It really depends on the encoder and song; I think the vast majority of people would have a very hard time getting above-chance on an ABX test vs a properly encoded MP3 at 320kbps, but I would not discount specific instances where things fall over and it still introduces artifacts that you can learn to recognize. Lossy compression is, unfortunately, not predictable in this sense, so there are always corner cases (or even outright bugs in encoders).
Here's one result which lines up pretty much with what I'd expect - if you get lucky with very specific songs/styles, you can pick out a 320kbps mp3, just barely, with good playback hardware.
Here's one result which lines up pretty much with what I'd expect - if you get lucky with very specific songs/styles, you can pick out a 320kbps mp3, just barely, with good playback hardware.
https://www.head-fi.org/threads/abx-test-of-320kbps-vs-flac-...