[Tanked]

So I've been using a turtle beach headset for quite some time now. Never had a problem with it. Over the last couple days, my volume in TF 2 has gone down, and the folks I'm chatting with on Ventrilo are able to hear my system sounds, even though I'm wearing a headset.

What might cause this? Is my soundcard going, or may it be the headset?
I'm stumped, as I've checked a million forums, and tried everything I can think of, and I'm pretty decent with hardware.


Help/flames greatly appreciated.



Also dongs.