If you are like me and you are looking to capture a crisp and clear sound on Camstudio while recording an on screen game with commentary, you could do so very easily.

Record sounds with Camstudio is very easy. Follow these four simple steps:
1) Launch the Camstudio application from your Desktop or Start menu.

2) Click “Options” at the top of the screen. (Choose your audio source (speakers/microphones),
go to ‘Audio Options’ and make sure the Audio Capture Device is set to the proper input.

3) Select “Record audio from microphone”.

4) Click the large red “Record” button above the viewing window to start recording your audio.

Voila!