Bruce Abrams wrote in message ...


If you allow for the fact that sight *may* provide a bias that overrides
true differences than you must control for it, always. Failure to do so
leaves open the possibility that you may have been influenced by sighted
bias. There would simply be no way to know whether the listening results
were valid or bias influenced, and no amount of arm waving shouting "DON'T
TELL ME WHAT I HEARD" will change that fact. Bias controls are necessary
not because the biases always exist, but exactly because they may exist.

I would like you to explain how 'sighted bias' explains what I heard
in detail, not just in general. To claim 'you heard differences
because you expected to' is not an explanation at all. It does not
account for, for instance, the nature of the differences I heard
(dynamic compression, brightness, dullness, etc.). It is the same as
explaining fire by invoking 'phlogiston'. It 'explains' nothing.

"differences where very small. Perhaps expectation bias might have
clouded
an otherwise identical verdict. But it is hard to explain his other
descriptions as being based on expectation bias. As he has tried to point
out."

Even to have the expectation bias that amps often and routinely sound
different is to set the base from which one then might easily start to
assign differences of the kind he mentioned. It might even demand that
differences be distinguished, which I have often thought is the plight of
the "reviewer" for the hi fi rags who must fill up the page with something
with which to keep them reading each issue. His was but a restatement of
the untested assertion that unstructured testing reveals easily percieved
differences, it is a bit of the dog chasing it's tail. That critter can
be put on the straight again by doing the test, restatements of the
assertion notwithstanding.

chung wrote in message news:AVR0c.160762$uV3.709405@attbi_s51...
wrote:
"not knowing what's being played. In fact, I would expect Keller to have
had a better hearing acuity than most of us."

Ms. Keller was deaf blind.

Oops, didn't know that. So why would Mr. Scarpitti say that even she
could tell the difference? Hmmm...

Blind folk have the same hearing as everyone
else, they only use it differently and pay more attention to sounds in a
way sighted folk don't. In the case of testing audio gear, blind folk do
no better then do sighted folk. Blind folk do pay more close attention to
spacial clues based on sound reflection, which might mean they more easily
detect it in recorded music or know it is false if reverb etc. are used to
produce spatial information. They might be able to better comprehend the
space a recording was made in, or know if it is a multi layered pan pot
product.

Yes, this was a way of saying that even a blind and deaf person could
detect these diferences....

Stewart Pinkerton wrote in message news:vcL0c.95418$4o.117983@attbi_s52...
On Sun, 29 Feb 2004 19:32:27 GMT, lcw999 wrote:

Now, having said that, I am aware that some participants
of this forum...long since committing themselves to a
basic "...all sound the same..there is no difference..."
mindset..will pile into this somewhat humorous fray.

They will be very adamant in knowing what "you" can
and can't hear! The humor of that stance comes to
play when one can easily follow the logic that you
or I, nor anyone knows what another individual's
mental processes are doing to the interpretive
processes. This is unique to each individual.

The humour is however somewhat dissipated when you consider that what
is being said is analagous to my stating as an absolute fact that
*you* cannot run a mile in three minutes.

This is precisely what is at question: whether we can hear the
differences. You're simply begging the question.

The point of course is that no human can do this, in the same way that
there is *no* evidence that *any* human can tell apart two nominally
competent cables (i.e. not comparing 8AWG to 28AWG or other such
silliness).

Begging the question.

Perhaps, we have a group that missed their calling...
..neuro-research..or some study of the myriad of
variables in the mental processes on the analysis of
input from external sources.

Indeed so - and there has been a raft of research over the last
century into human hearing thresholds and acuity, all of which
supports the notion that 'wire is wire'.

Occam.....


So, I respect your hearing differences...no arrogance
here about what you do or do not hear. If one hears
cable or amplifier differences..so be it!

However, not one has been found who can do this when they don't *know*
what is connected, so your 'respect' is rather misplaced.

The simplest explanation to account for audible differences among
components is audible differences among components....the burden of
proof is therefore upon YOU, not me....and I am not satisfied with the
mere assertions you have presented so far...

Steven Sullivan wrote in message ...


If I gave you those 7 different amps to listen to -- the ones I
listened to 17 years ago -- and if you could not tell any of them them
apart, then your hearing is impaired. I cannot make it plainer.

I understand you perfectly. Do you understand the how you might
be fundamentally mistaken?

I suggest it is the other way around.


That is because no two sounded alike, and most sounded vastly
different. This conclusion was confirmed by a friend who also listened
to them, and heard the same things.

And the flaws in such reasoning have been pointed out to you
numerous times now. You have assumed what you should be *proving*.

There are no 'flaws' in this reasoning. It was an observation.

After going through these amps several times, I began to note which
ones had a particular sound, and that sound was consistent from one
trial to the next.

Well, yes, of course it was. But alas that doesn't mean that 'sound' was
real. A false positive effect of that nature is by no means
improbable.

Impossible, to be honest.


The point is, it is simply not worth my time to converse with those
who deny that such differences can be heard at all.

Then by all means, feel free to cease doing so. That's what killfiles
are for. I don't btw imagine my replies to you will penetrate your
resistance to scientific fact, which you've established firmly;
I post them for the putative reader who might be following along, perhaps
wanting to see the arguments on both sides.

'Scientific fact'? You call what you offer here as 'scientific fact'?
You sit there behind your computer and tell me what I can hear? I
doubt any scientist would approve of this methodology...

I wonder if there is an aural equivalent to color-blindness....

If you would like, go to an audio shop that carries used products of
this kind, and ask to take them home. Hook them up to a set of Stax
Lambdas through a transformer such as the SRD-7.

By themselves, these instructions do no describe a good comparative
listening trial of amplifiers.

Since I use the Stax headphones with the amplifier, it the ONLY test
that makes sense. I'm the one who has to live with my choice: not you.

On Mon, 01 Mar 2004 23:11:08 GMT, "Harry Lavo"
wrote:

"Stewart Pinkerton" wrote in message
news:vcL0c.95418$4o.117983@attbi_s52...
On Sun, 29 Feb 2004 19:32:27 GMT, lcw999 wrote:

Now, having said that, I am aware that some participants
of this forum...long since committing themselves to a
basic "...all sound the same..there is no difference..."
mindset..will pile into this somewhat humorous fray.

They will be very adamant in knowing what "you" can
and can't hear! The humor of that stance comes to
play when one can easily follow the logic that you
or I, nor anyone knows what another individual's
mental processes are doing to the interpretive
processes. This is unique to each individual.

The humour is however somewhat dissipated when you consider that what
is being said is analagous to my stating as an absolute fact that
*you* cannot run a mile in three minutes.

The point of course is that no human can do this, in the same way that
there is *no* evidence that *any* human can tell apart two nominally
competent cables (i.e. not comparing 8AWG to 28AWG or other such
silliness).

Gosh, Stewart, how long did it take you to test every human and every piece
of wire ever used by them, and then verifying "competency" tests on those
that might have sounded different, to prove you point.

I don't have to, since all existing evidence and all medical and
engineering knowledge, says that I am right about this. If *you* wish
to claim otherwise, then that is an extraordinary claim, and the
burden of proof is on *you*.

Or might this be,
just might it be, and assertion, a judgement, your considered opinon?

It's a considered opinion based on a *total* lack of evidence to
support the existence of 'cable sound'.

Naw, it surely is a "fact".

It surely is a good working premise - unless you can offer *any* shred
of evidence in rebuttal.

Perhaps, we have a group that missed their calling...
..neuro-research..or some study of the myriad of
variables in the mental processes on the analysis of
input from external sources.

Indeed so - and there has been a raft of research over the last
century into human hearing thresholds and acuity, all of which
supports the notion that 'wire is wire'.

Last I looked, this thread was about amplifiers and what Michael feels he
heard in comparing five of them.

Clearly, you didn't look at the thread title. Michael is claiming that
he can't possibly be mistaken in what he thinks he hears in sighted
tests, we are pointing out that it's not only possible, it's highly
likely.

So, I respect your hearing differences...no arrogance
here about what you do or do not hear. If one hears
cable or amplifier differences..so be it!

However, not one has been found who can do this when they don't *know*
what is connected, so your 'respect' is rather misplaced.

Gosh, Stewart, what happened to the *properly designed* and *nominally
competent* disclaimers? A few more opinions slipping into fact?

Merely brevity - the disclaimers still apply to amps, but may safely
be extended to *all* so-called 'audiophile' cable.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

"Harry Lavo" wrote in message
news:17V0c.436628$I06.4934600@attbi_s01...
"Bruce Abrams" wrote in message
...
*snip* quoted text

If you allow for the fact that sight *may* provide a bias that overrides
true differences than you must control for it, always. Failure to do so
leaves open the possibility that you may have been influenced by sighted
bias. There would simply be no way to know whether the listening
results
were valid or bias influenced, and no amount of arm waving shouting
"DON'T
TELL ME WHAT I HEARD" will change that fact. Bias controls are
necessary
not because the biases always exist, but exactly because they may exist.

The are not *NEEDED* for home audio purchases and comparisons as long as
the
person doing the comparison is willing to accept some risk. And
expectation bias as postulated has to be stretched to the extreme to cover
five amps with four different "sounds".

This is a specious argument, as no listening tests at all are *NEEDED* for
home audio purchases and comparisons as long as the purchaser is willing to
accept some risk. The bias inherent in sighted tests has been proven to
exist (and you, Harry, have acknowledged its existense in other threads).
The effect of such bias in a comparison of 5 or 7 or even 10 amps is no more
unusual than its effect in a 2 amp comparison.


This part of this thread started rather interestingly with Michael
asserting
that Occam's Razor suggested that the simplest explanation for people
claiming to hear amp and cable differences was that the differences exist.
Stewart and Steven both jumped in to claim that, no, Occam's Razor
suggested
expectation bias as the likely culprit. However, neither explained to
Michael what expectation bias was.

Surely you are aware that expectation and other sighted biases have been
explained to Michael many, many times in recent months, and each time that
they were Michael has responded the same way; namely to maintain that he is
uniquely immune to such biases.

