Reeks
It's a steady high pitched whine. It's not a track that it does it on. I can open up blank project and still hear the eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee. It's not as loud as recorded material. It also came up when I go to the record panal in the control panal. Those are the only times I hear it. I don't know if it's some kind of weird feedback or what but it is ANNOYING. Oh yeah, Linear Phase, I've done all the asio4all.com stuff about 5 times. No go. My next stop will be to go ART support for help.
You could have a bum interface. I bought mine from sweetwater, didn't work, I sent it back, they sent me a replacement, I'm still not thrilled with it. I can't record guitar without massive feedback, although.. I haven't even bothered checking Sonar yet.. my conclusions are based on Reaper, Ableton, Guitar Rig and Amplitube stand alone's, and finally Renoise...
So, just fyi, I am stuck with an ART too, I think they are ok, and certainly not, "great devices." I most likely, will never purchase an ART anything again...
Certainly, I have to buy a new interface soon..