I have the following worry about audio listening tests. Suppose the
meaningful variable is a property of an extended passage, not a short
snippet. Then a subject's failure to accurately distinguish or
re-identify may be due to an inability to retain the property in
memory.

I am thinking by way of contrast to visual examples. I just made two
prints of a photograph using different settings on my printer. I am
looking at the face of the subject and I can see that the contrast is
higher in one than in the other. That is a Gestalt property of a
meaningful chunk of the picture, not a property of a few pixels (cf.
notes). The difference with the musical case is that I can compare
the contrast of the two pictures directly, whereas in music no
immediate comparison is possible. At best I have to keep the property
in memory, and maybe the relevant variable is something not easily
retained.

Is the existing empirical confirmation for tests recommended in audio
based largely on visual data? If so, perhaps they rely on factors
that apply to the visual domain (i.e., possibility of immediate
comparison) but do not transfer easily to audio.

Or are there cases in the scientific literature in which the relevant
kinds of tests have been found valid to measure the detection of
Gestalt properties of aural, temporally extended signals?

Mark DeBellis wrote:
I have the following worry about audio listening tests. Suppose the
meaningful variable is a property of an extended passage, not a short
snippet. Then a subject's failure to accurately distinguish or
re-identify may be due to an inability to retain the property in
memory.

Then it's not audible. End of discussion.

bob

On 16 Jun 2005 03:14:23 GMT, wrote:

Mark DeBellis wrote:
I have the following worry about audio listening tests. Suppose the
meaningful variable is a property of an extended passage, not a short
snippet. Then a subject's failure to accurately distinguish or
re-identify may be due to an inability to retain the property in
memory.

Then it's not audible. End of discussion.

If you hear something but do not retain a memory of it (sufficient to
carry out a certain kind of test), you still heard it. No?

Mark DeBellis wrote:
On 16 Jun 2005 03:14:23 GMT, wrote:

Mark DeBellis wrote:
I have the following worry about audio listening tests. Suppose the
meaningful variable is a property of an extended passage, not a short
snippet. Then a subject's failure to accurately distinguish or
re-identify may be due to an inability to retain the property in
memory.

Then it's not audible. End of discussion.

If you hear something but do not retain a memory of it (sufficient to
carry out a certain kind of test), you still heard it. No?

In a sense, I suppose, but in that case you can't carry out any kind of
a comparison at all. So how could you be conscious of it under any
conditions? And if you can't be conscious of it under any conditions,
how can you say that you "heard" it?

Though I suspect you meant something slightly different, based on
another post, so I'll respond to that one.

bob

On 17 Jun 2005 03:06:00 GMT, wrote:

Mark DeBellis wrote:
On 16 Jun 2005 03:14:23 GMT, wrote:

Mark DeBellis wrote:
I have the following worry about audio listening tests. Suppose the
meaningful variable is a property of an extended passage, not a short
snippet. Then a subject's failure to accurately distinguish or
re-identify may be due to an inability to retain the property in
memory.

Then it's not audible. End of discussion.

If you hear something but do not retain a memory of it (sufficient to
carry out a certain kind of test), you still heard it. No?

In a sense, I suppose, but in that case you can't carry out any kind of
a comparison at all. So how could you be conscious of it under any
conditions? And if you can't be conscious of it under any conditions,
how can you say that you "heard" it?

I don't see how it follows from the fact that you're unable to do a
comparison at a later point that you weren't conscious of said
property when you experienced it.


Though I suspect you meant something slightly different, based on
another post, so I'll respond to that one.

bob

Mark DeBellis wrote:
On 16 Jun 2005 03:14:23 GMT, wrote:

If you hear something but do not retain a memory of it (sufficient to
carry out a certain kind of test), you still heard it. No?



I'm pretty sure I've mentioned this book here befo Daniel Dennett's
_Conciousness Explained_. Probably my favorite treatese on the physical
process of cognition & perception -- thought-provoking, challenging,
elucidating and funny to read! Highly recomended.

