Listening to Audio In

[Orin]

Hi all,

I have something hooked into my audio in jack, which I hope is Line  
In; the same thing on windows. What is to hear what is coming out of  
my PS2. I've got cables from  my TV to have friends over or whatever  
to play and I also have a cable in my audio in jack to get the audio  
that comes from it going to the Mac.

However when I turn on my PS2, nothing seems to happen. Do I have to  
do something like on windows in the volume control?

Thanks.