We ran into some trouble recording episode 7 and had to re-record Anna’s narration. The problem stemmed from my attempts to even out the sound levels by using compression. Uneven sound levels is a pretty big concern with this podcast because an audio track can’t be any louder than it’s one point that reaches 0 decibels (the point before distortion). So even if the majority of the track is very quiet, if one point peaks as 0 dB, we can’t really raise the volume on the rest of it without causing distortion. And even if we do accept distortion at that one peaking moment, when we raise the volume on the whole track we raise all the background noise, too. So, ideally, the input signal should be very even and very loud so as to keep the levels at the same volume without distortion and to maintain a high signal-to-noise ratio.  A common tool to even out the levels is compression, so we tried using it on Anna’s narration in episode 7.

The thing about compression, though, is that while it squishes the loudest part of the signal closer to the average level, it also brings the lowest part up. When we set Anna up to read the narration the levels on the recorder weren’t as high as they should have been. When I sat down to edit the narration, I foudn that the noise-boost inherent in the compression compounded by the low signal-noise ratio resulting from us setting the input gain ineffectively made too much noise for the recording to be usable.  So we recorded it again more carefully and without compression and got a usable file.

Clearly, the input gain was a huge problem on that first recording, but I’m not sure that was the only thing. I’m suspicious that maybe the compression in the Flash recorder we use maybe isn’t tuned for spoken-word sure. There are no parameters to adjust, it’s either on or its off. I know that many podcasters use outboard compressors with great success. But I also know that making an expensive comp worhtwhile requires a room with some acoustic integrity, which we lack.

In any case, the more we do this, the more I’ve found that simplicity makes things easier. The first time we set up to record narration I hung blankets on the wall in a small room, rigged a condenser mic into a preamp and sonic maximizer before hitting the USB interface for recording on a laptop. The result was a mess, there were just too many things going on. Now Anna just reads into the same rig we do all the field interviews with. It’s easier, faster, and more reliable.