Just want to make a phone call from my laptop with Google Voice. Currently I can start to place a call with GV and the other phone will ring, but nothing on either end can be heard. My laptop speaker and mic works fine for other purposes.

Within G-mail, on the menu bar (top right corner), click Settings (or the little gear icon) then on the next page, click the Chat tab. In your chat options you'll see drop down arrows to select microphone and speakers attached to your soundcard which you can select if you want to talk and listen without using your headset.