So, this is a combination of 6 tests, and each has 3 variants of the answer. That's definitely not enough to make useful statistical conclusions about the abili

So, this is a combination of 6 tests, and each has 3 variants of the answer. That's definitely not enough to make useful statistical conclusions about the ability to detect bad 128kbps audio, simply because it is rare. Indeed, the probability of choosing all the best clips by chance is 0.13%, and the probability of never choosing the worst (also by chance) is 8.8%. Choosing almost all the best clips, with exactly one mistake, would have the probability of 1.6%, and choosing exactly one 128k mp3 has a 26% chance. Disclaimer: I have not actually performed the test.