Anyway, I mention this book because, in a nutshell, according to
Dennett, the answer to your question is "No."

In a slightly bigger nutshell, Dennett goes on to explain (with far
more conviction & evidence than I could possibly muster in a newsgroup
posting) that there is often a significant & meaningful difference
between What We Perceived, and What We Think We Perceived.

On 17 Jun 2005 23:48:24 GMT, "Buster Mudd"
wrote:

Mark DeBellis wrote:
On 16 Jun 2005 03:14:23 GMT, wrote:

If you hear something but do not retain a memory of it (sufficient to
carry out a certain kind of test), you still heard it. No?



I'm pretty sure I've mentioned this book here befo Daniel Dennett's
_Conciousness Explained_. Probably my favorite treatese on the physical
process of cognition & perception -- thought-provoking, challenging,
elucidating and funny to read! Highly recomended.

Anyway, I mention this book because, in a nutshell, according to
Dennett, the answer to your question is "No."

That is an interesting book, and I do remember reading it a while
back, and I second your recommendation, but what exactly is the reason
to think "No"? There are cases all the time when people perceive
things and then forget them.


In a slightly bigger nutshell, Dennett goes on to explain (with far
more conviction & evidence than I could possibly muster in a newsgroup
posting) that there is often a significant & meaningful difference
between What We Perceived, and What We Think We Perceived.

True, but how does that difference play a role here?

Mark DeBellis wrote:
On 17 Jun 2005 23:48:24 GMT, "Buster Mudd"
wrote:

Mark DeBellis wrote:
On 16 Jun 2005 03:14:23 GMT, wrote:

If you hear something but do not retain a memory of it (sufficient to
carry out a certain kind of test), you still heard it. No?



I'm pretty sure I've mentioned this book here befo Daniel Dennett's
_Conciousness Explained_. Probably my favorite treatese on the physical
process of cognition & perception -- thought-provoking, challenging,
elucidating and funny to read! Highly recomended.

Anyway, I mention this book because, in a nutshell, according to
Dennett, the answer to your question is "No."

That is an interesting book, and I do remember reading it a while
back, and I second your recommendation, but what exactly is the reason
to think "No"?

Because "hearing" is a cognitive process; it takes place in the brain,
not in the ear. So if your brain tells you you didn't hear it, even if
soundwaves did strike your eardrum...and even (!) if at an earlier time
your brain told you that you did hear it...for all intents & purposes,
you didn't hear it. Saying "I heard it" is only useful if you can
access the perception in order to make subsequent discriminations.

There are cases all the time when people perceive
things and then forget them.

At which point any information they may have gleaned from perceiving
that thing is lost to them. Hence, the distinction between whether they
actually perceived it & then forgot it, or never perceived it in the
first place, is moot.



In a slightly bigger nutshell, Dennett goes on to explain (with far
more conviction & evidence than I could possibly muster in a newsgroup
posting) that there is often a significant & meaningful difference
between What We Perceived, and What We Think We Perceived.

True, but how does that difference play a role here?

It goes to the core of your initial question: How valid can an audio
test be if it's measuring the perception of phenomena which may not
actually exist?

"Buster Mudd" wrote:

Because "hearing" is a cognitive process; it takes place in the brain,
not in the ear. So if your brain tells you you didn't hear it, even if
soundwaves did strike your eardrum...and even (!) if at an earlier time
your brain told you that you did hear it...for all intents & purposes,
you didn't hear it. Saying "I heard it" is only useful if you can
access the perception in order to make subsequent discriminations.

I agree with the basic idea that perception is something that
influences behavior, but why does the behavior have to be restricted
to comparison and identification? Suppose a listener gives higher
approval ratings to one set of (blind) stimuli than another, without
ever trying to say which stimuli were the same and which were
different. This would be an influence on behavior, but of a weaker
sort than is required by the "can you reliably identify" type of test.


