I doubt it's the bit rate. It's probably the recording. You would need really good speakers and a good ear to tell the difference between a bit rate in the high 100's and 320.
I'd say it's nearly possible to tell a difference in anything above 256, and even lower than that should still yield high quality sound.
I'd say it's nearly possible to tell a difference in anything above 256, and even lower than that should still yield high quality sound.