*snip* for brevity

Michael's type of comparative test is one many audiophiles have done for
themselves at times..a shootout comparison. Not the most scientific.

There's nothing in such a comparison that is remotely scientific.

But
there is nothing in such a shootout to assign sound character to the amps,
as Michael points out. The worst expectation bias can do is to make one
assume differences exist.

A fairly significant point in attempting to establish a preference where
none might exist, wouldn't you say?

He has already said that for one pairing the
differences where very small.

But he decided that the differences were there none-the-less. I'm sure I'm
not the only one who found it particularly difficult to discern between two
cables, yet after many swaps decided that there were some very subtle
differences. The brain wants to hear such differences no matter how loudly
we protest to the contrary.

*snip*

And as I have tried to point out elsewhere, this "sighted bias" stuff is
often used in a negative way and without any real consideration given to
its
applicability. In my opinion, it is often overused here a s a "club" and
to
show off. Educating people is fine. Picking fights or debates with them
without even explaining your terms is not so terrific.

One of the purposes of this NG is education. When someone approaches with a
question regarding a cable suggestion, isn't it appropriate to suggest that
they conduct their listening test in a blind fashion to ensure that they
don't spend an extra $500 on cable when it would be far more effectively
spent on speakers?

For what it is worth, I am probably familiar with two of the amps he
tested
(by knowing the brand) and would agree with his characterization of the
sound if they were the amps I heard. Not that that is definitive in any
way, but it may mean these brands do have a characteristic sound and that
he
heard
them. Or perhaps we are just two small parts of a mass delusion.

The masses have been deluded regarding far weightier matters.

chung wrote in message news:AaL0c.95414$4o.117307@attbi_s52...

Michael, I and others have described similar tests here under similar
conditions, and have always been told we are just imagining the differences
based on "expectation bias". Expectant of what they can't say.

Unfortunately, some of the members of this forum, while intellectually
understanding it, have a difficult time differentiating between "sight *may*
provide a bias that overrides true differences" with "sight *always*
overrides true differences and makes your comparison invalid".

This is a misrepresentation of those members' position. What some of us
are saying is that you have to be cognizant of the effects of
expectation bias, and take proper steps to control it , if you really
want to find out if there are *audible only* differences. We always have
said that if the differences are big enough, like those between
speakers, then you don't really need DBT's to differentiate them. We
don't say that "sight always overrides true differences" (in fact we
argue if the audible difference exists in the first place), we are
saying that expectation bias is very likely to override subtle
differences, and that DBT is the best way to control for expectation
bias. In the case of competent amps and speakers, we know that those
differences should be subtle at best, from measurements like frequency
response, distortion and signal-to-noise ratio tests.

What am I 'expecting'? How can I 'expect' the Bryston to sound dull
and the PS Audio to sound bright, when I never heard them before? How
can I 'expect' them into sounding the same in repeated trials?

They should
know better, but they don't seem to be able to allow even the possibility
that there are real differences and that you might have heard them.

No, they do, that's why they recommend the Harry Lavo's and Michael
Scarpitti's of this newsgroup to do controlled tests to see if those
differences are real. Heck, they even throw in real money to motivate
them, in the case of cables.

The control of the test is valid. I connect A to Stax and listen. Then
I connect B to Stax and listen. Then I connect A again and listen.
Then I connect B again and listen. Then I connect C and listen,
etc....

Given that that is how we use amps, that is valid for testing
them...we hook them up and listen...

I took all these amps home because I did not know anything about them.
I had not been hanging around audio salons all that much to have
formed any opinions on any of them. The only one of which I had formed
any impression was the Harmon Kardon Citation, as I had read some of
their literature.

In Bruce Abrams writes:

"Michael Scarpitti" wrote in message
news:ebL0c.156130$jk2.596671@attbi_s53...
Bruce Abrams wrote in message
news:wUz0c.91281$4o.116016@attbi_s52...

*snip* quoted text
How could my 'expectation' have given wildly different, CONSISTENT
sound to each amp?

Because you made your judgement the first time you heard it and then
confirmed it to yourself each time you listened to each amp. When you
engage in the type of uncontrolled, sighted listening that you did with the
amps, you need ways of charecterizing the sound from each amp. Those very
characterizations presuppose that the amps will sound different, otherwise
you'd have exactly the same listening notes from each amp, and nobody really
wants to admit to themselves that they heard no differences.

Why did the Bryston sound rolled-off at the top?

Irrelevant why it did to you at the time. When you sat down to listen to
the Bryston you needed words to characterize the sound, as I mentioned
previously. The point is that once you thought it sound rolled-off, you
confirmed it to yourself each time by saying, "yup, there's that high
frequency roll-off again," hence the consistency of the result. If you
wouldn't have known which amp was playing the second time, you would have
been listening to characterize it again and not to confirm what you thought
you heard the first time, and chances are no better than random that you
would have characterized the Bryston the same the second time.

Yes, and the same problem exists when you listen to A or B in a DBT. That is,
you assign a "label" to the A sound and then to B sound in the same way
(i.e that A is "rolled off and that B is "bright") as you described above.
There is no difference if you know that the amp is "Harman" or "A".

So when you listen to X, you try to hear if it is "bright" or "rolled of".
Since this "sound labels" where constructed in your mind, you have to obtain
random results from this test, because neither A nor B nor X is bright/dull.

The problem is that the results are random and they are random INDEPENDENTLY
FROM ANY REAL DIFFERENCES between A and B, if any exists.

This invalidates the whole idea od the blind testing.
That is, the (correct) premise, that what we hear is influenced by not the sound
alone, invalidates the DBT testing method.

Piotr Wyrostek

"chung" wrote in message
news:h1S0c.95108$Xp.423683@attbi_s54...
Harry Lavo wrote:

This is a misrepresentation of those members' position. What some of us
are saying is that you have to be cognizant of the effects of
expectation bias, and take proper steps to control it , if you really
want to find out if there are *audible only* differences. We always
have
said that if the differences are big enough, like those between
speakers, then you don't really need DBT's to differentiate them. We
don't say that "sight always overrides true differences" (in fact we
argue if the audible difference exists in the first place), we are
saying that expectation bias is very likely to override subtle
differences, and that DBT is the best way to control for expectation
bias. In the case of competent amps and speakers, we know that those
differences should be subtle at best, from measurements like frequency
response, distortion and signal-to-noise ratio tests.


What you are saying above is a very reasonable position. Unfortunately,
it
seems to believed only in the abstract here. When somebody such as
Michael
comes on saying he can hear differences in amps...there is no
questioning
him on his listening conditions

Actually I asked him whether he level-matched...


You did late in the game, but that was not the initial concern of those who
responded.

, no consideration of the age or circuitry of
the amps in question (despite one being a digital amp...the one chosen
at
that). .no discussion of his stated purpose or state of mind. All that
happens is that he is told because he listened sighted, he is surely
imagining things.

He did describe his listening conditions. Maybe you have missed that?


Yes, and listening over stax headphones should probably have raised a few
cautionary red flags among the objectivists, since listening on a really
good set of headphones lets your hear things that ordinary speakers and
room reflections might obscure.

Then the turmoil ensues.

The turmoil ensues because he refused to believe that expectation bias
could lead to false positives when trying to detect differences. Now
please answer this: do you agree with Michael on this key point? Do you
believe that expectation bias should be controlled for?


I believe it should be if you are after scientific proof. Done with a
blind, monadic, evaluative test. I think it is a ridiculous burden to put
on an audiophile trying to decide for himself what to buy...and it is an
equally ridiculous thing to demand that he do before he dare discuss on this
newsgroup the sound of products as he heard them on a "kitchen table test".


They should
know better, but they don't seem to be able to allow even the
possibility
that there are real differences and that you might have heard them.

No, they do, that's why they recommend the Harry Lavo's and Michael
Scarpitti's of this newsgroup to do controlled tests to see if those
differences are real. Heck, they even throw in real money to motivate
them, in the case of cables.


Insisting on a test that the "testees" don' t believe is valid. Nice
'gotcha.

Now Harry, how does the word "recommend" become "insist"?


The insistance is that the test be a blind comparative a-b or a-b-x test
rather than a serial, modadic, evaluative test that happens to be blind.

As far as I am concerned, you don't have to do any controlled testing.
You can pick amps/cables based on whatever criteria. However, when you
want to convince others that there is real, audible, difference between
them, you should use controlled testing like DBT to make sure that
expectation bias (and other stuff like mismatched levels) does not
invalidate your listening tests. DBT is the standard methodology on
difference detection for such a long time, that I don't see any reason
why Michael would have problem with it.


He may not have a problem with it. Other than to consider it a waste of
time. But he certainly didn't expect to be told that he was wrong, wrong,
wrong to have thought he heard different sound characteristics from the amps
because he didn't do the test double blind. He might or might not have
heard such characteristics...he was given no benefit of the doubt.


So
don't get upset...it's a world view of theirs that you are not going
to
change.

All you need to change their world view is to pass the cable DBT test!
. Simple, isn't it?


Sure, would greatly simplify the objectivist world-view here if we would
just go away and stop challenging the test.

The funny thing is no one asked you to go away and stop challenging the
test. (In fact we even put up money hoping you would take the test.) And
you were the one who said that Michael should go away and find some
other topics to discuss...

Nobody asked him to go away. We just suggested he not tear himself apart
looking to convince you guys. It looks like he reached the same conclusion
on his own.

You yourself put the smiley in your statement, meaning you know it is a
ridiculous statement that won't be accepted. Why, because you are asking us
to "beat" a test that we think is flawed. Meanwhile, my efforts to point
out why I and others believe it is flawed and to propose a proper control
test have met with very little but stoney silence...as if the issue were
never raised. If something uncomfortable comes up, just ignore it, right?
The way to prove the test right or wrong is to devise the control test and
get on with executing it.

