For me it's incredibly easy to detect even a 320kbps MP3 because of various deficiencies especially in transients and high pitched cymbals and such noises. They

For me it's incredibly easy to detect even a 320kbps MP3 because of various deficiencies especially in transients and high pitched cymbals and such noises. They become muddy or just disappear altogether. Once you point this out to somebody and A to B the same music, on the same system for them, they will hear how sloppy MP3s sound too. I've NEVER met a person who couldn't be trained to tell the difference in a few minutes.