Two questions about DBT.

[bturk667]

You know, the kind that the cable skeptics always write about.
1. When the DBT is being administered - by qualified people - is the system and room being used in the test, known or unknown to the test subjects?
2. Is the music being used, during the testing, also known or unknown to the test subjects?

Just curious.

[skeptic]

Generally they would not be told anything. Is the selection important? Very much so. Cable advocates, at least those you might take seriously if you were inclined to consider their arguements, claim that only high resolution sound systems can reveal the differences between one cable and another. Therefore, to prove whether or not the cable differences are audible you would want to start with equipment that would give the best chance for giving a positive result. They could also easily and credibly argue that some music is much more likely to reveal these differences than others. Perhaps music with great dynamic or frequency range. And of course, you want to select the candidates most likely to hear a difference, those with excellent hearing and experienced listeners. In other words, a real and objective study to discover true knowledge does not mean sitting a few people in a room, trying out a few cables and not telling anyone which are which, and then tabulating to see if the results are statistically significant.

What would a professionally run study consist of? First of all, a DBT would be devised to find the most sensitive situation where there is the best chance of getting a positive result. The best available equipment, the most demanding music, the best listeners. If they cannot tell the difference, nobody else would be expected to either. If they can, then it has to be determined what changes in the test would give a negative result. Lesser equipment, less demanding music, people with poorer hearing or without any ear training or listening experience.

Suppose the results revealed that only 15 % of the population could hear a difference, and only when listening to certain kinds of classical music, only on sound systems whose performance makes them cost $10,000 or more, and then only if they listen intensely. Then it would be stupid for 99% of the people who own audio systems to buy them. On the other hand, if it turned out that 85% of the population could hear a difference, that it is audible with any type of music and on any sound sytem costing over $1000, and that even casual listeners could hear a difference, then anyone should consider buying them. We do not have this knowledge today because those with a vested interest in selling this product have no desire or need to find it out. All it could potentially do is reduce their sales and profits. There are enough customers who so worried about being wrong that they are ready to part with their money on unproven products, especially when someone else tells them to, even without any demonstrable evidence of their value.

[bturk667]

You didn't answer my questions.
Let me clarify my first question. Is the systems and rooms that of the test subjects, or are they completely different, i.e. foriegn to the test subjects. Different equipment, different room size and acoustics? A completly different listening enviroment?

[E-Stat]

Is the selection important? Very much so.

Amen. Zapped by Jitter would assert the only untrained folks listening to completely unfamiliar material should be used for expediency.

Cable advocates, at least those you might take seriously if you were inclined to consider their arguements, claim that only high resolution sound systems can reveal the differences between one cable and another. Therefore, to prove whether or not the cable differences are audible you would want to start with equipment that would give the best chance for giving a positive result. They could also easily and credibly argue that some music is much more likely to reveal these differences than others.

Yes, keep going.

What would a professionally run study consist of? First of all, a DBT would be devised to find the most sensitive situation where there is the best chance of getting a positive result. The best available equipment, the most demanding music, the best listeners. If they cannot tell the difference, nobody else would be expected to either.

I wonder why then that is never the case? I have yet to see a single test of any sort using that criteria that supports the "all wire sounds the same" assertion. Mtrycraft gave me a nice list, but none of the references that I could readily look up met that criteria and gave null results. The only one that did from Tag McLaren merely concluded that their $300 /meter IC sounded no different than a $300 / meter Nordost IC. I think that Mtry really didn't fully read the report as he obviously didn't with the supposed "Russell findings" given that Russell conducted no tests himself.

Suppose the results revealed that only 15 % of the population could hear a difference, and only when listening to certain kinds of classical music, only on sound systems whose performance makes them cost $10,000 or more, and then only if they listen intensely.Then it would be stupid for 99% of the people who own audio systems to buy them.

That is an entirely rational business conclusion for those who peddle gear to the mass market. It makes total sense from an overall marketing standpoint.

It does not, however, deny the fact that many folks can hear qualitative differences using better cables on better systems.

rw

[mtrycraft]

Simple. No one is interested in speniding the money on a known outcome of a null. Senseless.
The oines published have been with the doubting Thomasas who dare to show up on testing day. Many back out and chicken out of fear.
Why don't you set one up? After all, you seem to be making all sorts of claims for audibility, yet not a single cited reference to support any of the claims. Oh, references thaz stand up.

[FLZapped]

Amen. Zapped by Jitter would assert the only untrained folks listening to completely unfamiliar material should be used for expediency.


rw

You're misquoting. Only with the correct testing set-up to match. Yes it is expediant when you are doing multiple tests per day on multiple products, one needs a better mouse trap or nothing would ever get done.

