At virtual PC, select "Communicate", "Call Via Internet", "Start Internet Call", unmute mic. Clicking on TeamViewer shortcut, select "Audio Conf": Voice Input "Signal" green bar increases with mic input. "Mute" reduces green bar to zero. "Volume" doesn't change green bar.
In "Voice Over IP", muting or unmuting mic doesn't change green bar. IE, green bar moves normally even if mic is muted in "Voice Over IP".
No mic audio from virtual PC. But if "Computer Sound" is checked, able to hear virtual PC sounds and music at local PC.