Audacity is a great, free-of-charge audio editing software. In today’s tutorial, you will find out how to remove background noise.
It is probably the most common task for people recording voice-overs in not perfect conditions. I myself have got this problem as my PC is fairly noisy and even though I have a good microphone some noise is usually recorded. Nothing to worry about, thanks to Audacity useful function we can quickly remove it. Here are just 3 steps you need to take.
Removing background noise in Audacity
#1 Record background noise
First things first. You need to provide a sample of the background noise so the program could separate it from the recording. The easiest way to achieve that is to record ‘silence’. Basically, you record your voice over or other sounds and at the end of the recording, you do not immediately hit the stop button. Instead, you wait for a couple of seconds and continue recording. By doing so, you will record background noise.
Have a look at the screenshot below. You will see on the left voice recording and then, the recording of the silence. As you can see, it is not the silence, the line is not perfectly flat which means that the background noise has been recorded.
#2 Get the noise profile
Now we need to let the program know what is the noise by ‘Getting the noise profile’. Use your mouse to select the noise (do not select your voice recording, only the noise). Then from the top menu go to Effects/Noise Reduction. You should see this window:
As you can see, there are a few options available. Because I am not an expert, so I leave them alone and just hit Get Noise Profile button. But you can adjust some setting and see how the process worked out. There’s a risk that the noise reduction will be too aggressive and it will distort the voice itself. If this happens, you can always go back, change the settings again and improve things.
#3 Remove the background noise
So at this stage, the noise profile should be registered in Audacity and all we have to do is to delete the noise. Press Ctr+A (or Command+A on Mac) to select the whole recording. Go again to Effects/Noise Reduction. But this time press OK button to remove the background noise:
The uneven line with the noise should be flat now. Also, it is a good idea to listen to the recording to check if it is not distorted. If everything is fine, that is all, just trim the recording on the left to remove the silence. If you are unhappy with the results, press Ctr+Z (Command+Z on Mac) to undo removal of the noise. Go back to step 2, change the Noise profile setting and remove the noise again in step 3.
How to reduce or remove background noise in Audacity – video tutorial
If you prefer to see this tutorial in a video form, please have a look at the video tutorial I have just published on YouTube where I show each step::
That is all, I hope you have found this useful and will manage to improve your recordings. Please let me know in the comments below if you have any questions regarding noise removal in Audacity or similar topic and I will try to help.