ahhh but you were making the assumption that Charles was talking about the molecule O2 not the element O 😉 (which I will concede is the most logical conclusion).
I know this if off topic (the whole thread is anyway) but thought it was interesting because it demonstrates how pre-conceptions can lead to different interpretations. I could probably somewhat shakily make some comments about frames of reference as well, but I've had a couple of glasses of red, so I'm probably just rambling 😉
Tony.
I know this if off topic (the whole thread is anyway) but thought it was interesting because it demonstrates how pre-conceptions can lead to different interpretations. I could probably somewhat shakily make some comments about frames of reference as well, but I've had a couple of glasses of red, so I'm probably just rambling 😉
Tony.
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If we talk about the properties of a gas then we are talking about molecules. Atoms don't form gases, molecules do. In some cases a molecule might consist of just one atom, but it is still a molecule. O (if it exists anywhere), O2 and O3 are three different gases. If we are talking about smell then we are talking about temperatures and pressures which a human nose can cope with, so only O2 and O3 are possible. O2 is oxygen. O3 is ozone. The only assumption I made is that Charles and the encyclopedia he quoted were using words with their normal meaning. Without this, communication becomes rather difficult!
I'm not sure what point he was making, but I fear he may have picked a bad example to illustrate it.
I'm not sure what point he was making, but I fear he may have picked a bad example to illustrate it.
A thought occurred to me. What if some brave high end amplifier manufacturer said, "You know what? I design my equipment so that the power supply doesn't get upset if I use an ordinary IEC cord on the floor. The stability and output impedance are so excellent that the type of interconnect doesn't matter when you use it. The mechanical stability is so good, fancy dots, weights, and cups of water are unnecessary. So with all the money you save, you can afford my high price."
Really nice idea, but that would require that this manufacturer had figured out mechnism is the the underlying reason for the (maybe existing) differences.
And of course this idea assumes that there exists only one solution for every detail under all conditions.
@ janneman & bonsai,
it seems there was kind of a bias mechanism working while you´ve read my post. (expectation or confirmation bias i´s assume 🙂 )
I only tried to remind, that "i hear something" and "i don´t hear something" are basically in the same class of assertions.
Without a controlled listening test no one knows if the listener really hears something and without a controlled listening test no one knows if the listener doesn´t hear something only because he believes in the nonaudibility of a certain effect.
Assuming someone did what SY is proposing (and assuming that it hasn't already been done) how long would it take to convince people? When that Australian chap discovered heliobacter pylori it took a lot of effort and many years to convince people that bismuth plus antibiotics could cure stomach ulcers. This is because a whole industry made its money on the basis that there was no cure, so just keep taking the antacids.
But of course! Color me human 😉
I read your post again and I think I read it correct 1st time. They are in the same class of assertions, but one of them can be verified. You cannot devise a test to prove that there is no difference. You can have 1000 tests where no difference is heard, but still in test 1001 someone might hear a difference and prove there is one.
It only takes one positive test to prove that there is a difference.
jan didden
J.J. does not have a PHD! He decided that working at Bell Labs he would learn more than getting a PHD from Frank Q. He worked at Bell Labs and researched hearing to develop the issues and some of the algorithms. He was on the MP3 committee. He was seriously involved in the final product.
There was an ethics test that used to be popular. You are captain of a sinking boat and throwing a person overboard will save the rest... Choices, an unwed teen mother, a middle aged guy, a young male with a long arrest record, an old guy.... The answer is that everyone has value you may not see at the time. J.J.s father would have passed for the old guy before fatherhood!
On power cords, I have written a few times. The impedance of an AC line to the outlet is about equal to that of the cord itself! NFPA NEC suggest a resistance for a 20 amp outlet from the breaker panel to be a maximum of .3 ohms! To a 200 amp panel from the line transformer add another .03 ohms, to the pole transformer add even less. There is not only source resistance in a power system but also load resistance which drops the line impedance.
SY measured a 3' cord and got half the value I mentioned, so a ten foot cord might even have more loss!
Then there is the issue of noise filtering available from the cord itself.
10,000 stinkin' hours! My theory always was that when you hear better you might not notice it, but when you hear worse you should. So if your Radio Shack system has been your reference for 10,000 hours you probably won't hear differences.
If Charles doesn't like what he hears and searches through the variables until he gets to a wood block and changes that and then hears a difference, what does that mean about the other changes?
Now does it seem possible that he can hear the difference between a Myrtle spacer block and a Maple one? No it doesn't, but you know he says it has happened and I have no reason to not believe him. Of course he hasn't tried walnut so we can't be sure. (That is not sarcasm, Myrtle has some similarity to walnut where they both differ from Maple!)
There was an ethics test that used to be popular. You are captain of a sinking boat and throwing a person overboard will save the rest... Choices, an unwed teen mother, a middle aged guy, a young male with a long arrest record, an old guy.... The answer is that everyone has value you may not see at the time. J.J.s father would have passed for the old guy before fatherhood!
