320 immediately throws out everything above 19.5khz and a perfect human ear is capable of 20khz listening. So it definitely has some effect. I just think that, if I were to have a series of random encoded songs switching between 320/FLAC even the best audio engineer with the best sound setup would not be able to correctly identify the encode type on the first listen. Maybe if they switch back in forth, or are extremely familiar with the source material to the point where they studied it for the test. But at that point its like, who cares. I don't sit and listen to music and analyze the frequencies, I listen to enjoy it. In which case, if I'm playing it back, I'd much rather enjoy metric ton more songs with 99.999% nearly indiscernible unless flipping back and forth audio playback, then significantly less with 100%.