@amir_asr - hi there amir, thank you for your participation in audiogon, and your extensive replies. I have a question that is very important to me to ask, and I hope you will find my request in the sea of responses this thread has become. There is a pretty basic test I found on the internet, of listening ability based on two different digitally configured formats, one in a higher resolution. Here is the said link -
https://www.npr.org/sections/therecord/2015/06/02/411473508/how-well-can-you-hear-audio-quality
Thank you for kind words. I am not at all a fan of this kind of test. They are usually designed by people who want to get a "no, there is no difference" answer.
The proper way would tell you this is the high resolution file and CD one. Then you are presented with a randomized test to identify the samples against those two versions. What this does is enable you to go through a training phase where in sighted listening, you can work to learn the difference if they exist. Once there, then you can take the blinded version. Such training is highly important and part of any protocol for such tests such as international ITU standard BS1116:
"Methods for the subjective assessment of small impairments in audio systems"
"4.1 Familiarization or training phase
Prior to formal grading, subjects must be allowed to become thoroughly familiar with the test facilities, the test environment, the grading process, the grading scales and the methods of their use. Subjects should also become thoroughly familiar with the artefacts under study. For the most sensitive tests they should be exposed to all the material they will be grading later in the formal grading sessions. During familiarization or training, subjects should be preferably together in groups (say, consisting of three subjects), so that they can interact freely and discuss the artefacts they detect with each other."
The reason for this is that if there are any potentially audible issues, we want to find them. We don't disadvantage the listeners by throwing two samples and so "go." There is no way to get trained this way as you don't know which sample is which.
Now, if our goal is to challenge someone saying they can tell the difference between high-res and CD in their sleep, then sure, you can run this kind of test. But you better not run and declare there are no audible differences. There can very well be and you will be missing it in this type of testing.