The microphones on smartphones and other devices for recording voice recordings have taken an appreciable leap in quality in the last decade. Sometimes I’ll record a little demo with guitar and vocals on my smartphone when I’m away from my studio only to later think “this was really good… I wish I could do something about that air conditioner in the background.” With that in mind, I thought today I’d cover a few effective options for how to remove noise from voice recordings.
How to Remove Noise From Voice Recordings
The best way to remove noise from voice recordings is to pull them onto a computer with a DAW (digital audio workstation) or a sound editing program, even a free option like Audacity.
This is a great option for those who aren’t music makers or mixers and don’t have a DAW like my Ableton Live, Pro Tools, etc.
Whatever software you’re using, you’ll generally have access to three effective options for removing noise from your voice recordings.
Apply a Gate
The most practical, simplest solution is to remove the noise from your voice recordings with a noise gate.
A noise gate is a tool designed to remove low level noise from audio, making it a great tool for removing all kinds of background bleed on a voice recording.
It does this by effectively silencing all the audio on whatever you apply it to unless that audio reaches a certain volume (threshold) at which point it opens up and allows the audio to pass through. Once the threshold is no longer met, it closes up again.
I did an entire tutorial on the best noise gate settings on vocals and those settings are actually very effective on removing noise from voice recordings:
Let’s briefly cover each parameter to explain why I recommend setting them where I do to get the best results in removing noise from voice recordings. Note that this is taken from FabFilter Pro-G, but these same settings will work with whatever gate you’re using.
Threshold
I just covered the threshold in how it is the main parameter on a noise gate. Where you set this determines how much noise and/or the desired audio of the voice recordings gets through.
I like to recommend setting this to the quietest practical point of the voice recording which typically turns out to be the quietest breath. This ensures that you’re not “cutting” out any of the desired out and only silencing the recording when you’re not speaking.
Floor/Ratio
Some noise gates label this parameter as the floor, others the ratio. Essentially it’s determining how aggressive the attenuation is on the audio caught by the threshold.
Setting the floor to -inf dB (infinite) or the ratio to max will effectively do the same thing – completely silence audio which doesn’t meet the threshold.
If you want a slightly more subtle and transparent effect where it’s just attenuating or quieting down background noise without removing it completely, dial this back a bit to taste.
While you may want to remove background noise altogether, leaving a little bit in will make the gate opening and closing and the effect overall sound more natural.
Attack
The attack determines how fast the gate closes once the threshold is met. Setting this to its lowest/instant point can create a snapping sound when the gate engages.
1-3ms is enough of an “on-ramp” for the gate to engage without necessarily hearing it, especially when you couple it with non-maxed out floor/ratio.
Release and Hold
Just like on a compressor, hold creates a set amount of buffer time after the threshold is no longer met before the gate begins to close back up again.
If the attack is the on-ramp, the release is the off-ramp, so this is the time it takes for that gate to close again after the threshold is no longer met.
Just like with the attack, setting the release to its instant position will create an audio artifact as you’ll be able to hear the gate abruptly closing.
A 25ms hold with a 100-300ms release is a great starting point on a gate for removing noise on voice recordings is a subtle if not conservative way to back off that gate.
I recommend starting there, then dropping that release to 50ms. If you don’t hear any artifacts like a pop or pumping sound, you might try backing it up to 25ms.
A gate will work in some situations, but it doesn’t solve the problem of cleaning up the desired audio itself. For that, let’s move to the next two solutions.
Use Audacity’s Noise Reduction Tool
Audacity is a free audio editing software and a very popular one at that which has been around for decades.
While it doesn’t have the depth that more powerful DAWs have, it does have a stock noise reduction tool which analyzes audio to filter out the noise you don’t want and preserve the audio you do.
I did an entire tutorial on this for how to remove background noise from a video, but you simply open Audacity and drag and drop your voice recording file into the program.
First, select a stretch of audio on the timeline of your voice recording in which there’s no dialog, music, etc. (no desired audio).
You want to click and drag to select a highlight of time on the timeline which is EXCLUSIVELY the noise you want to remove.
Now with that highlighted, in the menu section at the top of the program, click “Effect”, go down to “Noise Removal and Repair”, and click “Noise Reduction” from that bank of options.
This will bring up a window which looks like this:
With that noise still highlighted, click “Get Noise Profile” and it will close this window while it quickly identifies the type of noise you’re looking to remove.
This can be an air conditioner, computer fan, traffic, people talking in the background, any kind of ambient background noise.
Now open the “Noise Reduction” effect again and note that the three settings in “Step 2” will be applied to that type of noise you selected:
As I mentioned in the aforementioned tutorial on background noise removal for videos:
- “Noise Reduction” determines how much attenuation will be applied to the noise on your voice recording (in decibels).
- “Sensitivity” is how hard it targets the noise. Turning this to its max will begin to affect and attenuate the desired audio, so like all these parameters, you need to find the sweet spot for your specific audio.
- “Frequency Smoothing” takes it one step further and removes additional artifacts but, just like with sensitivity, it’s about finding the sweet spot.
Note that you can highlight a stretch of your voice recording with the desired audio and click “preview” hear it with the noise removal being applied.
If the background noise is still too prominent on your audio or you’re hearing artifacts from the tool, adjust the settings to be more or less aggressive, respectively, as necessary, and click preview again.
Now let’s look at one final tool which, like Audacity’s free “Noise Reduction” tool, can actually remove noise from on top of your desired audio, albeit much more effectively.
Use Waves Clarity
Waves Clarity Vx Pro is a premium plugin which is remarkably adept at differentiating between the audio you want to preserve and the noise you want to attenuate:
Unlike the last tool we covered, you don’t need to audition the noise to create a profile and tell the tool what you want to remove beforehand.
There is a very simple dial with “Ambience” on one side and “Voice” on the other.
Turning the dial all the way to the voice side instantly filters out any and all background noise and preserves the voice first and foremost, making this the single most effective tool at removing noise from voice recordings instantly.
While not strictly necessary, you can click “Advanced Controls” to expand the tool and adjust individual frequency bands separately, adjust the sensitivity, etc.
That said, it’s typically not necessary in getting clean audio from simply favoring “voice”. It’s not JUST about preserving the voice as it’s good at picking up what’s in the foreground of your audio and preserving that while removing the background, but it really shines on voices in particular.
There are three different ways or levels if you will of how to remove background noise from voice recordings so you can preserve and get the most out of your voice recordings like I have time and time again!
