If one is going to use the term 'scientific' then it does go both directions, otherwise there is nothing 'scientific' about it. And no, I don't think any one who doesn't hear a difference will gain audibility from a DBT, just the knowlege that what ever 'experiment' they performed is valid.
Again, I think you're not seeing the general gist of what I'm getting at. More people should be posting something along the lines of what
Pyrrho did when claims are made that nothing was heard, see his post above. That includes mentioning if they are going to do a test with their friends, that to do it properly. And I'll leave it at that.
Jack
I think you are missing the point of what double blind tests can show. If people, on hearing two things, say that they cannot hear a difference, it will make no difference whether they say this knowing which one they are hearing or not. And, of course, it will not prove that no one could possibly hear a difference, as some people do have better hearing than others (though, of course, no one has superhuman hearing). What a double blind test can show is that someone can actually hear a difference between two things. If they fail to distinguish between the two things, then, assuming the person has been honest, they cannot hear a difference under those circumstances. But such a test cannot show that no one can hear a difference. For that, one brings into the matter what people have demonstrated the ability to do in the past, and bases one's judgment on that.
These ideas apply to other matters. Suppose someone claims to be able to jump a 15' tall fence without the aid of any devices and without being on top of something that would make the jump really less than 15'. Since the world record for highest jump (at the moment I write this) is
8'1/2", one would immediately suppose that the claimant was wrong. Still, they could try to prove it if they wanted to. There would need to be appropriate witnessing of the event, of course, not just taking their word for it, or the word of some of their friends. But suppose I were to claim that I cannot jump over a 3' tall fence. If I were to try to show you by jumping and failing, this would not prove that I could not jump the 3' fence. The reason being, of course, that you cannot be certain that I really tried. If I did jump the 3' fence (with appropriate witnessing of the event), then that would prove that I can, or, more precisely, that I could at the moment that I jumped it. One proves one can do something directly, but only indirectly does one prove that one cannot do something. So it is not symmetrical, and it does not work both ways.
The same applies to other matters as well. Suppose we are interested in the question of whether there is life on Mars. First, of course, we would have to know what we are talking about with regard to what counts as being a life, etc. Then, we would need to look for it. If we find life there (without taking it there ourselves), then we have a proof of the matter. But to prove that there is no life on Mars is not quite the same. One looks for life, and one looks for the conditions of life. The conditions seem somewhat ambiguous, so we are likely to be reduced to looking for life, and the failure, after a diligent search, is regarded as a reason to believe that there is no life there. But, of course, it does not have the same sort of absoluteness as finding life, as, for example, life may exist below the surface of the planet 1 mile down, and not above. In which case, we would likely not find it for some time, if ever. If we alter our question to whether there is life on the Sun, then we can probably say, with a fair degree of certainty, that the conditions are such that no life could live there (it being so very hot), so we don't need to bother looking at all. Notice how there is quite a lack of symmetry in all of this.
