Onkyo TX-NR807 AFV

First of all, I love my new Onkyo Tx-NR807 it has made my speakers sound better than I have ever heard them. I am running into a problem I hope I can overcome with the help of a few more brains after it.
I am searching for a way to play a different audio source than what is playing on the TV. Let me explain. I like to watch sports and play video games while not listening to the audio from those sources. I have an appleTV which I have installed XBMC on and use an iPhone app to control it remotely without needing to see the screen to select music. I would like to know of a way to play a video game while at the same time listening to the audio from my appleTV.
Anything?

Maybe I should have RTFM a little more thoroughly. If you set the receiver to the video input you want then change to an "audio only" input ex. CD, TAPE. the video will stay but the audio will change. Just in case anyone in my position runs into this. There's your answer.