A lot of the tools that are available to record Skype conversations will produce a .mp3 file with a left and right audio channel – left for the host, right for the guest(s). This is both a good thing and a bad thing, at the same time.
When you have one channel for the host and one for the guest, it’s easier to mix the audio levels and edit things properly. But if you leave the left & right channels on the same audio track, then you end up with an odd sounding podcast episode. Having one person speak from the left and one from the right makes for a difficult to listen to audio file. Things sound odd – like people are too far away or hard to hear.
To correct this, you need to split the left and right stereo channels out of that one track and create 2 mono tracks.
Splitting The Track Using Audacity
After recording a Skype call, you will likely have a .mp3 file with one person on the left, and the other on the right. Open this .mp3 file in Audacity, and you’ll get something that looks like this:
Notice how the left track and right track don’t have the same audio signatures – this is because they are two different people speaking. If you want to level the volumes, cut any coughs or sneezes or anything like that, you’ll need each channel on it’s own track. You’ll also want to do this, so that you have both the host and guest coming out of both speakers in your headphones, when listening.
Fortunately, Audacity makes it super simple to do this. It’s 2 clicks. The first click is to open the drop down menu on the track, and the second click is the “Split Stereo to Mono” menu item.
Once you’ve done this, you’ll see that there are now two tracks in the audio project.
Each track is now mono, instead of stereo.
Split Stereo Track vs Split to Mono
Note that there are two options in the menu, here. You can either split the track as stereo tracks, or as two mono tracks. You generally want to split them to mono, as this fixes the actual issue of having the track playing out of only the left or right audio channel.
If you do split to stereo tracks, you’ll end up with the tracks still playing out of the left and right channels, respectively. Once the tracks are split, though, this problem can be fixed on each track individually. Using the same menu as before, choose “mono” from the list of options, instead of left or right:
Once you have selected “mono” for the individual track, it will play through both the left and right channels at the same time, as a monaural track.
Go Forth, And Edit!
With everything split in to multiple tracks, you can now level each track, edit out the coughs and noises, and generally make the audio better than what it was previously.
Also note that if you’re using a portable recording like a Zoom H4N or Roland R-05, you’ll end up with a similar .mp3 file output – two microphones, turning in to a single .mp3 with left and right channels. This technique for splitting the channels in to tracks works well for these portable recorder outputs, too. You’ll likely have a little more work to get pure / clean audio from each side, but it is at least, a good start.