Note I retracted my proposal anyway, and also gregorio gave me more good reasons to do that, but for the record: I don't know. But re-reading my original post I see I was a bit unclear about one thing: I wrote "Then do a well set up double blind ABX test using those specific audio fragments" but I didn't mean to use only those, I just meant to include them in the set of audio fragments to be used in the ABX test. So the whole intended purpose of the sighted listening was just to create an additional chance to find "suspected differences". And again I stress the point that that was the only intended purpose of the sighted listening, and that by no means any final conclusions should be drawn from the sighted listening itself. Without confirmation in the controlled blind test the "suspected differences" can be thrown out of the window so to speak.