Originally Posted by FMW
When bias is removed, we all do or do not hear audible differences exactly the same way. We don't get different results from different people. What is audible to one person is audible to another. What is not audible is not.
That is not true at all. Take the dolby test chart I just post:
Look at subject 1 and compare it to subject 9. The subject 1's median detection level was nearly 200 nsec whereas subject 9's was 40 nsec. A difference of 5:1. And this is after Dolby screened out the people who couldn't hear the control test: "At the end of the training session, any subjects that exhibited unusual difficulty in hearing the effects of jitter were excused from final testing."
So clearly in Dolby's test there were people who had even less sensitivity than the ones used in the above graph.
I have tested literally thousands of people in double blind tests and there are always people with much more critical listening ability. They are often used as expert listeners. Let's look at a sample double blind test of speakers:
The bottom line is for Harman's expert listeners. Compare their 2 score with with 6.5 of students in the top graph. Clearly the experts are hearing artifacts that the students are oblivious to.
Then there is the ability to train to hear artifacts. This is strongly recommended step to allow the person the best chance to hear the impairment. When it comes to non-linear distortions it matters a lot whether you are familiarized with what you re supposed to listen for. Again, the dolby test had a training phase. Unfortunately many so called DBTs lack these critical aspects. They lack a control to weed out the people who can't hear well and do not provide an opportunity for the listeners to learn what they are supposed to be tested for. Of course both of these factors inflate the ratings for the negative outcome. If you are going to test cables for example, first use a cable that does make a difference. Then test people with the cables you really want to test. Throw out the people who could not hear objective differences that were there.
Then there is the issue of hearing range. I used to be an expert listener when it came to compression impairments. I was king of the road in the company and could identify artifacts that almost no one could. But then we got a customer who was complaining about a high-frequency artifact that I absolutely could not hear. We examine the code and found the problem and fixed it and he was happy. But I could not hear it and nor could my development team. So we hired the guy as an expert listener
Now if I were testing linear problems that would be a lot easier. If I filter all the bass out of a track, everyone hears it. And if I don't filter it, then no one would. Similarly if I test an equipment against itself, then everyone would be confused as to any difference existing. But these are the extreme points in the spectrum and one has to have deep knowledge of what is being tested and how to determine their validity.
I agree. People should have what pleases them as long as no hardship is involved. Our purpose is not to prevent people from owning audio jewelry. It is simply to have them understand what it is.
Well, was the above understood or not? Where did the knowledge come from that said everyone hears non-linear distortions the same come from? It seems that we are expressing opinions here as strong facts without foundation. This is not an easily understood field. Casual understanding is fine for yourself but when it is stated as the "science" then it becomes problematic when it is so easily disputed with data in this very thread!
The problem lies in the industry and the audio press preying on hearing bias.
I don't know that they are preying but rather, believing the same as their readership. But you are right that a lot of what is written is imaginary and subject to considerable amount of bias. At the same time, a lot of what is being passed on from the objectivity camp is folklore and voodoo science. I have noted a number of them in this thread including this post. There is no replacement for years of industry experience and hands on knowledge here. You don't see layman arguing in a group of doctors about efficacy of some medication. Yet when it comes to audio, it seems anyone can read some forum posts and then become a forceful advocate. No amount of correcting them will get them to back off. They will simply move to the next thread "preying" on people who have not heard the big worlds they are using.
The problem in audio is that most people do not understand that so they are making their decision based on a false premise that is promulgated by those who sell it.
Exactly. The issue is that both camps fall victim to this. So many people like to think their $50 gear is good enough and walk around with inferiority complex relative to others buying more expensive things. Being males then get us into non-informative discussion of science where they say clearly things that are wrong: "it is all ones and zeros." Well, no, it is not. What is their reaction? Anger and frustration because faced with the real science, they don't know what to say.
Now from reading your posts I consider you more knowledgeable than many but clearly topics like this fall outside of one's domain of expertise.