I can hear myself in my headphones (echo)

[FromBabylon]

Hi all,

I come here cause I have a serious problem with mumble. This appear on Windows (8.1) and OSX 10.09 but I don't have the problem with skype or team speak so i bet this is a mumble configuration problem. My friends don't have it either with Mumble on the same server

When I use the config assistant or when I'm chatting I can hear myself in the headphones. Some speak about "playback volume" but if I mute the mic obviously it will not work and nobody can hear me.

How to fix that ?

Thanks