I have been using Microsoft Office Communicator and/or Lync daily for over a year now with my MacBook Air 2012 (2Ghz/8GB RAM/512GB SSD) without noticeable issues. Since I upgraded to the MacBook Air 2013 (1.7GB/8GB RAM/512GB SSD), I have noticed problems with audio quality issues with Apple's headphones and with USB headphones. In both cases, other callers notice an echo when they are talking to me. USB headphone audio also breaks up more than usual.
I am testing the two machines side by side and only the 2013 model exhibits the behavior. I am allocating 50% of available memory to the VM in both cases. I checked both to ensure that only the headphones audio input/output was enabled during testing. Both machines are running 10.8.4 and Fusion 5.0.2. The MacBook Air 2013 is also running the recent MBA 2013 Software Update 1.0 which fixes display flickering in Photoshop and in Vmware.
Has anyone else seen this behavior?