Audion Input / Mic configuration problems

[Liebguckerle]

Hey there,

after installing Mumble and entering the "audio configuration" menu, i get a loud, metallic sound (nearly blows my ears out). I get that instantly, it comes and goes in waves of 3-5 seconds frequency, without me speaking or any other noises in the background. This sound remains, whether i choose the "standard input" or my "Logitech Webcam C170". Sounds a bit like noisy feedback on old microphones.

I am using a Logitech C170 Webcam for audio input, my webcam works fine in Teamspeak or with the Windows 8 audio recorder.

Any ideas on how to solve this? Wouldn't wanna mumble anyone with this sound coming off and hurting their ears.

Thank you in advance!