Quote: Originally Posted by Kees de Visser Perhaps JJ can explain what he considers a listening test and how it's different from the Hydrogenaudio standpoint. I was somehow under the impression they were not that different. Including positive and negative controls, lots of training for the test as well as familiarity with the equipment and music, and equiment validation are the biggies. Test evaluation might be an issue, too. Many tests, including some of the MPEG tests and 1116 make assumptions that the entire population reacts the same to impairments. While basic masking is universal, what people dislike when they can hear something is NOT universal.