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Harry Lavo
 
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Default Why DBTs in audio do not deliver

"Audio Guy" wrote in message
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In article ,
"Harry Lavo" writes:
"Audio Guy" wrote in message
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In article ,
(S888Wheel) writes:


snip irrelevant to what followsL


Wait a minute, wait a minute. Only sound? There is no music until the
brain has processed the sound and interpreted it as music.


You entirely miss my point, the mechanism of the delivery of music
via an audio system is audio, and nothing else. It's a point I'm
trying to get Elmir to acknowledge that I've asked and to agree or
disagree.

How about you, agree or disagree.


I don't know what "audio" is as you use it. I know what sound is. I know
what music is. I know what electricity is. I know what vibrations are.
And I know that components are designed to use those elements to deliver a
facsimile of music to our brains.

If this is what you mean by audio, then I agree.

If what your really mean is electrical output (of amps, wires, etc.) then I
disagree at least as conventionally measured and sometimes evaluated.

And that is the
primary reason music reproduction is not simply electrical and physical
engineering. Their is no way to measure *music*. Ultimately whether

the
music strikes our brain as right, or the brain tells us something is

amiss,
is not "objectively" measurable. The only way to objectify it is by
allowing humans to interpret it as music, and then to develop tests to

try
to record that *subjective* response in ways that can generate some
*objective* results in the statistical sense. And there is the rub.

It
demands context for the brain to interpret what is going on. Let me

give
you a non-musical example that I use here before...about a year and a

half
ago, I think.

Suppose you hear a split second of a car crash. That's all...half a

second
of indecipherable noise. You wouldn't even know what it was. However,

if
you heard a recording of street sounds, and auto approaching, a squeal

of
tires, and then the crash, you would know what you were hearing. And if

you
heard it through two different systems you could probably which one

sounded
"most real". However, if all your heard were two snippets of sound of

the
crash itself, my guess is your brain would be trying so hard to make

sense
of what you were hearing you couldn't evaluate anything in the way of

which
sounded most "real" because you didn't know what "real" was.


Here you go again, where is the requirement of only using a split
second for audio tests? No one on the DBT side has ever said that.


See my notes below to Tom

Something similar happens with music but even more complex. Because
scientist now know that the brain is hardwired to respond to this thing

we
call "music", both rhythmically and emotionally. Further the work done

by
Oohashi et al (The Journal of Neurophysiology Vol. 83 No. 6 June 2000,

pp.
3548-3558) indicated that this emotional response took place over time,

as
much as twenty seconds of time, from the time of the sound. Presumable

this
is the time it takes the brain to recognize and interpret the music as
pleasurable, unpleasurable, rhythmically coherent or incoherent, etc.


Again who said you couldn't use 20 second audio selections in
performing DBTs? Please let us know.


You don't even understand what I'm referring to. Suggest you read the
Oohashi article.

This fundamental fact means that you cannot measure "sound" and

determine
its impact as "music".


Never said you could, that is you inserting something I never said.


Then why are you taking on Ludovic's suggestion that abx in particular is
not the best instrument for evaluation audio components. After all, that is
*all* he has ever really argued.

The factors affecting how we respond to music are
apparently very subtle and "time-based" and "harmony-based" and not

static.
But a short burst comparison without much in the way of context for
recognition, relaxation, and response (which is the way most

short-interval
testing is done) tends to short-circuit the process. This is the

objection
must "subjectivists" have to ABX'ng in practice and why they question

"null
results" that seem so at odds with so many people's otherwise fairly

clear
perceptions of differences.


Please get off the short burst stuff, it has never been a requirement.


Again, read and understand first and then comment, thanks.

Oohashi et al indicate in the quoted article that they have confirmed

this
speculation. That is, they have used short-interval comparisons of

music,
and found "no difference" in ratings in line with accepted believe. But
when using "long-intervals" using the same stimuli and sequentially

monadic
ratings, the achieved statistically significant differences in response

to
the two stimuli.

You "amps is amps" people seem to want to ignore this finding, which is
pretty earthshaking and has nothing to do with whether you think the
"ultrasonic" portion of this test was done correctly or not, since
presumable the same stimulus was used in the precursor test (although to

be
fair this should have been better documented in the article rather than
treated as almost a passing reference). This finding alone, if
substantiated by others, would rule out much of the abx and possibly

most of
the dbt's done to date.


ABX especially does not require short bursts, and typically the
control of the switching is in the hands of the testee, so they can
use as long an interval as they wish. Please explain how that
invalidates any previous tests.


And if you are intent on hearing differences, as opposed to evaluating music
reproduction, the technique tends to lead you in that direction.

And I am not an "amps is amps" person, I know I have heard differences
between amps, preamps, CD players, etc. But I also know people are
programmed to find differences when none exist. As I've mentioned
before, I made a change to my system, remarked to myself how big a
change it made, only to find out I hadn't really made the change. All
it takes is doing that one time to realize how easy it is to be
mistaken in one's perceptions. I believe many of those on the DBT side
have had the same revelation before and it helped convince them of the
need for controls if one wants to be sure, just as it did to me.


We've all done that...it doesn't mean that all instances of sighted
listening are invalid. That's the logical error you folks make. Your
boolean should should be as follows (and for some here it is):

sighted listening can sometime lead to false positive differences
I am using sighted listening
Therefore, it is possible that differences are due to factors other than
sound.

Instead, in this newsgroup many tend to use different logic. It tends to go:

signted listening can sometimes lead to false positive differences
I am using sighted listening
Therefore, almost certainly I am imagining any differences I hear (because
we know better and because what you think you hear can't be possible, etc
etc etc)

And, Tom, before you say it, I know dbt'ng doesn't *have* to be done

that
way, but the fact is most of it has been done that way.


Only because those who use it find it's easiest to determine a
difference using short snippets. And yes, ABX tests have found
differences, they do not all have "no difference" reports.


Component evaluations of music reproduction? Documented and subject to a
rigorous methodological evaluation? If so, where? I'd feel a lot better
about the test which a goodly number of such results, as well as null
results. And, BTW, isn't that exactly what Ludovic and "Wheel" have been
requesting?

Back to the main point; evaluating components is *not* hearing

differences,
but evaluating how possible differences effect emotional and rhythmic
response from us as humans. There is a big difference. And the answer

to
the "there have to be differences fist" response is....how do you not

know
there aren't if the test itself tends to short circuit those responses.
This is why there have been requests for evidence of rigor in the

testing
and for validation of the abx and abc/hr testing themselves versus other
forms of testing (for example the sequential proto-monadic used by

Oohashi
et al which do purport to measure differences. it cannot just be

assumed
away.


Please explain how the test "short circuits" the response since the
only thing you've mentioned is the use of short snippets, a point I
believe I've shown is not valid.


You've asserted it is not valid, without reading Oohashi et al to understand
the delay mechanism and alternative means of measurement when it comes to
evaluating music.