I can not hear *some* of the sounds but can hear other sounds just fine. The most notable missing sounds are voice (including the voice over for the starting movie) and the swish of my weapon when I swing it. Music, water falls and other abient sounds are fine.
In the Audio options there is a "Voice Playback Device" and "Voice Capture Device" but there is only one option for each so I don't think that is the problem, besides I am missing more than just voice. I used to use the swish of my ax as a quick sound level check when I had to make adjustments but that is now totally silent.