After looking at the pinouts for the two connectors on wikipedia (sorry, too lazy to dig up actual standards and look at those, so I'll trust the masses on this one), it looks like there are no dedicated audio conductors, and the audio data is just sent along with the video over the TMDS channels. If this is really the case, it would seem that for any DVI-HDMI adapter to work properly, it *must* wind up passing HDMI's audio signals.

What I'm not clear on is why this doesn't screw up your picture if you connect an HDMI output to a DVI input on a display. I haven't a clue what format the data actually takes, but one could speculate that maybe there's some packetizing or headers or something that causes a DVI display to discard the audio bits because it doesn't what to do with them? Anyone with more in depth knowledge of HDMI standards, please correct me or back me up or explain...