I say the best way to get to the other side of the fence is to open the
gate. You say the best way is to lower my head and keep charging the fence.
Which do you think has the best chance of getting us to the other side?

BTW, how would you know that Michael would fail a DBT on amps?


I don't know nor did I claim to know that he would. But like Mike Kueller,
I believe the test technique itself loads the test in favor of "no
difference". And I would never encourage him to undertake a loaded test.



But you can ignore them and instead focus on other topics of interest
here
on the forum.


I think the subjectivists actually find this topic of great interest,
based on how frequently they post in these threads...


You think the objectivists ever let an assertion of heard differences
pass
without comment or challenge?


You realize how many of these threads were started by subjectivists?


This one was started not once, but twice, by an objectivist.

"Harry Lavo" wrote"

....snips to content ....


I think the subjectivists actually find this topic of great interest,
based on how frequently they post in these threads...


You think the objectivists ever let an assertion of heard differences pass
without comment or challenge?

Try this:

I, Tom Nousaine, analyzed nearly 2 dozen published controlled listening tests
of power amplifiers that had been conducted to that time, of which only 2 (both
high-output impedance tubed amplifiers; one of which was authored by Arny
Krueger) had confirmed positives for audibility.

Prior and subsequent to that time I've personally confirmed that more than a
dozen amplifiers I've owned (or used) all sound exactly the same when operated
within their power limits (Heathkit (2), Parasound (3), Stewart (2) , Fidek,
Samson, Adcom, Bryston (4), B&K, SUMO, PASS and Yamaha) either to me or the
several dozens of subjects employed under listening bias controlled conditions;
even when conditions were maximally implemented to high-light possible
differences.

But whenever I mention any given experiment subjectivists never let that pass
without challenge.

"Michael Scarpitti" wrote in message
news:YDR0c.160642$uV3.708646@attbi_s51...

The point is, it is simply not worth my time to converse with those
who deny that such differences can be heard at all.

If you would like, go to an audio shop that carries used products of
this kind, and ask to take them home. Hook them up to a set of Stax
Lambdas through a transformer such as the SRD-7.

Then you will hear the differences.

I don't deny that you heard differences. What I want to know is how
you hooked up the headphones to the amplifiers?

Norm Strong

Bruce Abrams wrote in message ...
"Michael Scarpitti" wrote in message
news:YDR0c.160642$uV3.708646@attbi_s51...
*snip*
(snip)


After going through these amps several times, I began to note which
ones had a particular sound, and that sound was consistent from one
trial to the next.

And each time you listened to 'A' which you thought you found bright, you
reinforced that it did, in fact, sound bright.

Not so. I listened again, and confirmed that 'A' sounded bright AFTER
listening. I cannot make this any plainer.

Repeated trials confirmed initial impressions.


The point is, it is simply not worth my time to converse with those
who deny that such differences can be heard at all.

If you would like, go to an audio shop that carries used products of
this kind, and ask to take them home. Hook them up to a set of Stax
Lambdas through a transformer such as the SRD-7.

Then you will hear the differences.

I've already heard exactly such differences between cables, right up until I
realized I was hearing the attributes I'd ascribed to cable 'A', only I was
really listening to cable 'B'. Until you allow for the existence of sighted
bias, a phenomenon that is universally acknowledged to exist, you are
correct in that further conversation on the subject is meaningless.

How can 'bias' lead me to believe that two amps that I have never
heard before. know nothing about, and have no opinion of, sound
consistently different, that is, have consistent sonic characteristics
from one trial to another and that mark them as different from each
other? That is impossible, I put it to you.

I had formed no opinion of 'Hafler' sound or 'Harmon Kardon' sound or
'Denon' sound. I had no idea what to expect. The Harmon Kardon
Citation amp had the most impressive literature, and I expected this
one to be rather good-sounding. It was not. It was rather
disappointing, in fact among the very worst. The Denon was clearly
superior. I had no expectation that this would be the case.

The point is that I was judging only how they sounded. I did not allow
the sales literature to sway me.

wrote in message news:G5L0c.92162$Xp.418678@attbi_s54...
"Unfortunately, some of the members of this forum, while intellectually
understanding it, have a difficult time differentiating between "sight
*may*
provide a bias that overrides true differences" with "sight *always*
overrides true differences and makes your comparison invalid". They
should
know better, but they don't seem to be able to allow even the possibility
that there are real differences and that you might have heard them."

We don't prove a hypothesis, we fail to unprove it,ie. after time and
enough effort has been put into a hypothesis and it continues to be
unsupported, we turn to more fruitfull lines of questions. The above
hypothesis is one such. After decades of tests in humans the idea of
there being no expectation bias has failed to be supported. The
continuing hope that one more test will suddenly confirm there is no such
bias is very slim and we can't really put any faith into it. But if one
insists, it would be an easy test to do it once again with amps in a
structured blind test in the hopes that finally results will tend away
from random.


If (in separate, isolated trials) seven test subjects are are left
alone in a room with 7 different amps and a Stax Lambda and SRD-7
connected to a high-quality source (I owned the Stax cartidge at the
time, on a Magnepan arm and Thorens turntable), with familiarity of
how to connect these to the amps, and after these subjects are given
however long they want to listen to the set-ups, and all the test
subjects report that the Bryston sounds dull and the PS Audio sounds
bright, and the Harmon Kardon sounds kind of flat and lifeless, and
the Hafler sounds kind of flabby, and the Denon sounds good in most
respects but not outstanding in any, would that be good enough for
you?

Then do it. They will.

Michael Scarpitti wrote:
chung wrote in message news:AVR0c.160762$uV3.709405@attbi_s51...
wrote:
"not knowing what's being played. In fact, I would expect Keller to have
had a better hearing acuity than most of us."

Ms. Keller was deaf blind.

Oops, didn't know that. So why would Mr. Scarpitti say that even she
could tell the difference? Hmmm...

Blind folk have the same hearing as everyone
else, they only use it differently and pay more attention to sounds in a
way sighted folk don't. In the case of testing audio gear, blind folk do
no better then do sighted folk. Blind folk do pay more close attention to
spacial clues based on sound reflection, which might mean they more easily
detect it in recorded music or know it is false if reverb etc. are used to
produce spatial information. They might be able to better comprehend the
space a recording was made in, or know if it is a multi layered pan pot
product.

Yes, this was a way of saying that even a blind and deaf person could
detect these diferences....


So, great, then you should have no problem passing a DBT then, correct?
Further more, you are also implying that these differences will show up
in measurements, too.

chung wrote in message ...
Michael Scarpitti wrote:
"W. Oland" wrote in message ...


The ability of knowledge and/or belief to influence how a person perceives
something is well established. For example, that is the reason that
placebos are used in the trials of new pharmaceuticals. Depending on what
is being tested, up to 40% of the people taking the placebo report
improvement in their medical condition (and also side effects.) This is
completely based on the =expectation= that the drug will make them better.
As such, the "real" drug under test must do significantly statistically
better than the fake one.

It cannot make a Harmon-Kardon amp sound consistently(!) different
from a Hafler amp, especially when I have no idea how each is supposed
to sound. It cannot make five different amps sound different from each
other, and consistently so.


The same thing applies to auditioning audio equipment, whether amps,
speakers, cables or whatever. If you know which piece of equipment you are
listening to at any given moment, your knowledge and beliefs about that
item are going to influence your perception no matter how many times you
tell yourself otherwise.

I have said this before, and I am going to say it again, for the LAST
time:

I had NO beliefs about how these amps were supposed to sound. It was a
'blind' trial, in the sense that I had not listened to any of the amps
before bringing them home for listening tests.

Hafler
PS Audio
Harmon-Kardon
Bryston
Sony

They all sounded different.

How can my 'beliefs' affect my judgement, when I had no 'beliefs' to
start with?!

I listened with Stax electrostatic earspeakers connected directly to
the power amps. Perhaps your system is not as critical.

But DON'T tell me I cannot hear differences between amps this way.
Hellen Keller could hear them!


Several questions:

1. Did you level-match during your listening tests?

I listened in succession to the same piece of music. I adjusted the
volume as necessary. The differences I heard had nothing to do with
volume. They were GROSS differences.

2. Do you think you can tell them apart in a DBT?

I KNOW I could, with perhaps one exception. Two were fairly close, but
the others were all quite different. The Harmon Kardon was similar in
tonal quality to the Denon, but it had less dynamic impact, which was
not noticeable until sharp, powerful bass transients occurred. Then it
was obvious. If you played Mozart's soft strings on the two, it would
be hard to tell them apart. But play Mahler's 5th, and it's a dramatic
difference.....

3. Can you tell differences between cables?

Yes, I can.

BTW, whether Hellen Keller could hear them is irrelevant. Blind means
not knowing what's being played. In fact, I would expect Keller to have
had a better hearing acuity than most of us.

Uh.....she was blind and deaf...

"Michael Scarpitti" wrote in message
...
Bruce Abrams wrote in message
...


If you allow for the fact that sight *may* provide a bias that overrides
true differences than you must control for it, always. Failure to do so
leaves open the possibility that you may have been influenced by sighted
bias. There would simply be no way to know whether the listening
results
were valid or bias influenced, and no amount of arm waving shouting
"DON'T
TELL ME WHAT I HEARD" will change that fact. Bias controls are
necessary
not because the biases always exist, but exactly because they may exist.

I would like you to explain how 'sighted bias' explains what I heard
in detail, not just in general. To claim 'you heard differences
because you expected to' is not an explanation at all. It does not
account for, for instance, the nature of the differences I heard
(dynamic compression, brightness, dullness, etc.). It is the same as
explaining fire by invoking 'phlogiston'. It 'explains' nothing.

Michael, before anyone can answer the question of why you heard what you
thought you heard, the question must first be answered, "Did you really hear
it." This is the same question that consumer researchers must answer all
the time and the reason that blind testing is the only testing methodology
that is ever considered. What you're asking is the equivalent of being
presented with a can each of Coke and Pepsi with labels in full sight,
telling us you prefer the Coke and then asking us to tell you why you liked
the Coke better. Until you can prove under blind conditions that you can
distinguish between the two, there is no reliance on your initially stated
preference.