On power cords, I have written a few times. The impedance of an AC line to the outlet is about equal to that of the cord itself! NFPA NEC suggest a resistance for a 20 amp outlet from the breaker panel to be a maximum of .3 ohms! To a 200 amp panel from the line transformer add another .03 ohms, to the pole transformer add even less. There is not only source resistance in a power system but also load resistance which drops the line impedance.
SY measured a 3' cord and got half the value I mentioned, so a ten foot cord might even have more loss!
Then there is the issue of noise filtering available from the cord itself.
10,000 stinkin' hours! My theory always was that when you hear better you might not notice it, but when you hear worse you should. So if your Radio Shack system has been your reference for 10,000 hours you probably won't hear differences.
If Charles doesn't like what he hears and searches through the variables until he gets to a wood block and changes that and then hears a difference, what does that mean about the other changes?
Now does it seem possible that he can hear the difference between a Myrtle spacer block and a Maple one? No it doesn't, but you know he says it has happened and I have no reason to not believe him. Of course he hasn't tried walnut so we can't be sure. (That is not sarcasm, Myrtle has some similarity to walnut where they both differ from Maple!)
Yes I referenced only the result and had misread, and sorry my info on the "one" damping resistor is anecdotal (it actually came from John Atkinson second hand, my bad). Apparently Carver offered amplifiers with reduced damping via small resistors.
But then there's the result, did I make it up? Is there something you know that equivocates or qualifies it? It was suggested that the tube amplifier needed a day to stabilize, who knows I don't. What's non-objective in quoting a result in passing, experienced listeners couldn't tell the difference under their conditions. It can happen, so what?
I've opened up some of Carver's stuff. pretty scary.
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Of course you can´t, but you _can_ try to figure out if the listeners does not hear a certain effect due to a bias mechanism.
That needs a controlled test within the listener does not know what the reason for a (maybe existing) audible difference might be.
If the listener confirmes within the test (on other tasks) that he is a good detector but still does not hear a difference for the eut then the conclusion is probable true that it was not due to a bias effect.
Although that sounds reasonable in fact it is not. Nobody is willing to discard an established set of rules due to a single empirical event.
I agree SY ... I'm all for properly conducted blind testing. Of course, as a DIYer it's not convenient (or possible) for me to blind test everything, and the ears actually do work very well IMO. I find having the help of an objective listener (my dad) very helpful. He often points out things I've missed.
Yeah, I think a certain amount of skepticism is a good idea.
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if even one listener is able to positively discern something in a series of tests - preferably with several independent experimental designs to decrease the odds of poor implementation/execution - then it is highly likely the phenomena is above human perceptual discrimination limits
DBT tests can give false positives when the experimental setup includes clues correlated with the test variable - switching artifacts that identify channels, noise floor discrimination in between music/test signals
Replication by independent groups is the “Gold Standard” for experimental science
The “nocebo”/uncooprerative/biased subject pre convinced of “no differences” is controlled for with positive and negative controls in the experimental design - it is not a inherent flaw of DBT - you just agree beforehand that some minimum score on detecting differences believed to be audible by previous studies positive results is required to include a test subject's results
DBT tests can give false positives when the experimental setup includes clues correlated with the test variable - switching artifacts that identify channels, noise floor discrimination in between music/test signals
Replication by independent groups is the “Gold Standard” for experimental science
The “nocebo”/uncooprerative/biased subject pre convinced of “no differences” is controlled for with positive and negative controls in the experimental design - it is not a inherent flaw of DBT - you just agree beforehand that some minimum score on detecting differences believed to be audible by previous studies positive results is required to include a test subject's results
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Can you buy a bottle of atomic oxygen, or were you thinking of doing the smell test in low earth orbit? O2 is the normal stable form on the surface of the planet.MRupp said:
Ears DO work well, it's the brain end that needs the controls.
It's actually pretty easy to set up well-controlled tests IF what you're trying to do is get to the question, "Do *I* hear a difference here?" and not worry about other questions like, "Does anyone hear a difference?" or "How much difference does there have to be for X% of the population to hear some effect?" The latter two questions are very interesting if you're developing codecs or are trying to get broad, marketable results, but are indeed difficult. For someone designing a product who thinks that something may be important (and is honest enough to know that he's a human with a human brain and not some sort of Uebermensch) and wants to dig out cause and effect, the first question is not hard at all to answer- if you want the answer!
There's a lot of confusion and fuzzy thinking because the precise question to be answered is not made explicit, giving lots of room for people to make excuses and put some sort of black magic aura around the rather prosaic things they do. And as I said before, there are things worth testing blind (does the coupling capacitor material make an audible difference despite minimal measurable changes?) and things that aren't (e.g., is a 6dB droop in the top octave the reason I think this sounds dull?).
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