Rather than defaulting to channel 101, have the T key default to a TEST mode -- the player's vox played back to him. We could then just advise newbs to press the T key and talk instead of trying to instruct them to "press /, then type your gameid in the Channel V box, then press T to hear yourself". (Don't know anyone that uses channel 101 anyway.)
Once they verify that their vox is working, they can figure out how to change Channel V to something useful.
This would also be useful to veteran players who just want to check their vox when it seems that they are not being heard.