@Mr-Limp-Dick said in Static Noise:

i had a line in so i could play animal crossing on one display and have sounds for both on my ears. disabling the line in fixed it.

Thats exactly my setup too.

A feature i always missed in MW2 and now also in MW3 Plutonium was the option to set a different sensitivity for aiming down sights.
Maybe even 2 settable values for low zoom scopes and one for high zoom scopes.
If you could also set the transition timing like in bo4 or mw(2019) to instant, after zoom or even gradually, I would greatly appreciate it.

I had the same problem. MW3 is setting all microphone volumes to 100% on startup and i had the option "Listen to this device" enabled for one of them. So disabling this option or reducing the volume again, silences the noise.