Audacity is a free, open source solution that is widely used in the podcasting world for its versatility and power. It is the closest thing in the open source world to Adobe Audition, a leading audio editing tool used by podcasters and broadcasters around the world to capture, edit, and render audio files.
Just because Audacity is free doesn’t mean it can’t greatly improve the way your audio sounds. Vocals especially can often appear raw, riddled with background noise, and in need of some enhancement to create that radio sound so many podcasters try to achieve.
In this article, we’ll go over some of the tools that can help take your raw audio and turn it into something a bit more professional sounding without taking hours of your time to do it. While there are dozens of tools available, and plenty of different solutions out there, these are some of my personal favorite features. This solution may not work for everyone, though it is a good starting off point for a beginner.
Noise removal is a process in which background noise is taken out of the audio file, leaving you with the audio you actually want to capture. It can be especially useful in situations where your microphone doesn’t have a steep dropoff, making it more sensitive to things such as your air conditioner, computer fans, or breathing going on around you.
The process of removing noise from your track is pretty simple. You’ll need to start by recording 5-10 seconds of audio before you begin speaking, allowing Audacity to capture just the ambient sounds of the room that you’d like to have removed from the track. Once that time has passed, just continue recording as you normally would.
When you’re finished, click and drag your mouse cursor over the empty space in your track created at the beginning of recording. Select just the area where you aren’t speaking. Next, go to Effect > Noise Removal… and click the Capture Noise Profile button. This will allow the program to capture that audio segment as a noise profile, letting it know what needs to be removed from the rest of the clip.
Once that is done, click and drag your cursor over the entire audio track, highlighting the content you want to filter. From there, go back to Effect > Noise Removal… and select OK. You can fine-tune the reduction process in this window first, though I recommend seeing what the program comes up with first. I’ve only had to tweak these settings once, and that was during a recording in a loud public area.
Just about any radio studio in the world has a compressor in the audio chain. A compressor can take bland audio and enhance it in a number of ways to make it sound punchier and more rich. It brings vocals out and brings that full dynamic radio sound many podcasters are after.
Audacity’s compressor is pretty impressive, and does a great job of enhancing audio. You can access this feature by highlighting the track (or space in the track) you wish to enhance and navigating to Effect > Compressor in the top menu.
You may want to adjust the noise floor and threshold until you come up with something that sounds great to you. This can further separate your audio from your background as it brings up sounds that cross the noise floor.
A lot of folks hit the amplifier first in an attempt to bring up volume, but a compressor may be all you need to turn flat or somewhat low audio into something a bit more full-bodied. Every setup is different, though this is worth trying first.
Hard Limiter, Normalize, and Amplify
No one likes overdriven audio, and occasionally you may need to utilize a hard limiter to avoid peaks that bring distortion and other qualities that can ruin an otherwise perfectly good recording. There are several more advanced ways of going about doing this, though the hard limiter will essentially give your audio track a haircut to avoid peaks.
This option can be a double-edged sword. If your audio is extremely hot, that haircut can make it sound terrible. You might be better off running the normalize to bring those peaks down before throwing a hard limiter on audio that crosses that threshold by any obvious degree.
Amplify is another way to drive audio up or down, though it can introduce its own problems such as amplifying or reducing important audio to the point where your other audio effects don’t accurately enhance the sound.
Normalize can cause problems when multiple tracks have an intentional variance in volume. Bringing the peaks of each track to the same level can cause similar sounds to blend and ruin any room effect you might be going for in your recording.
Generating silence can make it easy to remove breathing from your audio. I hate hearing breathing during an audio podcast, and I’ve tried everything from music beds to silence removal to get rid of it. No tool has quite done the job quite as well for me as Generate Silence.
All you need to do is highlight just the area in which you pause to take a breath and select Generate > Silence. A window will pop up with a start and end time for the silence. Your highlighted area should fill this in correctly so all you need to do is hit OK. This will replace that section of the track with silence.
Keep in mind that this will only work if you have nothing going on in the background. It’s an eerie nothing in the middle of background hiss and vocals otherwise, so use this feature sparingly.
There is an ongoing and long-standing debate between audiophiles and professionals as to what effect chain and/or order makes audio sound the best. Better is always relative, even in the world of audio production.
Here is a look at an audio track before and after a little processing using the above tools.
Bottom line, you should try different settings and effect orders out to see what gives you the sound you want. For me, I usually hit audio with noise reduction, compressor, and normalize in that order.
So, what about you? What are your favorite Audacity effects, and how do you use them?