[falcolas]

The position of the mic on your throat changes how it sounds. The further away from your throat, the better (more natural) the sound, but the more ambient noise you get because the signal is lower. If you're right over the throat, the noise issue goes away, but you lose the qualities of your voice that the mouth adds.

In general, you'll get better sound from something like an Antlion mic with its passive rejection from a built-in omnidirectional mic opposite the cardiod mic pointed at your mouth.