Thanks very much for the references. (Note that in the first link, the differences that the self-identified audiophiles were better at hearing were between 64 and 128 kbps MP3s, which is really very easy.)
I fully agree with you that hearing the difference between lossy and lossless audio is largely a matter a learning to identify compression artifacts, and that an average over lots of untrained people isn't a meaningful test of audibility thresholds for it. What that means to me is that if you want to test the audibility threshold of lossy MP3s for trained listeners, give trained listeners a DBT. You would first train them in a sighted test, tell them what to listen for, let them hear the difference (sighted) and play with different sections of the track at different compression levels - and then do a DBT to determine where the threshold actually lies. I've done exactly that myself, and it proved to me that blinding the test really is essential. It's -extremely- easy to fool yourself into thinking you can still hear the difference at some low level, only to discover that you cannot identify it blind. As for the second link, I read the study (CD redbook versus hi-res) Hartley is referring to when it was first published. That study didn't just take an average, it failed to find -anyone- that could distinguish (out of something like 600 subjects). And that I think addresses the other point - if there were really golden-eared audiophiles, they would do exceptionally well on such tests. One could easily identify them and collect more data just from them (using a DBT) until it was proven beyond any doubt that they could hear the difference. But that doesn't seem to happen. So you'll get no argument from me that DBTs can be used in a way that renders the results uninformative, or that some people sometimes draw unwarranted conclusions from them. But I think all that means is that proper blinding is only one of several ingredients to a valid test. -- opaqueice ------------------------------------------------------------------------ opaqueice's Profile: http://forums.slimdevices.com/member.php?userid=4234 View this thread: http://forums.slimdevices.com/showthread.php?t=82067 _______________________________________________ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
