How to Remove Noise With Audacity

Download Audacity

You’ve got your recording finished and realized there’s a hum or hiss on one half of the recording. This quick tutorial will walk you how to import your audio into Audacity, split the stereo track and remove the noise.

Start by downloading Audacity from http://audacity.sourceforge.net for your operating system (Mac, Linux or Windows).

Open up Your Stereo Recording in Audacity

In this case we have an mp3 that was recorded from Skype via Piezo from Rogue Amoeba. It records your mic on one channel, and the Skype caller on the other channel.

Open up Your Stereo Recording in Audacity

Single Stereo Track

When we start, we have a single stereo track. You can see in the silence sections on the second track that the center line is thick – that should be a thin line, instead it’s actually noise. We want to remove that noise but only affect the second track.

Single Stereo Track

Split Stereo Track

Tap on the disclosure triangle next to the track name and select Split Stereo Track. This does not exist as an option in the menus up above, only under this disclosure triangle.

Split Stereo Track

Two Mono Tracks

Now that we have two mono tracks, select the track with the noise.

Two Mono Tracks

Select a Region of Pure Noise

Hopefully you have a good sample area, but Audacity can do amazing things even if only with a few seconds of data. You can see in the bottom track a grey area that I’ve selected as our noise profile.

Select a Region of Pure Noise

Select Effect and Noise Removal…

Select Effect and Noise Removal...

Click Get Noise Profile

When you click this, the window will go away and it won’t look like Audacity did anything at all, but in fact you’ve just told it, “this is what noise looks like”.

Click Get Noise Profile

Select the Entire Track

Select entire track, or all of the area where the noise is you want to remove. You should see a yelow border around the track if you’ve selected it properly.

Select the Entire Track

Open Noise Removal Again

Open Noise Removal Again

Click OK

Now that you’ve taught Audacity what noise looks like, you can do Step 2 which is telling it to actually remove the noise. The tricky maneuver here is to simply push OK. If you want to go wild and play with the controls, have fun, or just click OK like I do.

Click OK

Window You'll See During Noise Removal

Window You'll See During Noise Removal

Nice Clean Audio

Now you can see that in the same gap (and elsewhere) the line is thin, indicating visually that the noise is gone. If you find the audio is distorted as a result of the noise removal, you might want to go back and mess around with those controls.

Nice Clean Audio

19 thoughts on “How to Remove Noise With Audacity

  1. MHINA - May 21, 2017

    Thanks! this was very helpful

  2. Nitin Arora - May 28, 2017

    Well I am trying but my audio is so much mixed with the outside noise that I am not able to separate it out. Can you provide some help for such audio file?

  3. Allison Sheridan - May 28, 2017

    That’s the hardest thing, Nitin. If you don’t have a segment where you can sample just the noise, the only thing you can do is sample where there’s noise and real audio you want. The result will probably be awful. I wish I had a better answer for you. The lesson forward is to figure out how to eliminate the noise before recording. Also always do a test recording. Even with the technique I demonstrate, it will still sound sub-optimal, just not as bad.

  4. GOAT - June 22, 2017

    Thank you. it really helped me

  5. Kumar Paathak - June 22, 2017

    I have a video file (mp4) for which noise needs to be removed. Could you please help ?

  6. podfeet - June 22, 2017

    Kumar – you’ll need to use some kind of video editor to extract the audio from the video. High end apps like ScreenFlow and Final Cut Pro X can extract the audio but if you have QuickTime, you can open it there and choose File, Export, Audio Only. From there you can open the audio in Audacity to remove the noise. But then you’ll need a video editor to get the audio back into the video, right? I don’t know of free options to do that. If you had Final Cut Pro X, you could remove the noise while in the app, not needing Audacity at all. there may be free video editors out there that can do this but I’m not just familiar with the topic well enough to advise.

  7. Christina Carnet - June 25, 2017

    Is it possible to remove, if not, almost remove the instrumental to a song?

  8. Christina Carnet - June 25, 2017

    I’m using Noise Reduction and it’s not doing anything to my track.

  9. podfeet - June 25, 2017

    Christina – no, it’s not possible to remove an instrumental track from a song if all you have is a mono track. With the little information you’ve provided about using noise reduction I can’t possibly help you figure this out. Please describe exactly what you’re doing in detail and I might be able to help. I’ve seen it do bad things to a track but never nothing.

  10. Janet - June 27, 2017

    This is fantastic! I’m trying to make high-quality videos and the noise from my computer fan was adding some really unprofessional sounding noise. The other day I was going nuts trying to learn what settings to change on my microphone and wondering if I needed to buy a software program. This did a great job of getting rid of that noise and I already had it on my PC. Thanks very much for this!

  11. Allison Sheridan - June 27, 2017

    Glad this helped, Janet! I have to say, after you go through this one time, you learn to find ways to stop the noise in the first place. I used to have lots of fan noise from a laptop and I just started keeping it on a cooling gel pack so it wouldn’t fire up the fans so badly. As it aged I had to use icepacks wrapped in towels. Finally I cleaned out the vents and the fans went back to normal. All way easier than removing noise after the fact.

  12. Neil Hocking - June 28, 2017

    Thank you Allison

    This was really easy to follow and works great – at least it would have done if my emergency phone video wasn’t so bad to be beyond repair. Will definitely be remembering this for future audio though.

    Neil

  13. Travis - July 5, 2017

    We have a pesky neighbor that lets her dogs bark continuously and we’re getting recordings of it for a court thing but in the background you can hear her talk and say stuff about us. However, we have a lot of white noise(static) that I’m trying to remove so we can hear what she’s saying. I’ve tried numerous things but it ends up getting distorted. I’ve read that a lot of people use the noise removal tool but I only have noise reduction. I’ve checked the add-ons tool bar and everything is enabled. I don’t have a noise removal tool. Any help would be greatly appreciated. Thanks.

  14. Allison Sheridan - July 5, 2017

    Travis- The only thing I know that can help is to teach Audacity what the noise sounds like by giving it a good sample of only that noise. Do you have a reasonable length of pure noise? Under the best of circumstances, you always get some distortion.
    .
    I don’t know much about rules of evidence but it’s possible processing this audio might make it problematic to use.

  15. Lisa Krouze - July 6, 2017

    After I did the noise reduction the track is so quiet I had to turn my speakers all the way up and I still could barely hear it. Is there another step I’m missing?

  16. Rohini - July 7, 2017

    I have done exactly as told but with noise reduction but nothing happened, rather the vocal voice has reduced.
    Am I doing something wrong?

  17. Linda - July 14, 2017

    When I select OK to reduce the noise, my sound waves for the entire recording disappear. I can still play the recording back, but I am unable to do any editing because I cannot see the sound waves. Stumped Newbie.

  18. JC - July 26, 2017

    I tried this out a few times, and the audio kept coming out a bit “Tinny” after reduction. What should I do?

  19. Allison Sheridan - July 26, 2017

    I’m afraid with noise removal, tinny is the usual side effect. You can back off on the settings but you’ll always be trading off noise for tinny. Best solution overall (for the future) is to ensure you don’t have noise going into the recording in the first place.

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