At 500 Hz you can reliably hear pitch differences of 2.3125 Hz, which means you did better than approximately 81.4% of people who took our test!
Used my Audio-Technica AD2K - probably not the best choice for this particular test, as the frequency samples were directly in its "semi-murky" range, and I clicked through the answers pretty fast too. I didn't expect the test to be as tricky as it was and kinda "tuned out" my brain as the pitches started converging more. I also found it annoying that they only played each sample once, as I wasn't paying that much attention at first and once it got trickier, it became more of a memory test and less of a pitch test.
I also didn't expect that the so-called "pitches" weren't all exact musical pitches, like a pure B-flat, B-natural, B-sharp, etc. It started throwing my musically-trained brain off when the pitches became less than half-way towards a B-flat or -sharp. I'd bet this test would probably confuse a lot of musicians like it did to me for that reason.
I also got annoyed by the length of the test, which couldn't have helped either. By the time the pitches started sounding like the C-flat/C-natural range, I wanted the test to end already!
Edited by Asr - 11/5/12 at 10:33pm