"Piotr Wyrostek" wrote in message
news:7241c.443481$I06.4948340@attbi_s01...
*snip* quoted text

Yes, and the same problem exists when you listen to A or B in a DBT. That
is,
you assign a "label" to the A sound and then to B sound in the same way
(i.e that A is "rolled off and that B is "bright") as you described above.
There is no difference if you know that the amp is "Harman" or "A".

So when you listen to X, you try to hear if it is "bright" or "rolled of".
Since this "sound labels" where constructed in your mind, you have to
obtain
random results from this test, because neither A nor B nor X is
bright/dull.

If A & B do, in fact, sound different, I should be able to correctly assign
"sound labels" with the repective amps and to then identify X as being
either A or B. What is your point?

The problem is that the results are random and they are random
INDEPENDENTLY
FROM ANY REAL DIFFERENCES between A and B, if any exists.

The results are only random if there aren't any audible differences between
the amps? What are you trying to say?

This invalidates the whole idea od the blind testing.
That is, the (correct) premise, that what we hear is influenced by not the
sound
alone, invalidates the DBT testing method.

The purpose of blind testing is to remove the variables other than sound.
If you don't know what amp is playing, it's impossible to prejudge it based
on anything other than its sound, and if its sound is audibly different than
another amp, you should be able to hear the differences and correctly
identify X.

wrote in message ...
"this kind, and ask to take them home. Hook them up to a set of Stax
Lambdas through a transformer such as the SRD-7."

Why is the above required? If one were to pursue this line, the possible
interaction of the transformer with the output of the amps would have to
be ruled out as the cause for any difference in a dbt.

But since I plant to use the amp with the headphones, any such
interaction bears on my purchasing decision.

I also listened with my speakers, with which the differences were
somewhat less audible.

"W. Oland" wrote in message ...
On Sun, 29 Feb 2004 20:18:11 +0000, chung wrote:

You seem to have totally missed the point here. No one is arguing that
Michael can hear those differences sighted. The argument is whether
those differences are still there, if he does not know what is being
played. Michael believes that there is no way that expectation bias can
lead to differences, despite the body of research that indicates that
indeed such biases exist and overwhelm subtle differences. Michael's
viewpoint is being challenged here, not his ability to hear or not hear
differences sighted.

The ability of knowledge and/or belief to influence how a person perceives
something is well established. For example, that is the reason that
placebos are used in the trials of new pharmaceuticals. Depending on what
is being tested, up to 40% of the people taking the placebo report
improvement in their medical condition (and also side effects.) This is
completely based on the =expectation= that the drug will make them better.
As such, the "real" drug under test must do significantly statistically
better than the fake one.

You must also understand the drugs are tested on people who are ill
and are not necessarily the best judges of the effects.

-----------------------------------------------------------------

Here is a typical study, on Zoloft:

-----------------------------------------------------------------
Table II
Treatment-Emergent Adverse Experience Incidence in
Placebo-Controlled Clinical Trials*
-----------------------------------------------------------------
Percent of Patients Reporting
Zoloft Placebo Difference
Adverse Experience (N=861) (N=853) Percentage
Autonomic Nervous System Disorders
Mouth Dry 16.3 9.3 7.0
Sweating Increased 8.4 2.9 5.5
Cardiovascular
Palpitations 3.5 1.6 1.9
Chest Pain 1.0 1.6 -0.6
Central and Peripheral Nervous System Disorders
Headache 20.3 19.0 1.3
Dizziness 11.7 6.7 5.0
Tremor 10.7 2.7 8.0
Paresthesia 2.0 1.8 0.2
Hypoesthesia 1.7 0.6 1.1
Twitching 1.4 0.1 1.3
Hypertonia 1.3 0.4 0.9
Disorders of Skin and Appendages
Rash 2.1 1.5 0.6
Gastrointestinal Disorders
Nausea 26.1 11.8 14.3
Diarrhea/Loose Stools 17.7 9.3 8.4
Constipation 8.4 6.3 2.1
Dyspepsia 6.0 2.8 3.2
Vomiting 3.8 1.8 2.0
Flatulence 3.3 2.5 0.8
Anorexia 2.8 1.6 1.2
Abdominal Pain 2.4 2.2 0.2
Appetite Increased 1.3 0.9 0.4
General
Fatigue 10.6 8.1 2.5
Hot Flushes 2.2 0.5 1.7
Fever 1.6 0.6 1.0
Back Pain 1.5 0.9 0.6
Metabolic and Nutritional Disorders
Thirst 1.4 0.9 0.5
Musculo-Skeletal System Disorders
Myalgia 1.7 1.5 0.2
Psychiatric Disorders
Insomnia 16.4 8.8 7.6
Sexual Dysfunction-
Male (1) 15.5 2.2 13.3
Somnolence 13.4 5.9 7.5
Agitation 5.6 4.0 1.6
Nervousness 3.4 1.9 1.5
Anxiety 2.6 1.3 1.3
Yawning 1.9 0.2 1.7
Sexual Dysfunction-
Female (2) 1.7 0.2 1.5
Concentration Impaired 1.3 0.5 0.8
Reproduction
Menstrual Disorder (2) 1.0 0.5 0.5
Respiratory System Disorders
Rhinitis 2.0 1.5 0.5
Pharyngitis 1.2 0.9 0.3
Special Senses
Vision Abnormal 4.2 2.1 2.1
Tinnitus 1.4 1.1 0.3
Taste Perversion 1.2 0.7 0.5
Urinary System Disorders
Micturition Frequency 2.0 1.2 0.8
Micturition Disorder 1.4 0.5 0.9
-----------------------------------------------------------------
*Events reported by at least 1% of patients treated with
Zoloft are included.
(1)% based on male patients only: 271 Zoloft and 271 placebo
patients. Male sexual dysfunction can be broken down into
the categories of decreased libido, impotence and ejaculatory
delay. In this data set, the percentages of males in the
Zoloft group with these complaints are 4.8%, 4.8% and 8.9%,
respectively. It should be noted that since some Zoloft
patients reported more than one category of male sexual
dysfunction, the incidence of each category of male sexual
dysfunction combined is larger than the incidence for the
general category of male sexual dysfunction, in which each
patient is counted only once.
(2)% based on female patient only: 590 Zoloft and 582 placebo
patients.
-----------------------------------------------------------------

Other events observed during the premarketing evaluation of
sertraline:
During its premarketing assessment, multiple doses of sertraline were
administered to 2710 subjects. The conditions and duration of exposure
to sertraline varied greatly, and included (in overlapping categories)
clinical pharmacology studies, open and double-blind studies,
uncontrolled and controlled studies, inpatient and outpatient studies,
fixed-dose and titration studies, and studies for indications other
than depression. Untoward events associated with this exposure were
recorded by clinical investigators using terminology of their own
choosing. Consequently, it is not possible to provide a meaningful
estimate of the proportion of individuals experiencing adverse events
without first grouping similar types of untoward events into a smaller
number of standardized event categories.

-----------------------------------------------------------------

The same thing applies to auditioning audio equipment, whether amps,
speakers, cables or whatever.

Unwarranted claim. No basis from generalization from drugs to audio.
They are completely different sorts of experiences.

If you know which piece of equipment you are
listening to at any given moment, your knowledge and beliefs about that
item are going to influence your perception no matter how many times you
tell yourself otherwise.

What knowledge? What belief? What did I know about Harmon Kradon, PS
Audio, or Denon BEFORE I tried them? Nothing! I did not listen to
these products before I tried them out.

That said, there is absolutely nothing wrong with allowing your beliefs to
enhance your enjoyment of music when using a particular item. Just don't
confuse that enjoyment with the results of a double-blind test under
carefully controlled conditions. They are two different animals.

I have no 'beliefs'.

"explain how 'sighted bias' explains what I heard
in general. To claim 'you heard differences
to' is not an explanation at all. It does not
tance, the nature of the differences I heard
, brightness, dullness, etc.). It is the same as
nvoking 'phlogiston'. It 'explains' nothing."

Science is about defining principles which by observation and expeariment
account for as much information as possible. What you are asking in
principle is why the observed and confirmed byy experiment principle
should not
apply to your experience. In principle the questioned cann't be answered
for an individual example. What can be done is to say that all things
being equal, there is no reason to think this is an exception to the well
observed and confirmed process of looking into such things over many
years. To answer the question in a specific instance is approached as any
other single example, apply the same test to it. If those percieved
differences, or more accurately in this example, the ability to apply
previously percieved observations to each amp when in a dbt will be any
more then would random applications of same. In which case one can
reasonably conclude that percieved differences assigned to each amp
originate in some mental perception process independent from some basic
nature of each amp.

Michael Scarpitti wrote:

chung wrote in message news:AaL0c.95414$4o.117307@attbi_s52...

Michael, I and others have described similar tests here under similar
conditions, and have always been told we are just imagining the differences
based on "expectation bias". Expectant of what they can't say.

Unfortunately, some of the members of this forum, while intellectually
understanding it, have a difficult time differentiating between "sight *may*
provide a bias that overrides true differences" with "sight *always*
overrides true differences and makes your comparison invalid".

This is a misrepresentation of those members' position. What some of us
are saying is that you have to be cognizant of the effects of
expectation bias, and take proper steps to control it , if you really
want to find out if there are *audible only* differences. We always have
said that if the differences are big enough, like those between
speakers, then you don't really need DBT's to differentiate them. We
don't say that "sight always overrides true differences" (in fact we
argue if the audible difference exists in the first place), we are
saying that expectation bias is very likely to override subtle
differences, and that DBT is the best way to control for expectation
bias. In the case of competent amps and speakers, we know that those
differences should be subtle at best, from measurements like frequency
response, distortion and signal-to-noise ratio tests.

What am I 'expecting'? How can I 'expect' the Bryston to sound dull
and the PS Audio to sound bright, when I never heard them before? How
can I 'expect' them into sounding the same in repeated trials?

