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

34 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.

  20. Joshua Tanenbaum - July 27, 2017

    I’ve imported my track, but it won’t let me “Split Stereo Track”. There’s only one track that shows up when I import my track. Not 2. So this doesn’t work from the beginning for me. Help if you can. Thank you.

  21. podfeet - July 28, 2017

    Hey Joshua – it’s kind of hard to tell what’s going wrong without seeing your file.

  22. Anonymous - August 2, 2017

    IT was the best post for my problem…thnx

  23. Deb - August 7, 2017

    Hey Allison,

    Thank you so much. I did a simple podcast this evening, and I was trying to clean up my audio for background noise.

    I used your easy step by step method and wow, all done in few seconds. Actually, you brought smile on my face because you are good teacher – one who can make things easy for non-experts.

    I have shared the URL with you where I posted the podcast in my website, it is about guided meditation, anyways. Thank you again for your help!

    Take care,

    Deb

  24. podfeet - August 7, 2017

    You made my day, Deb! I love to do these tutorials and if it only helps one person it gives me motivation to keep doing them. Smiling right now.

  25. John Pacheco - August 8, 2017

    So I wonder if the people having trouble isolating a section of the track to ‘create a noise profile’ are attempting to do so while viewing their entire recording. Go to the ‘view’ button, ‘zoom in’, multiple times and you can easily find a “noise only” sample. Also I ‘noise removal’ and ‘noise reduction’ are the ~= same thing.

  26. Allison Sheridan - August 8, 2017

    Great point, John. I haven’t actually looked at the instructions for years since I originally wrote this. I just reread and I see that I did show selecting a small area, but you make it much more obvious what people should be doing. I’m afraid that if the segment is too short, it may not be able to get enough information to do a good job of reducing noise. Hopefully, your advice will help others.

  27. Deb Chowdhury - August 12, 2017

    Hey Allison,

    I must thank you because you made it so simple that’s the key, and the mark of a good teacher (I have said that before as well). Well, I just wanted to update you, because it might be helpful for people who are on tight budget like me doing pod-casting and visiting your site.

    The podcast is there now, sorry it took a little while to upload it to Libsyn (URL is on my previous comment).

    I used a cheap $20 tie-clip microphone, my Samsung S7 as the recorder, and Audacity. Off course your valuable tips to clean it up. I think the recording is of decent quality (bearing in mind I have a 6 year old, and we all know what 6 year old’s do).

    Thank you again, I do appreciate your work, and I will keep following you.

    Have a great day,

    Deb

  28. Allison Sheridan - August 12, 2017

    Thank you so much, Deb – big smiles on my face! I don’t see your URL though, I wonder if my spam watching stuff stripped it out of your post? I’d like to hear how it sounds. From reading you I’m guessing that your passion for your topic will make podcasting a real joy for you. When you’re ready to step up your game on microphones, I have some recommendations for some inexpensive options.

  29. Deb Chowdhury - August 12, 2017

    Hey Allison,

    Thank-you, good morning from beautiful Canada.

    This is the URL: https://www.meditation-for-sleep.com/guided-meditation-for-sleep/

    But, I can see the URL and it is working in my first comment though. If you click on my name it is there. Please delete this comment if necessary, it might unnecessarily spam your comments section. I wish you had nested comments.

    Well, yes I would love and appreciate your comments on Microphones. But, I do have a high quality Rode NT-1 but that needs setting up etc. (time-consuming).

    But with my phone, it is so much easier just plug in and record, and you can do it anywhere, so I was experimenting with things and also it is a cheap set-up.

    Would love your comments on the audio please or suggestions when you have time?

    Take care,

    Deb

  30. Allison Sheridan - August 12, 2017

    Your audio sounds fantastic! I can’t believe that’s from a cheap lavalier mic on your phone.

  31. Deb Chowdhury - August 12, 2017

    Thank you Allison, for checking it out. Well, it is surprising where we are going in terms of technology, moreover I did not not clean up everything, BTW I am an IT professional (Database – nothing to do with audio engineering), and my boss, Rob is a big fan of mobile technology, and Google platform etc., actually he got me into it, and I decided why not give it a try, now you’re such an experienced professional Allison, you feel it is good enough, so I feel it is worth it!! Take care.

  32. Fianna - August 22, 2017

    What do the numbers under “Noise Removal” do and what would adjusting them do?

  33. Anonymous - August 28, 2017

    tried it and it made the tape hiss worse as well as the audio quality.

  34. podfeet - August 28, 2017

    That’s a shame. If you don’t have a spot where there’s just the hiss, it’s hard for Audacity to figure out what is hiss and what is good audio to keep. The best thing to do is eliminate hiss and noise at the source _before_ recording. I suggest finding a way to monitor the recording as its being made so if noise starts coming in, you can stop and fix it. I ALWAYS do a test recording and listen to it before doing my final recordings. Even if I’ve recorded a few minutes earlier with the same setup, I check it again. It’s amazing how it changes when you’d swear you’d changed nothing.

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