MIDI Audio Output ("not supported")

[SUPERNOVA]

Just recently while trying to run Age of Empires or Halo on my Macbook Pro a message pops up while trying to start the game saying, "sound could not be initialized..." It refers me to go into Applications then Audio Midi Setup and ensure my audio output is set at 44khz and 16 bit. But when I get as far as audio the audio output it says, "audio output not supported" in the field where I would expect to make this change. Any ideas how to fix this?

 

[SUPERNOVA]

MIDI audio output

this problem was solved after opening Garage Band and then closing it. seemed to reset the audio settings so all is well.