I asked you whether you did level matching, and you have not responded.
That is one major requirement on a listening test.

As many people have explained to you, expectation bias comes in if you
know that you are listening to different products. It is, to a large
degree, subconcious. Your mind expects to find differences if you know
that the products are different.


They should
know better, but they don't seem to be able to allow even the possibility
that there are real differences and that you might have heard them.

No, they do, that's why they recommend the Harry Lavo's and Michael
Scarpitti's of this newsgroup to do controlled tests to see if those
differences are real. Heck, they even throw in real money to motivate
them, in the case of cables.

The control of the test is valid. I connect A to Stax and listen. Then
I connect B to Stax and listen. Then I connect A again and listen.
Then I connect B again and listen. Then I connect C and listen,
etc....


One more time, have you level-matched?

What you are doing is fine if you want to select an amp. If you really
want to know if there are audible differences, you need to provide
control, as we have explained many times, unless the differences are
gross. There is nothing in these amps' specs or measurements that would
suggest the kind of gross difference that you heard (even Keller could
hear that!). The existing body of knowledge in the field of
psychoacoustics tells us that when detecting subtle differencs,
expectation bias has to be controlled for, so what you are doing is not
adequate if you want to detect those differences. Do you have any
objection to the DBT methodology, which removes expectation bias?

Given that that is how we use amps, that is valid for testing
them...we hook them up and listen...

Not good enough for detecting subtle differences. It is up to the
individual to do whatever he wishes to select equipment, of course.


I took all these amps home because I did not know anything about them.
I had not been hanging around audio salons all that much to have
formed any opinions on any of them. The only one of which I had formed
any impression was the Harmon Kardon Citation, as I had read some of
their literature.


Explained over and over again already.

On Tue, 02 Mar 2004 04:30:57 +0000, Nousaine wrote:

Bruce Abrams wrote:

"Michael Scarpitti" wrote in message

...snip to content .........

By the way, I asked a friend to listen along with me. His opinions
were exactly the same.

And he knew what he was listening to as well, correct?

Here's another take on the "we all heard it" consensus. In the group
open listening sessions I've witnessed the routine is interesting:

First the Owner/Host/Presenter (they are nearly universally comparative)
does a direct comparison or often a "comparison" with other products
that aren't present, and asks "What did you think?" or, more common
"Which Did You Prefer?" In direct comparisons there are often apparent
level differences; but never is there a controlled attempt to level
match. Further the O/H/P often primes the well with comments prior such
as "we'll most people hear x,y and z).

Next one ot two listeners express a comment and IF it's not the answer
the O/H/P wants he says "Let's Try It Again with BETTER Program
Material" and then repeats the process. If the "group" hasn't delivered
the expected results this gets repeated UNTIL the 'right" or at least
acceptable answers are obtained and then the presentation is finished.

Listeners seldom say "they sounded the same to me" and there are often
negotiations about what the real sound was "Well maybe you didn't hear
the do-dah midrange but surely you heard the increased transparency...?"

And eventually those who 'are' willing to speak will come to 'agreement'
on what they heard; and then the experiment will go into anecdotal
history that "everybody heard this."

A number of books out there in the Scientific realm comment on how
many projects are started based on "anecdotal" activity. It is this
realm where an awareness level is brought to the attention of others
working in a given Scientific domain and interest is raised. So be a
bit wary of downplaying "anecdotal" notations. Unless "anecdotal"
infomation flow is allowed many important facts will be squashed.
Getting to the truth of a given issue is often assisted greatly by the
much derided "anecdotal" information.

Let me give you an interesting anecdote about this process. Clarke
Johnson, an avid high-end audio retailer, and long time promoter of
"absolute polarity" gave a paper at an AES Convention where he said that
he'd done Triple Blind Experiments (3X-Blind, according to his
interpretation meant that subjects didn't "know" that they were in an
experiment) where 22 of 22 subjects reliably "heard" absolute polarity.

At a subsequent CES show I was in a exhibit room and I saw Clarke
expressing his beliefs about AP to a Conventioneer. I said that nothing
he was saying had ever been verified under bias controlled conditions.

Bias Controlled...you are going to control this? Every opinion you
have has "bias" all wrapped up in. Enjoy your bias...you sure can' t
escape it!! BTW..bias is not bad..contrary to modern day "political
correctness"...it is based on your experiences regarding matters that
required a mental "yea" or "nay"...it is part of your intellect.
...and can help you make a better decision.

So he then announced to the room; "hold on everybody we're going to do a
test" and he then played a 2-minute segment of an LP; walked behind the
tower speakers and made a 'do' about doing something back there.

Then he repeated the same music segment; and then asked "Did anybody
hear a difference?" The guy next to me looked quizzical, shrugging his
shoulders and then finally raised his hand when he saw a few others
doing so.

Then Clarke counted the raised hands and loudly proclaimed "See 6 out of
6 heard a difference." I then pointed out that I hadn't raised my hand
(they did not sound different to me) and he conceded "OK 6 out of 7"
totally ignoring that there were at least a DOZEN listeners present.

Open social listening sessions often have the same interpretative error
mechanisms; no data is compiled; negotiation between subjects is
allowed, subjects who do not speak out vocally are ignored and only
acceptable answers are accepted or acknowledged.

Mercy..".interpretative error" compared to what..who defines the
standard that qualifies an "interpretive error"..This stuff is
getting a bit thick. There are variables in the "ear-brain"
interpretation between each individual. Those out there that have a
standard all figured out are to be commended... or perhaps the brunt
of a few "guffaws". Perhaps, isolating parts of the mental process
during the listening process will evolve into a new
discipline...NOT!! Mercy! This is a bit much...reality where art
thou?? This is heading into thicket of "illogic"...someone save us
all from these mental distortions!

As a group, some of them, browbeaten by those in the crowd that has
it all figured out, others that merely comment on the positive or
negative character of the component being listened to..so be it.
Also, get rid of the "test" syndrome! This implication that somehow
this "no data compiled" and "subjects make comments" are a dreadful
sin. This is somewhat humorous. There will be an interchange of
comments and ideas. With all the variables out there
this is what the session will evolve into. This is good, one cannot
compile any data that will not be somewhat different in another
session. Surely, one recognizes this characteristic in this Audio
domain! Unless they have a super scientific switching device that
can shave the audio spectrum down to make everything sound the same.
For those that need that...have at it!

Perhaps the most humorous comment is that:
"...negotiation between subjects is allowed...".

Jeez, what was the purpose of the session? To arrive at a conclusion
that won't vary in the next session? The "real world" is not a factor
in this scenario. Do I detect an agenda, one that almost always
clouds up reality? Then it is announced as a "test" that can be
quoted in a browbeating manner?
Happens on this forum all the time!

Forget any ideas about "numericalizing" a social listening session or
getting the same results over two sessions. Forget about setting
unrealistic rules to tilt the results toward your view of the audio
Universe.

I repeat...one cannot allow for all the variables in each individuals
"ear-brain" construct. You're chasing
"hot air" to think that somehow one can force a
listening session to adhere to some agenda that takes on an evangelist
like quality. Then, go about quoting the results as a "test" that
renders strength to your agenda. This will not work out here in the
"real world"...one with this problem will have to gain sympathy from
others of like persuasion...it is not in these newsgroups.

Don't think this happens? Think about it. Try it yourself.
(It is a given that the scenario painted above will give
some kind of expected results...if not, badgering will occur until
something preferred comes around..so what's new??)

Yes, this happens...but one cannot fix all the sins you read into the
lax rules...and, neither you or I have the answer with all the
uncontrolled variables of the ear-brain constructs interpretations. Do
try to enjoy the music...this evangelism in the Audio Domain
seems a bit "out of place"...don't you think?

To summarize...to attempt to isolate functions of your
mental process to resolve an imagined problem in sitting in your own
quiet listening space seems to drift into the realm of illogic. It
also drifts into the problem area of "semantics"...ad infinitum. For
instance ask 5 people what the meaning of "bias" is...note all the
variables attributed to it. Who, in their right mind, wants to tread
into this bottomless pit??

Leonard...

P.S. A technique that seems to produce some results is as follows:

A friend took a group of cables to a neighbors home and suggested
that opinions be given about each cable...no cable names were given.
Just a simple.." what do you think about this one." Then some
suggested certain comparisons be made. No one knew what "brand
names" were in the group of cables...just #1 thru #5. Out of this
there was a general opinon that #2 was somewhat different in a
rather pleasant manner. Some of the cables came from the mid-90's.

The same session was held a few months later...the
results were different. Case closed. Everyone left content with
the fact that there are variables out there we do not have a
handle on yet. We all left quite content that we didn't know the
answer...but, we enjoyed it all..and went home and turned on our
systems and made mental comparisons. We all knew there would be
nothing definitive reached from the session...but we did hear an
interesting cable or two and had some good audio chatter. No
regimen
here...no agenda..just curiosity to listen to varying cable
characteristics. A good time was had by all. Some new CD's were
played...the music was good... ..that is what this Audio domain is
all about.

Above all..there was an endearing respect for each individual's
opinion..and some decent wine at the end of the session. Note also,
there was no one there telling anyone what they did or didn't hear.
A pleasant situation. Oh yes, at that time we were listening on a
fairly new Panasonic S55 (Number?) that cost around $129. This
merely confirms that these devices are reaching the "commodity"
level. All the more interesting is that it played about every format
on this Earth and seemed quite good at it. (See the a thread now
running here, I think...about
this Panasonic model)

(Michael
Scarpitti) wrote:
If anyone says 'the fact that you knew which product you were
listening to invalidates any audible evaluation you may have made' is
ludicrous.


Stewart Pinkerton wrote:
No, it's a simple fact, easily supported by experiment in the case of
subtle differences, such as among nominally competent amplifiers. Why
are you so adamant in refusing to accept simple truths?


