How well can you hear audio quality?

Did this for fun in less than 10 minutes, using the computer output of my computer and my Grados. Marked all the 320kbps MP3 on the songs I didn’t know. The Vega one I got right at the first try with half the song played, yes I know my Suzanne.

This means that I wasn’t actually hearing the songs, with songs I actually know like the Vega one I can notice mp3 vs lossless because I know the song in it’s full. Anyone who takes this test for more than half hour and tries a second run just because got something wrong needs to chill a bit. Unless you got some really expensive gear.
I think I might need a DAC one of these days maybe that way I can find more correct ones. 

I could lie and say I got all of them or at least half of them correct. 
I didn’t lie because I already know I can’t notice high quality mp3 vs lossless in songs I don’t know. Thats also why I use mp3 in my portable player because I don’t notice the details in the street.

How Well Can You Hear Audio Quality?