Apple Logic Pro /LogicExpress Discussion

Hello all-
I am using Logic Express 7 on an old e-mac. I am getting a signal through my ART tube mp, and it shows up on the screen since I created an aggregate device thanks to someone's reply on here some months ago.

Now I am not able to monitor the microphone. Itunes plays through headphones, as do alerts. I have software monitoring selected. I don't know what else to do.

Any advice?

Thanks in advance--
Brian