Truth? It's your opinion stated as fact... I have never heard two amplifiers
that sound the same - the greatest differences were between tubed and solid
state amps - competent ones - and you deny those differences exist.

Nope, your comparison method is faulty. The odds are that some of them
did indeed sound different, but others did not.

I can demonstrate a tube amp and a SS amp which sound obviously and
vastly different to a room full of audiioophiles - and I won't
actually have to change the connections for them to 'hear' the
difference.............


So what?

Why will you not accept the plain fact that sighted comparisons are
fatally flawed, and at least *try* it for yourself. What are you
afraid of? Will your ego not admit even the possibility of error?


Why not admit the fact that your application of the DBT *most likely* is
fatally flawed. Will your ego not admit even the possibility of error?

Of course it was consistent, when you *knew* which one was connected!
It's called reinforcement, and any first-year psy student can explain
it to you. This isn't new knowledge, nor is it even in dispute in
medical circles, which is why double-blind testing is *always* used in
medical research.


Yes it used in medical and other research. But until a someone provides a
*validation test* for open-ended audio component comparisons with music as the
program - your strong beliefs are just speculation.

The point is, it is simply not worth my time to converse with those
who deny that such differences can be heard at all.


Not denying anything of the sort, merely pointing out that your
comparison method is fatally flawed. Try it again under blind
conditions, and you'll find that many of those 'night and day'
diferences magically disappear. Those that remain are *real*
differences, and you will have achieved something. At the moment, you
are sticking your fingers firmly in your ears................


Can you spell *v-a-l-i-d-a-t-i-o-n t-e-s-t*?
Regards,
Mike

Michael Scarpitti wrote:
Steven Sullivan wrote in message ...

Well, yes, of course it was. But alas that doesn't mean that 'sound' was
real. A false positive effect of that nature is by no means
improbable.

Impossible, to be honest.

So you have no aural imagination or have absolutely perfect control over
it?

That's like a machine, not a human being.

"Nousaine" wrote in message
...
"Harry Lavo" wrote"

...snips to content ....


I think the subjectivists actually find this topic of great interest,
based on how frequently they post in these threads...


You think the objectivists ever let an assertion of heard differences
pass
without comment or challenge?

Try this:

I, Tom Nousaine, analyzed nearly 2 dozen published controlled listening
tests
of power amplifiers that had been conducted to that time, of which only 2
(both
high-output impedance tubed amplifiers; one of which was authored by Arny
Krueger) had confirmed positives for audibility.

Prior and subsequent to that time I've personally confirmed that more than
a
dozen amplifiers I've owned (or used) all sound exactly the same when
operated
within their power limits (Heathkit (2), Parasound (3), Stewart (2) ,
Fidek,
Samson, Adcom, Bryston (4), B&K, SUMO, PASS and Yamaha) either to me or
the
several dozens of subjects employed under listening bias controlled
conditions;
even when conditions were maximally implemented to high-light possible
differences.

But whenever I mention any given experiment subjectivists never let that
pass
without challenge.

The above suggests two possible conclusions:

1) there are no sound differences between amplifiers, except possibly
between tube and solid state based on the output impedance of the tube amp,
or:

2) the test used interferes with and confuses the normal ear-brain
interpretation of music that audiophiles normally use, and therefore is
insensitive to any but the grossest and simplest differences (eg. large
two-dimensional differences in volume or frequency response).

You and other converted believers simply ignore the latter possibility and
have never attempted to validate the adequacy of your preferred tests.

I and other subjectivists over the years have argued the case for the
possibility that number two is the operative factor, and have argued for
alternative tests, only to have it fall on deaf ears.

Subsequently, most subjectivists have simple given up and gone on making
choices their own way and living happily ever after. I and Mike and Wheel
and a few others have chosen to stay, and stay vocal...but without letting
it ruin our enjoyment of the hobby.

Michael Scarpitti wrote:
Bruce Abrams wrote in message ...
"Michael Scarpitti" wrote in message
news:YDR0c.160642$uV3.708646@attbi_s51...
*snip*
(snip)


After going through these amps several times, I began to note which
ones had a particular sound, and that sound was consistent from one
trial to the next.

And each time you listened to 'A' which you thought you found bright, you
reinforced that it did, in fact, sound bright.

Not so. I listened again, and confirmed that 'A' sounded bright AFTER
listening. I cannot make this any plainer.

Repeated trials confirmed initial impressions.


The point is, it is simply not worth my time to converse with those
who deny that such differences can be heard at all.

If you would like, go to an audio shop that carries used products of
this kind, and ask to take them home. Hook them up to a set of Stax
Lambdas through a transformer such as the SRD-7.

Then you will hear the differences.

I've already heard exactly such differences between cables, right up until I
realized I was hearing the attributes I'd ascribed to cable 'A', only I was
really listening to cable 'B'. Until you allow for the existence of sighted
bias, a phenomenon that is universally acknowledged to exist, you are
correct in that further conversation on the subject is meaningless.

How can 'bias' lead me to believe that two amps that I have never
heard before. know nothing about, and have no opinion of, sound
consistently different, that is, have consistent sonic characteristics
from one trial to another and that mark them as different from each
other? That is impossible, I put it to you.

It's quite possible, ineed predictable from standard
psychological principles. Your first impression is based on an
expectation of difference; from then on you have the memory
of what you thought they sounded like the first time.

It's *possible* the amps sounded different. It's at least
as likely , and arguably *rather more* likely, that they didn't. Your
method by itself cannot resolve the question. That's due to
simple facts of human psychology.

I had formed no opinion of 'Hafler' sound or 'Harmon Kardon' sound or
'Denon' sound. I had no idea what to expect. The Harmon Kardon
Citation amp had the most impressive literature, and I expected this
one to be rather good-sounding. It was not. It was rather
disappointing, in fact among the very worst. The Denon was clearly
superior. I had no expectation that this would be the case.

You misunderstand what is meant by 'expectation bias'.
The 'expectation' in question is that apparently
different devices will *sound* different.

The point is that I was judging only how they sounded. I did not allow
the sales literature to sway me.

Even if that's true, it does *not* eliminate a fundamental source of bias:
the certain knowledge that the component you are listening to at point B is not
the same one that you listened to at point A. That;s *all* that's required
to generate expectation bias.

--

-S.

"They've got God on their side. All we've got is science and reason."
-- Dawn Hulsey, Talent Director

Michael Scarpitti wrote:

I would like you to explain how 'sighted bias' explains what I heard
in detail, not just in general.

If what you "heard" you only imagined, then we can't explain in detail what
you "heard," because we can't know everything that was going on in your head
at the time. What you *imagined* you heard could have been affected by the
order in which you listened to the amps, for all we know. All "sighted bias"
offers is a *possible* explanation for two things: 1) the fact that you
perceived a difference among these amps at all; and 2) the fact that, once
having identified a certain sound with each amp, your subsequent auditions
confirmed those impressions. That this explanation is indeed possible is a
proven scientific fact, and Steven Sullivan has suggested a few textbooks
which will confirm that.

A basic truth about listening comparisons is this: If you know what you are
listening to, then everything you've ever heard, read or thought about that
component can affect how you hear it. That's inescapable, my friend.

To claim 'you heard differences
because you expected to' is not an explanation at all. It does not
account for, for instance, the nature of the differences I heard
(dynamic compression, brightness, dullness, etc.). It is the same as
explaining fire by invoking 'phlogiston'. It 'explains' nothing.

If you really want to understand this, may I respectfully suggest that you
acquire some background in the science behind it. Sullivan has given you a
place to start.

bob

__________________________________________________ _______________
Get a FREE online computer virus scan from McAfee when you click here.
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Stewart Pinkerton wrote in message news:T%31c.23360$ko6.217138@attbi_s02...

Gosh, Stewart, how long did it take you to test every human and every piece
of wire ever used by them, and then verifying "competency" tests on those
that might have sounded different, to prove you point.

I don't have to, since all existing evidence and all medical and
engineering knowledge, says that I am right about this. If *you* wish
to claim otherwise, then that is an extraordinary claim, and the
burden of proof is on *you*.

No, no the burden of proof is on you! I have two witnesses to a
phenomenon that YOU say CANNOT exist. Prove us wrong!

On Mon, 01 Mar 2004 18:23:23 +0000, Stewart Pinkerton wrote:

On Sun, 29 Feb 2004 19:32:27 GMT, lcw999 wrote:

Now, having said that, I am aware that some participants
of this forum...long since committing themselves to a
basic "...all sound the same..there is no difference..."
mindset..will pile into this somewhat humorous fray.

They will be very adamant in knowing what "you" can
and can't hear! The humor of that stance comes to
play when one can easily follow the logic that you
or I, nor anyone knows what another individual's
mental processes are doing to the interpretive
processes. This is unique to each individual.

The humour is however somewhat dissipated when you consider that what
is being said is analagous to my stating as an absolute fact that
*you* cannot run a mile in three minutes.

In the realm of "Ethics-Philosophy" this is akin to tossing
out a known given...then attempting to spread all that
"known" quality over the issue in question...it treads very
close to what is termed a "silligism" in that realm of study.
My stance is an absolute...yours is shaky..this all takes
on a quality of immaturity.

The point of course is that no human can do this, in the same way that
there is *no* evidence that *any* human can tell apart two nominally
competent cables (i.e. not comparing 8AWG to 28AWG or other such
silliness). oops..a qualification slips out.

Whup!...here comes the flow of "absolutes"..things like "no human"
and the like...NO evidence. Gads...in who's book?..what mindset?..
..this redundant flow of absolutes. Sorry, these newsgroups are
full of this. A bit overworked...perhaps trite? Not convincing!

Perhaps, we have a group that missed their calling...
..neuro-research..or some study of the myriad of
variables in the mental processes on the analysis of
input from external sources.

Indeed so - and there has been a raft of research over the last
century into human hearing thresholds and acuity, all of which
supports the notion that 'wire is wire'.

