In the device manager - when you don't have a components driver installed there is a big yellow exclamation mark - follow the exclamation marks to the device - I just checked and I can't figure out where you see which chipset it's using, but the name is usually enough - just google for that, and download the driver from the manufacturers site.
You could also run dxdiag and check there.
On unix it's lshw and then you pipe it through grep or something - both of which I would not expect to work on a mac because of apples babysitting policy.

Actually, I'd be interested in that - could someone run:
lshw | grep audio
on a mac command line and tell me if it does anything?