Use Audacity's Noise Gate To Improve Your Podcast's Audio Quality

If you want to create a great quality podcast, you need to have great audio. And to have great audio, you need to remove all the things that distract your listener, and make your audio sound less than professional; such as breaths and lip smacking. One of the easiest ways to do this is to use Audacity’s Noise Gate functionality. Come learn what it is and how to use it.

Over the last year and a bit as I’ve been creating podcasts and online courses, I’ve been rapidly learning about the ins and outs of great quality audio.

This isn’t to say that I have the best quality audio in the world, but I have been learning about how to continually improve it on a regular basis, using the wonderful tool that is Audacity. Now there are a whole range of aspects that create great quality, from high fidelity, to having the right noise level.

But one thing that I’ve found counts most of all, is removing the little things that distract the listener, and which contribute to a general unprofessional sound. To be more specific, what I’m talking about are the things that all of us do, such as breathing, licking lips, and so on.

Let’s be honest, we all need to breath, and not all of us are trained at reticular breathing. And while we may know to not eat any sugary food before sitting down (or standing) to record a podcast, we may not always follow that advice religiously.

So if you’re like me, and aren’t a trained voice over expert, or a professional singer or radio announcer, I want to share with you what I’ve learned about removing these imperfections through using a noise gate.

If you’re not familiar with a noise gate, it does what the name implies. And that is, it creates a metaphoric gate and blocks out any sound (or noise if you will) below a certain level.

Honestly, it’s conceptually that simple. The trick is determining the level below which to apply the gate. Gladly, Audacity, the excellent, free, and open source software, makes it relatively straight-forward.

Here’s how to do it.

Opening an audio file in Audacity

Open the recording in Audacity (if you’ve already recorded it) or make a new recording. Then, on the far left-hand side of the recorded track (labeled “Audio Track” by default), click the down arrow.

About a third of the way down, click the “Waveform (dB)” menu item, where you’ll see the audio’s waveform become much larger and more fine-grained.

Viewing a track as a waveform db in Audacity

After that, you need to enlarge the track’s size, by moving your mouse over bottom edge of the track, where you’ll see it become a double-headed arrow, allowing you to click and drag the track’s size, enlarging it.

With that done, play the recording up until you hear yourself taking a breath. When you hear it, make a note of, approximately, the noise level where it begins. In the screenshot below, you can see that its loudest level is -45 dB.

Finding a maximum volume level for applying Audacity’s Noise Gate

With that in hand, click the “Effects” menu, and then click “Noise Gate”, which opens the noise gate window. In that window, you’ll see a number of options and drop-down lists, but the two you need to focus on are “Level reduction” and “Gate threshold”.

Gate threshold is the threshold above which the noise (or sound) should be removed. In that field, enter the value which you found when you analysed the sound of your breath. Then click OK.

Applying Audacity’s Noise Gate

Depending on the size of your recording, this could take a few seconds and be barely noticeable, or it could take several minutes. Regardless, when it’s finished, have a listen to your recording again and you should be pleasantly surprised at how much better, how much more professional it sounds.

Now, it’s not going to be perfect. If you want perfection, you’d best pay a professional sound/audio engineer. But if you’re simply wanting to improve the quality of your recording, then you’ve just come a long way.

And That’s It

And now you’ve learned how to use a Noise Gate in Audacity to clean up your podcast vocals. By using this functionality, you can improve the quality of your audio, removing the minor — but noticeable — imperfections that detract from the quality of your recording.

It won’t turn it into a perfect recording, but it will help to notably improve its quality. Remember though, this is just the first step. So why not learn how to improve the quality of your audio — even further?

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