>> twelve participants would be asked to come to Hanover.
It's a mistake to apply vanilla statistical thinking here. The 12 participants were not randomly drawn from the German population, they were extremely skewed towards enthusiasts/professionals: audio engineers, an owner of an actual Nautilus 801, someone who worked on MP3/AAC at Fraunhofer IIS, someone who works preparing masters for Deutsche Gramophon. If these are the people who have enormous difficulty distinguishing 256kbps MP3 from the CD original, I'm certainly not going to worry that I am going to miss out on anything with 256kbps MP3.
If 12 Grand Slam participants tell me they can't tell the difference between a standard $100 and a $1000 high end tennis racket, I'm not going to delude myself into thinking that it's going to make any difference for me.