Granted there might well be research on hearing "thresholds"
and "acuity"...but, this issue is not about thresholds and
acuity....those studies had to do with detecting a frequency
range upwards of 10 to 15k cycles...mainly in factories..I
have discussed that issue with those that administered those
test and one would not believe the variables in frequency
range that first detection occurs...there is a lot of difference
in the populace out there and their ability to hear even
up to 10K cycles. (Hertz in the current vernacular). Just
one of the variables I keep bringing up. Oh well...these
facts are wasted here!


So, I respect your hearing differences...no arrogance
here about what you do or do not hear. If one hears
cable or amplifier differences..so be it!

However, not one has been found who can do this when they don't *know*
what is connected, so your 'respect' is rather misplaced.

Gads...we've missed the point, as always....it is not "knowing what
is connected"..it is about one cable sounding a bit better or worse
than another. Simple issue, but hard to grasp?

Leonard...

Bruce Abrams wrote in message ...

I would like you to explain how 'sighted bias' explains what I heard
in detail, not just in general. To claim 'you heard differences
because you expected to' is not an explanation at all. It does not
account for, for instance, the nature of the differences I heard
(dynamic compression, brightness, dullness, etc.). It is the same as
explaining fire by invoking 'phlogiston'. It 'explains' nothing.

Michael, before anyone can answer the question of why you heard what you
thought you heard, the question must first be answered, "Did you really hear
it." This is the same question that consumer researchers must answer all
the time and the reason that blind testing is the only testing methodology
that is ever considered. What you're asking is the equivalent of being
presented with a can each of Coke and Pepsi with labels in full sight,
telling us you prefer the Coke and then asking us to tell you why you liked
the Coke better. Until you can prove under blind conditions that you can
distinguish between the two, there is no reliance on your initially stated
preference.

No way. The burden of proof is on you. I heard these differences as
plain as could be. It sometimes takes a while, listening to various
snippets of music, before all (or at least most) of the sonic
character is revealed. They may sound the same when listening to soft
female vocals, but then you put on something with big bass thwacks,
and it immediately becomes clear that one has more 'slam' and speed
than the other. That's why I would go back and listen again and again,
to try to get a general impression of each amp using a variety of
music types. The Harmon Kardom simply did not 'jump' when called for.
It simply limped along, smoothing out the dynamics and making them
soft and fluffy.

Blind testing of drugs consists typically NOT of comparing two drugs,
such as Zoloft and Paxil, but of a placebo and the genuine drug. The
analogy to audio listening evaluations is not close. Do you know that
the effectiveness of Zoloft and Paxil can be established, even though
the mechanism of action is not completely understood? If the patients
display and report improved mood, the drug works. Measurements of
blood concentrations are correlated with mood, and that's all they can
say. It is hypothesized that serotonin reuptake is blocked by these
agents (SSRI's) but that is only an hypothesis at this point.

Measurements of audio equipment are not comprehensive. They are cited
simply because they can be measured. It's like the old joke about
someone looking under a lamp-post for his lost key. You ask him:
'Where did you lose it?'. 'Over there', he replies, pointing to a dark
alley. 'Then why don't you look over there?', you inquire. 'Because
the light's better here'.

So, when you measure signals in audio, you're simply measuring what
you can measure easily: where the light is better. Whether all audible
differences have anything to do with what can be measured is unknown.

Till then, I'll trust my ears and not your pronouncements.

(Nousaine) wrote in message ...
"Harry Lavo" wrote"

...snips to content ....


I think the subjectivists actually find this topic of great interest,
based on how frequently they post in these threads...


You think the objectivists ever let an assertion of heard differences pass
without comment or challenge?

Try this:

I, Tom Nousaine, analyzed nearly 2 dozen published controlled listening tests
of power amplifiers that had been conducted to that time, of which only 2 (both
high-output impedance tubed amplifiers; one of which was authored by Arny
Krueger) had confirmed positives for audibility.

Prior and subsequent to that time I've personally confirmed that more than a
dozen amplifiers I've owned (or used) all sound exactly the same when operated
within their power limits (Heathkit (2), Parasound (3), Stewart (2) , Fidek,
Samson, Adcom, Bryston (4), B&K, SUMO, PASS and Yamaha) either to me or the
several dozens of subjects employed under listening bias controlled conditions;
even when conditions were maximally implemented to high-light possible
differences.

But whenever I mention any given experiment subjectivists never let that pass
without challenge.

Without good sources and speakers, such a testimonial is without
merit. The rest of the system must be of sufficiently high quality to
make the differences, if any, audible.

Harry Lavo wrote:
"chung" wrote in message
news:h1S0c.95108$Xp.423683@attbi_s54...
Harry Lavo wrote:

This is a misrepresentation of those members' position. What some of us
are saying is that you have to be cognizant of the effects of
expectation bias, and take proper steps to control it , if you really
want to find out if there are *audible only* differences. We always
have
said that if the differences are big enough, like those between
speakers, then you don't really need DBT's to differentiate them. We
don't say that "sight always overrides true differences" (in fact we
argue if the audible difference exists in the first place), we are
saying that expectation bias is very likely to override subtle
differences, and that DBT is the best way to control for expectation
bias. In the case of competent amps and speakers, we know that those
differences should be subtle at best, from measurements like frequency
response, distortion and signal-to-noise ratio tests.


What you are saying above is a very reasonable position. Unfortunately,
it
seems to believed only in the abstract here. When somebody such as
Michael
comes on saying he can hear differences in amps...there is no
questioning
him on his listening conditions

Actually I asked him whether he level-matched...


You did late in the game, but that was not the initial concern of those who
responded.

, no consideration of the age or circuitry of
the amps in question (despite one being a digital amp...the one chosen
at
that). .no discussion of his stated purpose or state of mind. All that
happens is that he is told because he listened sighted, he is surely
imagining things.

He did describe his listening conditions. Maybe you have missed that?


Yes, and listening over stax headphones should probably have raised a few
cautionary red flags among the objectivists, since listening on a really
good set of headphones lets your hear things that ordinary speakers and
room reflections might obscure.

Yes, listening via headphones is more sensitive. So is using pink noise.
But even a bigger red flag is the alleged "huge" differences that even
someone blind and deaf could discern. And his insistence that he was
immune from expectation bias.

Then the turmoil ensues.

The turmoil ensues because he refused to believe that expectation bias
could lead to false positives when trying to detect differences. Now
please answer this: do you agree with Michael on this key point? Do you
believe that expectation bias should be controlled for?


I believe it should be if you are after scientific proof.

Good. Let's remember that.

Done with a
blind, monadic, evaluative test.

We had this discussion before, and you could not make decisions once you
had to compare. Interesting that Michael told us he actively *compared*
the several amps. He did not have any difficulty discerning differences
in your so-called "comparative" mode. So why not do the standard DBT?

I think it is a ridiculous burden to put
on an audiophile trying to decide for himself what to buy...and it is an
equally ridiculous thing to demand that he do before he dare discuss on this
newsgroup the sound of products as he heard them on a "kitchen table test".

You seem to have missed the point. If he said he heard differences
between amps, that would be just an anecdote. What raised the discussion
level up was his insistence that expectation bias could never affect
one's ability to discern difference.

He is perfectly welcome to his belief, but when he flat out refutes the
existing body of knowledge on human perception, that's where challenges
come in.

Note that you have erected another strawman again when you said "it is a
ridiculous burden to put on an audiophile trying to decide for himself
what to buy". How many times do you need to put that up and burn it? Can
you tried to be more objective in representing viewpoints of those you
don't agree with?



They should
know better, but they don't seem to be able to allow even the
possibility
that there are real differences and that you might have heard them.

No, they do, that's why they recommend the Harry Lavo's and Michael
Scarpitti's of this newsgroup to do controlled tests to see if those
differences are real. Heck, they even throw in real money to motivate
them, in the case of cables.


Insisting on a test that the "testees" don' t believe is valid. Nice
'gotcha.

Now Harry, how does the word "recommend" become "insist"?


The insistance is that the test be a blind comparative a-b or a-b-x test
rather than a serial, modadic, evaluative test that happens to be blind.

But we never insist that he has to do that in selecting components. If
he wants to prove without doubt to us, of course then he has to use a
bias-controlled methodology, and DBT is such a commonly used
methodology. BTW, he did not think that he would have problem passing
the DBT, unlike in your case where "comparative" causes panic.


As far as I am concerned, you don't have to do any controlled testing.
You can pick amps/cables based on whatever criteria. However, when you
want to convince others that there is real, audible, difference between
them, you should use controlled testing like DBT to make sure that
expectation bias (and other stuff like mismatched levels) does not
invalidate your listening tests. DBT is the standard methodology on
difference detection for such a long time, that I don't see any reason
why Michael would have problem with it.


He may not have a problem with it. Other than to consider it a waste of
time. But he certainly didn't expect to be told that he was wrong, wrong,
wrong to have thought he heard different sound characteristics from the amps
because he didn't do the test double blind.

What he was told "wrong, wrong Wrong" was his insistence that
expectation bias could not lead to false positives. You believe he's right?

He might or might not have
heard such characteristics...he was given no benefit of the doubt.

I gave him the benefit of the doubt that he truly believes what he heard
was real.



So
don't get upset...it's a world view of theirs that you are not going
to
change.

All you need to change their world view is to pass the cable DBT test!
. Simple, isn't it?


Sure, would greatly simplify the objectivist world-view here if we would
just go away and stop challenging the test.

The funny thing is no one asked you to go away and stop challenging the
test. (In fact we even put up money hoping you would take the test.) And
you were the one who said that Michael should go away and find some
other topics to discuss...

Nobody asked him to go away. We just suggested he not tear himself apart
looking to convince you guys. It looks like he reached the same conclusion
on his own.

It did not appear that he is tearing himself apart at all!


You yourself put the smiley in your statement, meaning you know it is a
ridiculous statement that won't be accepted.

No, your interpretation is wrong. I put the smiley because I know that
you or others know that you will fail the cable test, and will not
participate. It is not because the test is ridiculous (why is it
ridiculous, Harry, given night and day differences?), it is because the
subjectivists are really afraid to learn that without sight information,
they do not have that touted ability to discriminate.

