The 128kbps MP3s are easy to distinguish - they sound like audio in a washing machine, going round and round. Listen to cymbals that instead of going CRASH go C

The 128kbps MP3s are easy to distinguish - they sound like audio in a washing machine, going round and round. Listen to cymbals that instead of going CRASH go CBBRASPHHHHHH with the ending being the giveaway. Snares are also affected as they won't have such high frequency peaks so lose their SNAP sound. Bass drums are also easy to pick out - if there isn't much bottom end then you know it has been compressed. The a cappella version sounds like she's got a throaty cold on the MP3s. The SSSSSes sound different on MP3s too - it ssssoundsss like they've got a lissssppppp with MP3s. You may find it easier to listen quietly because then your ears only pick up the highlights instead of getting fatigued with too much volume (where they will shut down after a while).