micrphone output directly
 

I have installed several versions of linux over the last years, and all of them do the following:
When I connect a microphone to the soundcard (Sound Blaster Audigy), the sound that the microphone picks up is output via the speakers, causing disturbance. High tones, you know.

until recently I simply disconnected the microphone, as I did not have much use for it anyway. But now, I would like it to work properly (For usage with skype or other communication systems).

How can I mute the microphone from my speakers?