be an .aup file (which is broken into tracks).

Screenshot of the Audacity recording tool.


The process for removing background noise goes like this:

  1. Highlight a section of the recording (about 1-2 seconds minimum) that doesn’t have any voices or sounds pertaining to the recording (in other words, blank space).

    Screenshot of the selected region in Audacity.
  2. Click Effect and then click Noise Reduction.

    Screenshot of the Audacity Effects menu.
  3. Click Get Noise Profile.

    Screenshot of the Noise Reduction window.
  4. Select your entire recording by clicking Ctrl + A on your keyboard.

    Screenshot of the entire recording selected.
  5. Click Effect and then click Noise Reduction.

    Screenshot of the Audacity Effects menu.
  6. Click OK.

    Screenshot of the Noise Reduction window.
  7. Allow Audacity to complete the process.

At this point, Audacity will remove the noise using to the Noise Profile you created (which was done by clicking Get Noise Profile). That Noise Profile is a sample of ambient noise picked up by your microphone. Depending on how long your recording is, this can take seconds or minutes.

When the process completes, give your recording a listen and you’ll find it sounds exponentially better. With all that background noise removed, your podcast will sound cleaner and much more professional.