How to Normalize Audio in Audacity
Audio normalization is the process of adjusting the level or volume of your audio files without affecting their dynamic range (the relationship between the louder and softer points of the track.)
Normalizing your tracks is also one of the key elements to creating an episode that is enjoyable to listen to, and a quick way to make your podcast sound more professional. Fortunately, applying this effect isn't complicated, but how do you know when it's necessary?
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When do you need to normalize your audio?
There are two main reasons you'd want to normalize your audio files, and both situations arise in nearly every podcast edit.
#1. To match the volume levels across different clips
Let's say you have an intro music segment, a narrated segment, and an interview section you want to all be at the same volume level. You can use the Normalize tool to make sure one is not too loud or soft. The last thing you want is to record a voiceover that's way louder than the clip that comes after it, or vice versa.
#2. To make the original file louder
The other reason you would normalize audio is that your audio recording isn't loud enough. If the volume is too low, you might not even see the waveforms or hear the content, making editing pretty close to impossible. Amplifying your audio quickly fixes all these problems!
Now that you understand the situations in which you'd need to normalize your audio, let's look at the different normalization components and how to add the effect within Audacity.
Applying audio normalization
So here we have a track we imported into the workspace. You can press Cmd + A or Control + A to select the track. You'll notice the track's color change in the background, so you know you've selected the entire thing. You can also select multiple tracks and normalize them all at the same peak level.
From there, go up to the Effect tab on the top of your screen and click Normalize. In this menu, Audacity will give you a couple of options.
Remove DC offset
The first option it gives you is to Remove DC offset and center on 0.0 vertically (don't worry, this isn't as complicated as it sounds.) Moving the DC just means making sure your waveform is on the 0.0 line. If the DC offset isn't on 0.0, it can distort your audio and not leave enough space for other effects.
If you go back to your track, you'll see the 0.0 mark, and you always want that to be in the middle. Checking this box is all you have to do to avoid offset.
Some new PCs might have a DC offset cancellation feature when you record from the device's built-in inputs. This detailed walkthrough can help you enable the setting in your version of Windows.
Pro tip: Because DC offset can throw off other aspects of editing, we suggest doing this step before applying amplitude to the track.
Normalize maximum amplitude
The second option is to normalize your peak amplitude to -1 dB — or whatever value you want. But keep in mind, it's important not to adjust amplitude before correcting DC offset! If you've already corrected your DC offset, you can move onto normalizing the amplitude between tracks.
This value is important because you don't want your track's loudest parts to be so loud that they extend beyond -1 dB. Extending past this boundary results in distortion and clipping, and even though you'll be able to hear the audio without a problem, it won't sound very good.
The level of -1 is purposefully just below maximum amplitude to leave a little headroom for effects and quality playback. To normalize lower amplitudes, enter a more negative value (like -2 dB.)
If you select multiple tracks and adjust the peak amplitude, the changes will apply across all selected audio.
Note: Amplify and Normalize are similar effects that can easily get confused. The most significant difference is that Normalizing helps remove the audio disparity between tracks, while amplification changes the volume level one or more tracks by the same amount.
Normalize stereo channels independently
Let's say you're using a Behringer mixer and mixing two microphones — one's recorded on the left side of the stereo mix, and one on the right side. You'd want to analyze both of these channels separately because you might be speaking in a different volume than your co-host or your guest throughout the dialog.
If that's the case, select the checkbox to normalize stereo channels independently and adjust the amplitude separately for each channel. If you aren't mixing two microphones, you can leave this box unchecked.
Helpful features & buttons
Before you apply a change to a stereo track, you can use the Preview button to listen to six seconds of the audio and before you make any final decisions. If you like what you hear, you can click the OK button to apply the normalize effect to the selected audio.
The Manage dropdown menu lets you adjust the Normalize tool presets, which are useful if you want to save settings that you frequently use and access them quickly later on. You can look over this presets walkthrough to get more familiar with the options!
More Audacity tutorials
Hopefully, this helped you understand how to use Audacity to normalize your audio, adjust loudness levels, and get the peak volume right so you can confidently work with your track, knowing it's going to sound high-quality.
Audacity is an excellent open-source audio editing tool, widely used by digital audio creators, and one of Buzzsprout's top software recommendations. These tutorials can help you get familiar with the workspace so you can confidently use Audacity to edit your own content!