Why, because you are asking us
to "beat" a test that we think is flawed.

You said it's flawed because of that mystical comparative vs evaluative
dilemma. Others said that it is flawed because the test period is too
long, too short, snippets too long, too short, while in academics and
industry DBT's are used day in and day out.

Meanwhile, my efforts to point
out why I and others believe it is flawed and to propose a proper control
test have met with very little but stoney silence...as if the issue were
never raised.

Stoney silence? You seem to have very selective memory. If you are
looking for posts supporting your proposal only, yeah, I guess that was
stoney silence .

If something uncomfortable comes up, just ignore it, right?

Please reread the responses to your proposal.

The way to prove the test right or wrong is to devise the control test and
get on with executing it.

You seem to want to prove an established methodology is wrong. Yeah, go
ahead and prove it.

I say the best way to get to the other side of the fence is to open the
gate. You say the best way is to lower my head and keep charging the fence.
Which do you think has the best chance of getting us to the other side?

Nil, because you made up your mind a long time ago not to go there!

BTW, how would you know that Michael would fail a DBT on amps?


I don't know nor did I claim to know that he would. But like Mike Kueller,
I believe the test technique itself loads the test in favor of "no
difference". And I would never encourage him to undertake a loaded test.

Maybe because in most cases, there is really no difference?




But you can ignore them and instead focus on other topics of interest
here
on the forum.


I think the subjectivists actually find this topic of great interest,
based on how frequently they post in these threads...


You think the objectivists ever let an assertion of heard differences
pass
without comment or challenge?


You realize how many of these threads were started by subjectivists?


This one was started not once, but twice, by an objectivist.

And subjectivists would never let an assertion by the other side pass
without comment or challenge, so there you go...

"If (in separate, isolated trials) seven test subjects are are left
alone in a room with 7 different amps and a Stax Lambda and SRD-7
connected to a high-quality source (I owned the Stax cartidge at the
time, on a Magnepan arm and Thorens turntable), with familiarity of
how to connect these to the amps, and after these subjects are given
however long they want to listen to the set-ups, and all the test
subjects report that the Bryston sounds dull and the PS Audio sounds
bright, and the Harmon Kardon sounds kind of flat and lifeless, and
the Hafler sounds kind of flabby, and the Denon sounds good in most
respects but not outstanding in any, would that be good enough for
you?"

It is up to you to do the test, extraordinary claims require extraordinary
support. If the above were in fact to happen just as you say, it would
not at a stroke nullify the principle of expection bias. Before
questioning it one would want to investigate why this example was the
exception to the rule. For example did the output of the different amps
interact with the transformer way shuch as to change frequency responce
etc. in the headphones. We would also want to redo the test several times
with other panels so as to eliminate the possibility of a random occurence
of a pattern. It is possible to get 10 heads in a row in a coin toss.
Only after those and other considerations were ruled out would the now
established role of expectation bias be given another look. But to date,
we have one testimony of personal perception and a suggestion to have
others do likewise in the hopes of finding the bias is not supported, we
have nothing else. It would be far easier to choose the two amps judged
most different and see if in a dbt a pattern other then random would
occur, all the rest of your proposed test with all the attached
descriptive terms would not even have to be considered further.

"2) the test used interferes with and confuses the normal ear-brain
interpretation of music that audiophiles normally use, and therefore is
insensitive to any but the grossest and simplest differences (eg. large
two-dimensional differences in volume or frequency response).
"

snip

"I and other subjectivists over the years have argued the case for the
possibility that number two is the operative factor, and have argued for
alternative tests, only to have it fall on deaf ears."

This claim requires you provide the testing for it's support. How does
obscuring which device is active by covering connections with a cloth do
the above? That you have failed to do the testing does not provide any
support that it is valid,ie. to suggest alternative tests is not to undo
the current well supported principle. Considering the above, how do you
explain those cases where no actual switching was done but the other then
"gross" effects were reported to be heard as easily as before? In fact,
it is not more audio testing your theory above requires, it is a test
about the current test so as to attempt to show it not valid. Because dbt
is the standard in almost all research, that test would have to show why
human hearing was an exception. You are tossing rocks at the proceedure
of science, not the well established principle used in listening research
and it's application to establishing the thresholds of reproduction which
are audible..

"normanstrong" wrote in message ...
"Michael Scarpitti" wrote in message
news:YDR0c.160642$uV3.708646@attbi_s51...

The point is, it is simply not worth my time to converse with those
who deny that such differences can be heard at all.

If you would like, go to an audio shop that carries used products of
this kind, and ask to take them home. Hook them up to a set of Stax
Lambdas through a transformer such as the SRD-7.

Then you will hear the differences.

I don't deny that you heard differences. What I want to know is how
you hooked up the headphones to the amplifiers?

Norm Strong

Are you unfamiliar with Stax electrostatic headphones? They are called
'earspeakers'. You simply attach the cables coming from the Stax
transformer to the speaker outputs of your power amp. The headphones
are polarized by AC current, and the power amp supplies the signal.
They are extremely accurate and fast transducers. If you have a chance
to listen to them, do so.

Stewart Pinkerton wrote in news:aiq0c.3858
$ko6.13127@attbi_s02:

On Sat, 28 Feb 2004 23:42:20 GMT, (Michael
Scarpitti) wrote:

wrote in message news:e4P_b.6984$AL.139593
@attbi_s03...
Someone said they use extended listening in the dark to avoid light
stimulation and do hear differences. The key is not the level of
illumination but the knowledge of which is in the system.

Prove it! There is NO evidence to prove that the senses are influenced
by 'knowledge'.

This is arrant nonsense. There is a *vast* slew of such evidence,
starting with the classic 'false sighted' test where nothing is
actually changed, but enthusiastic audiophiles duly report 'night and
day' differences when they *think* that a tube amp or magical cable
has been introduced.

I too have observed sighted bias in a group of people as well as read
reports describing the effects. In addition, it is the rare individual
that does not succumb to peer pressure, arrogance, and other social
factors which would then influnce the conclusion or reporting of his
findings.

r


--
Nothing beats the bandwidth of a station wagon filled with DLT tapes.

chung wrote:
Michael Scarpitti wrote:

chung wrote in message news:AaL0c.95414$4o.117307@attbi_s52...

Michael, I and others have described similar tests here under similar
conditions, and have always been told we are just imagining the differences
based on "expectation bias". Expectant of what they can't say.

Unfortunately, some of the members of this forum, while intellectually
understanding it, have a difficult time differentiating between "sight *may*
provide a bias that overrides true differences" with "sight *always*
overrides true differences and makes your comparison invalid".

This is a misrepresentation of those members' position. What some of us
are saying is that you have to be cognizant of the effects of
expectation bias, and take proper steps to control it , if you really
want to find out if there are *audible only* differences. We always have
said that if the differences are big enough, like those between
speakers, then you don't really need DBT's to differentiate them. We
don't say that "sight always overrides true differences" (in fact we
argue if the audible difference exists in the first place), we are
saying that expectation bias is very likely to override subtle
differences, and that DBT is the best way to control for expectation
bias. In the case of competent amps and speakers, we know that those
differences should be subtle at best, from measurements like frequency
response, distortion and signal-to-noise ratio tests.

What am I 'expecting'? How can I 'expect' the Bryston to sound dull
and the PS Audio to sound bright, when I never heard them before? How
can I 'expect' them into sounding the same in repeated trials?

I asked you whether you did level matching, and you have not responded.
That is one major requirement on a listening test.

After he claimed there was *no such thing* as expectation bias --
a claim I suspect even his fellow subjectivists find beyond the pale
-- I posted some links to standard texts on sensory testing,
psychoacoustics, and psychology, that support the reality of
the phenomenon...and he hasn't responded to *that* either.

Explained over and over again already.

It seems clear that tutorial responses to Mr. Scarpitti cannot hope to
persuade him of anything, but can only be of service to the gentle,
and at this point quite possibly mythical, undecided reader.


--

-S.

"They've got God on their side. All we've got is science and reason."
-- Dawn Hulsey, Talent Director

Stewart Pinkerton wrote in message news:w241c.28038$PR3.503763@attbi_s03...
(snip)

If you would like, go to an audio shop that carries used products of
this kind, and ask to take them home. Hook them up to a set of Stax
Lambdas through a transformer such as the SRD-7.

Then you will hear the differences.

Not necessarily, plus I've already pointed out that this is a *bad*
method for comparing amps, since the load is not representative of
normal operation.

Since I actually DO use the amp to power the earspeakers, it is indeed
a perfectly valid test, in fact the most important test. If it sounds
bad with the Stax, I can't use it.

You must understand listening over speakers is somewhat less useful,
as the resolution is lower in speakers, and coloration of the room
enters into it. If you want to know what an amp REALLY sounds like,
connect it to a Stax transformer and earspeakers.

Michael Scarpitti wrote:

Bruce Abrams wrote in message ...

I would like you to explain how 'sighted bias' explains what I heard
in detail, not just in general. To claim 'you heard differences
because you expected to' is not an explanation at all. It does not
account for, for instance, the nature of the differences I heard
(dynamic compression, brightness, dullness, etc.). It is the same as
explaining fire by invoking 'phlogiston'. It 'explains' nothing.

Michael, before anyone can answer the question of why you heard what you
thought you heard, the question must first be answered, "Did you really hear
it." This is the same question that consumer researchers must answer all
the time and the reason that blind testing is the only testing methodology
that is ever considered. What you're asking is the equivalent of being
presented with a can each of Coke and Pepsi with labels in full sight,
telling us you prefer the Coke and then asking us to tell you why you liked
the Coke better. Until you can prove under blind conditions that you can
distinguish between the two, there is no reliance on your initially stated
preference.

No way. The burden of proof is on you. I heard these differences as
plain as could be.

Then why are you refusing to do a double blind test and hear the differences
again in this test? Should be a piece of cake. What are you afraid of?