While using any communication software in Windows virtual machine, like Lync 2013, Skype or any other, I can hear other participants clearly, but everybody that is on the meeting with me gets a terrible echo (as if their speaking is played through my speakers and then picked up by my microphone)
Echo cancellation works bad for virtual machine due increased delay in audio path (~4 times).
This is fundamental limitation (cost) of emulation and currently can't be fixed in virtual environment.
Please note that emulation delays will not let using the built-in Microphone in some apps, e.g. Lync.
These apps sound algorithm fails due to sound delays.
For this apps you should use the headphones connected to the virtual machine directly:
- Parallels Desktop menu bar: Devices > External Devices > check Headphones name