> A lot of people won't pick up on differences unless something is pretty off, even if they were intimately familiar with the audio beforehand. Some people are

> A lot of people won't pick up on differences unless something is pretty off, even if they were intimately familiar with the audio beforehand. Some people are barely able to tell the difference between one and the same piece of music being played to them first in stereo and then in mono. Well anyone that declares something is transparent without "to me" attached, based on only their own testing, is in the flippant "delusional" category. I'm talking about people that get the best listeners they can find to seek out differences, and combine their knowledge together while hunting for flaws. If they can't even find one or two people that can pick out a distortion, then that's a pretty trustworthy standard, even if that only gives you a 99.9th or 99.99th percentile listener. Are these people aware of the specific problem you're stating? Do they agree or disagree? > Applying a scientific method (e.g. PSNR or spectral analysis) But that kind of truth is far from what you actually want, a measurement of how imperfect the compression is to human ears. You can use a complicated mathematical model for how listening works, but you're stuck calibrating that model with humans, punting the problem up a level. Bulk semi-subjective data is the best foundation we can get our hands on.