I hadn't watched or listened to FLOSS Weekly in a while and so I checked out FLOSS Weekly 240 which focused on a service called Auphonic.
Here's the one sentence summary: Auphonic fixes your crappy audio automatically and for free.
Try it yourself:
Audio Algorithms and my experiences
I created a new Production using the audio from one of my screencasts. I enabled “Noise and Hum Reduction” (see below) and submitted the production.
Afterwards I was pleased to find that (1) it only took about 10 seconds and (2) the audio sounded great. The irritating ambient hissing in the audio disappeared completely without compromising the sound of my voice.
Do check out the Floss Weekly 240 Episode. There's much more technical detail about what Auphonic is doing to make all this work automagically.