-Bruce

[E-Stat]

You're misquoting.

Don't think so.

"While we're at it, I suppose you also think that it is okay for the participant to be familiar with the test material, that it won't introduce another bias..... "

http://java.audioasylum.com/cgi/m.pl...offee&session=

"All the tests I've participated in did not require training."

http://java.audioasylum.com/cgi/m.pl...offee&session=

Here is a summary of other pearls of wisdom regarding your notion of DBTs gleaned from other posts:

http://java.audioasylum.com/cgi/m.pl...at&r=&session=

rw

[FLZapped]

None of the stuff you quoted has anything to do with your original statement, beyond the statement of fact in what I have participated in.

Nice try, but you're still misquoting.

-Bruce

[okiemax]

You know, the kind that the cable skeptics always write about.
1. When the DBT is being administered - by qualified people - is the system and room being used in the test, known or unknown to the test subjects?
2. Is the music being used, during the testing, also known or unknown to the test subjects?

Just curious.

Most DBT studies I have seen don't give much background information, so I'm not sure about the answers to your questions. However, I would assume in group tests, not all subjects in the group would know the test room like they know their own listening room at home. As for the music in the test, some subjects probably would know it better than others, and it might be new to some.

[mtrycraft]

Most DBT studies I have seen don't give much background information, so I'm not sure about the answers to your questions. However, I would assume in group tests, not all subjects in the group would know the test room like they know their own listening room at home. As for the music in the test, some subjects probably would know it better than others, and it might be new to some.

Actuall they do. Most are in subjects home or at his audio store where he is so intimately familiar with the stuff. Most use their own music. There is no restriction on any of the two asked question. None of it has made a difference.
It is hard to get 'golden ears' to keep their promises to participate, to be home when promised.

[pctower]

It is hard to get 'golden ears' to keep their promises to participate, to be home when promised.

That's what I like - a man who never makes claims for which he does not have sound empirical data to support.

[mtrycraft]

That's what I like - a man who never makes claims for which he does not have sound empirical data to support.

Yep, you only have to ask the right person for all the good audio stories about golden ears promised DBT demontsrations just to be skipped out on you. Doesn't take too many.

[maxg]

I wonder if there has been any analysis of the effect of the stress of being tested has on one's hearing, or ability to distinguish sonic differences?

During any of the DBT's oft refered to, are measurements taken of testee's heart rate, andrenalin levels etc. I tend to find that I hear far more from my system when I am relaxed than when I am stressed.

[RobotCzar]

You know, the kind that the cable skeptics always write about.
1. When the DBT is being administered - by qualified people - is the system and room being used in the test, known or unknown to the test subjects?
2. Is the music being used, during the testing, also known or unknown to the test subjects?

Just curious.

I haven't read the responses of others so excuse any duplication. In my experience most blind testing would be done on unfamiliar systems in unfamiliar listening rooms. There are, however, reports of individuals being tested on their own equipment, in their own listening rooms, with music chosen by the subject as being the most "revealing" segments of their own collection. The people at home also can take as long as they want to listen and almost always confirm that they hear differences prior to the test.

Of course, when tested. they consistently fail to demonstrate that they can hear differences between cables or even electronics. Some very subtle factors ARE reqularly indentified in DBTs including subtle volume differences.

I did note that skeptic quotes highenders as referring to "high resolution" systems. The phrase only has meaning in terms of measureable quantitities: distortion and frequency response accuracy. Most reasonable systems (not including speakers) have trivial (non-audible) differences in these factors. Differences in the quality of the recordings consistently exceed any measurable differences in reasonable quality audio systems. High resolution is a mythical buzz word as used by the high end except in regard to speakers where significant differences in frequency response into a given room do exist.

[skeptic]

"High resolution is a mythical buzz word as used by the high end except in regard to speakers where significant differences in frequency response into a given room do exist."

I'm not going to debate whether or not one amplifier sounds different from another. However, the term high resolution like mid fi is a perjorative term which some snobish and frankly not well educated audiophiles use to distinguish the most expensive equipment from mass marketed equipment. What they don't know is that not only is their boutique manufactured onesy twosy equipment grossly overpriced because of huge markups and inefficient manufacturing methods, but that much of it doesn't even perform as well as some of the mass market products at a fraction of the price. What is high end or high resolution depends on who you talk to. One audiophile's high end product it another's overrated piece of junk. But objectively, much of is is old or even antiquated design sometimes carried through to rediculous extremes. But then again, some people will buy just about anything so why shouldn't someone steal their money. If they don't, someone else surely will.