VoIP - how to mute my own voice?
 

When I talk into my mic, I instantly hear my own voice from the headphones. While this is good for testing, it gets quite annoying when talking over VoIP. How can I mute my own voice? I could find such a feature neither in my mixer settings nor in my VoIP software (Linphone). I'm using Ubuntu 6.06.

Thx,
moo-cow