I'm having the same issue here!
It's I didn't install anything new, and the soundis always like voice cancelling is turned on (stereo voice removal).
I've set the DSP plugin to none and still having the problem, checked the Audio drivers (and reinstalled it) but I can't find why this is happening.
If I change change, in the equalizer to use just one channel (left or right), then I can hear the voice, but when stereo is being used, I can't hear the voice again.
I think I must have hit some stupid keyboard hotkey but I have no idea of which keys have I pressed...
Does anyone have any ideas?