By Jason Snell

June 24, 2015 12:21 PM PT

Podcast nerdery: Wrong microphone, right microphone

Note: This story has not been updated for several years.

One of the reasons I promote Call Recorder as a tool for Mac podcasters is that it records what you hear on Skype. Whatever microphone is selected as an input in Skype, that’s the one Call Recorder records. So if I can hear you, and you sound good, and you’re using Call Recorder, you’re going to give me a recording of your microphone that sounds good.

When people don’t use Call Recorder, I often discover that while they sounded great on Skype—their fancy high-quality external microphone was selected as the input in Skype’s Audio/Video settings—they were accidentally recording their conversation using their computer’s built-in microphone.

It’s very sad. It means I have to choose with a local recording of a bad microphone or a Skype recording of a good microphone. The Skype recording is generally of pretty good quality, though I prefer a local recording because it doesn’t ever get weird Skype sound artifacts (common when someone has a dodgy Internet connection) and it’s an isolated version of the one person’s voice. A recording of a Skype conversation contains everyone in the conversation, and when they all talk at once there’s nothing you can do to pick them apart.

Anyway, this scenario happened this week. One of my guests accidentally recorded using their computer microphone rather than the good microphone we heard on Skype. So I was going to have to use the Skype recording, but I had local recordings of the other guests.

This is doable, and in fact what I have to do when someone’s local recording utterly fails. (The most recent episodes of Total Party Kill feature a recording failure, so when one person talks I have to delete everyone else’s voices and use the everyone-on-Skype track instead.)

But in this case, I did have a track from the person. It did record a voice, just not one at a quality I could use. To save the day (and my time), I cheated. Here’s what I did.

First, I had to trim the local recording so that it synced perfectly with my Skype reference track. Then I dropped both tracks into Logic and synced all the other local audio files with them, using the Skype track as a reference.

I use Logic’s Strip Silence feature to make noisy areas in a track visible, and remove all areas of a track that contain silence. Once I run the Strip Silence command, only areas containing noise remain on any given track.

In this case, I could use Strip Silence to my advantage. I ran Strip Silence on the local recording of the computer microphone, meaning that Logic was only using that track at times when that panelists was speaking. It was, essentially, a map of when that person talked and when they were silent.

If only I could use that set of Strip Silence-created audio blocks as a sort of audio mask (forgive me, that’s my Photoshop creeping in)? After all, when the panelist is taking, it’s going to be (mostly) just them talking in the Skype track, too.

So that’s what I did. I quit Logic, opened both the local recording and the Skype reference track in Sound Studio, copied the Skype reference track, and pasted it right over the local computer-microphone recording, replacing it entirely. Then I saved the file and quit Sound Studio.

When I opened Logic back up, it did yell at me—it looks like this file has changed!—but then continued on its way. In the place of the old local audio was now the audio from the Skype reference track, but only the moments when my panelist was talking.

At that point, I still had some work to do—stripping out coughs and microphone clicks that weren’t actual talking, removing other audio tracks when there truly was cross-talk, and the like—but it was clean-up work. And much less work than having to manually cut in the Skype track (and cut out all the other tracks) every time the panelist with the bad recording spoke.

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