A related exchange:

I need to record voice responses from my participants in 30 second intervals at 9 different occasions during the study. I found the setup for the voice recording in the DirectRT help manual, applied it, and it is recording perfectly. The only problem is that the QUALITY of the recordings is terrible. You can barely tell that a person is talking in the .wav file that is generated. I need coders to be able to listen to and code each audio file, so this is a problem. I have the "RT threshold" down at 1 (on the soundcheck option in DirectRT), and the microphone seems to be registering, it is just the .wav file that is very static-y and inaudible.
The professor that I am working with on this project suggested that I email you and see if you had any suggestions for improving the quality of the sound file. Any insight that you have to offer would be greatly appreciated!!
What version of DirectRT are you using (i.e., 200x.x.x)?

Thanks for getting back to me! I actually fixed my problem...the original mic i was using to record was faulty, so once i switched microphones, the sound quality was fine. Thanks!
Just curious, what kind of mic was your old one and your new one? Just in case anybody else has similar trouble in the future.

The old microphone was borrowed from a friend. It is a Sony electret condenser microphone (as you can probably tell, I am not an audio guru, so I have no idea what that means). It runs off of an internal battery.
The current microphone is a headset/microphone that plugs into the computer via the sound card (output) and the microphone (input) jacks in the back of the unit. It was purchased at a RadioShack. Hope that helps!