Nothing ruins a great video like background noise. No matter where it’s coming from, here is a reliable method for how to remove background noise from a video.
How to Remove Background Noise From a Video
The process for how to remove background noise from a video is essentially a three step process. You may be able to skip the first step depending on your setup, but let’s take each one, one by one.
Step 1 – Isolate Audio From Video
As I just mentioned, you may be able to skip this step depending on your setup. For instance, my video editing software is compatible with all of my audio cleanup plugins, so I can target the audio within the video editing software.
If that’s not the case, you can drop your video into whatever video editing software you have access to (DaVinci Resolve is a good and very popular free option) and export the audio as its own WAV or other format file.
The main thing is to be able to create a universally accepted audio format file out of the audio itself, like a WAV.
Step 2 – Target and Remove or Mitigate Noise
There are a few ways to remove the background noise from your video once you’ve got that audio isolated.
I recently did an overview on how to remove background noise in Audacity, a free audio editing software. This program has its own built in effect for removing background noise.
Simply download Audacity and open the software, drag your audio file on to the timeline, and go up to the “Effects” tab at the top of the software.
From there, select “Noise Reduction” which will bring up this pop up:
This “effect” works to remove background noise in your video by identifying what you consider to be background noise so that it can train itself to look for it.
We need to do this ourselves, so highlight a 3 second or so clip of purely noise, such as some wind blowing or background crowd noise in the video (as a couple of examples). Don’t include any of the audio you actually want in your video during this.
Whatever you want to remove or at least mitigate, that’s what you want to highlight by clicking on the timeline and dragging for the duration of one instance of that noise.
When you’ve got the background noise you want to remove, click “Get Noise Profile” from the top of the Noise Reduction pop up window.
This will close as Audacity learns what you consider noise and as such want to remove from the video.
Now bring that same effect up again via the “Effects” tab and adjust the three settings in that second step section of the window.
Here’s a very brief overview of what each of these parameters is affecting:
Noise Reduction
The “Noise Reduction” parameter itself determines how much it will mitigate the targeted audio/background noise, represented in decibels.
Sensitivity
The sensitivity will determine how hard it actually targets that noise, and while you might think you want this up all the way, it can begin to affect the neighboring/desired noise.
The “Preview” will allow you to hear whatever stretch you’re playing of your video’s audio on that timeline with the noise reduction in effect, so you can adjust these while you’re listening.
Frequency Smoothing
If you’re not getting the results you want from the noise reduction and sensitivity parameters, you can adjust this to remove additional artifacts.
Remember to use that preview button; when you click it, you can hear the noise mitigation happening in real time on the stretch of the timeline that you want.
Try playing a short stretch on the timeline where you’ve got an instance of desired audio that you want to keep where the background noise is on top of it when using the preview. If the background noise is still too prominent, adjust the settings and click preview again and rinse and repeat.
Note that removing background noise from a video isn’t an all or nothing approach – it’s more about mitigating or otherwise reducing the prominence of that noise rather than removing it altogether, especially depending on the severity of the background noise relative to the desired audio.
You can also go for a more effective solution like a plugin like Waves’ Clarity Pro which is very good for isolating voices in particular from background noise with minimal artifacts:
Of course Audacity is free and this is a premium option; if this is a one off video you want to clean up rather than someone who does a lot of video editing, this likely isn’t the way to go.
Noise Gate
Alternatively, you might also try a noise gate.
While the above mentioned “Noise Reduction” is about training Audacity in this case the kind of noise you want to remove from your video, a noise gate works well for simpler background noise fixes.
While this is taken from my overview on noise gates for vocals, it can work with a low threshold to remove low level background noise:
Audacity’s Noise Gate has the same settings; the main parameter is the threshold which determines what level the audio needs to be to open the gate and let that audio pass through.
In the case of how to remove background noise from a video, you’d simply set the threshold to just below the quietest instance of desired audio, so the quietest spoken word you want to pick up.
Everything else will be filtered out, and with the release and hold times listed above, the gate sounds relatively transparent so you won’t hear it opening or closing.
Step 3 – Replace Audio
Once you’ve got your audio touched up to taste or as best as you can, you simply swap it back in via your video editing software.
In a lot of video editors this can simply mean right clicking on the audio file on the timeline itself; selecting “Replace” or something to that effect, and selecting the new audio file to do a straight swap.
At that point it’s just about exporting the video with the new audio in place as a new video file.
All in all this is a short and relatively straightforward process for removing background noise in a video or at the very least mitigating it to the point that it can work for your purposes.
