I have a desk-top arrangement which was previously used with good success on Communicator, but is not workable with Lync. The arrangement is a seperate USB Microphone and generic PC speakers.
While this seperate mic and speaker worked as well as PolyCom or Chat speake/mic's on Communicator, it has a severe problem when used with Lync. The symptom is this... When the far-side of call goes quiet, I begin to hear white-noise from my speaker. The longer the far end is quiet, the louder the white-noise on my end. As soon as someone on the far end speaks up, the white-noise goes silent, only to build again when things go quiet on the far end.
If I switch to any of the integrated speaker/microphones, this problem is gone.
I have heard that one of my collegues has a similar problem with a particular headset.
I'm suspicious that this has something to do with Lync's "Comfort Noise" feature, but I can't find anything on the forums to support my suspicion.