There are cases all the time when people perceive
things and then forget them.

At which point any information they may have gleaned from perceiving
that thing is lost to them. Hence, the distinction between whether they
actually perceived it & then forgot it, or never perceived it in the
first place, is moot.

Not if the information is still doing work somewhere in your cognitive
economy, even though it can't be brought to consciousness, or is not
specific enough to enable one to perform the identification task.

Mark

"Mark DeBellis" wrote in message
...
"Buster Mudd" wrote:

Because "hearing" is a cognitive process; it takes place in the brain,
not in the ear. So if your brain tells you you didn't hear it, even if
soundwaves did strike your eardrum...and even (!) if at an earlier time
your brain told you that you did hear it...for all intents & purposes,
you didn't hear it. Saying "I heard it" is only useful if you can
access the perception in order to make subsequent discriminations.

I agree with the basic idea that perception is something that
influences behavior, but why does the behavior have to be restricted
to comparison and identification? Suppose a listener gives higher
approval ratings to one set of (blind) stimuli than another, without
ever trying to say which stimuli were the same and which were
different. This would be an influence on behavior, but of a weaker
sort than is required by the "can you reliably identify" type of test.


Yet if 200 people do the same thing, you can apply statistical measures of
difference and determine with high accuracy whether or not subjectively
there is a difference, and if so, in what characteristics (assuming the
scalar data is pertinent to the differences heard). That is exactly the
kind of validation that is missing that would prove (or prove in the
negative) whether quick-switch, "short form" tests such as ABX can measure
the same thing.



There are cases all the time when people perceive
things and then forget them.

At which point any information they may have gleaned from perceiving
that thing is lost to them. Hence, the distinction between whether they
actually perceived it & then forgot it, or never perceived it in the
first place, is moot.

Not if the information is still doing work somewhere in your cognitive
economy, even though it can't be brought to consciousness, or is not
specific enough to enable one to perform the identification task.

Certainly. If you hear it again and respond the same way, it can influence
either favorably or unfavorably your reception to the music being played /
your evaluation of the system it is being played on. Thus most audiophiles
emphasis on long term listening.

Mark DeBellis wrote:
"Buster Mudd" wrote:

Because "hearing" is a cognitive process; it takes place in the brain,
not in the ear. So if your brain tells you you didn't hear it, even if
soundwaves did strike your eardrum...and even (!) if at an earlier time
your brain told you that you did hear it...for all intents & purposes,
you didn't hear it. Saying "I heard it" is only useful if you can
access the perception in order to make subsequent discriminations.

I agree with the basic idea that perception is something that
influences behavior, but why does the behavior have to be restricted
to comparison and identification?

It doesn't. You can easily do a DBT as, say, a preference test. If the
subject reports the same preference at a statistically significant
rate, we can assume that the two are different.

Suppose a listener gives higher
approval ratings to one set of (blind) stimuli than another, without
ever trying to say which stimuli were the same and which were
different. This would be an influence on behavior, but of a weaker
sort than is required by the "can you reliably identify" type of test.


There are cases all the time when people perceive
things and then forget them.

At which point any information they may have gleaned from perceiving
that thing is lost to them. Hence, the distinction between whether they
actually perceived it & then forgot it, or never perceived it in the
first place, is moot.

Not if the information is still doing work somewhere in your cognitive
economy, even though it can't be brought to consciousness, or is not
specific enough to enable one to perform the identification task.

But it isn't, because of our short aural memory for partial loudness
differences.

bob

Mark DeBellis wrote:
"Buster Mudd" wrote:

Hence, the distinction between whether they
actually perceived it & then forgot it, or never perceived it in the
first place, is moot.

Not if the information is still doing work somewhere in your cognitive
economy, even though it can't be brought to consciousness, or is not
specific enough to enable one to perform the identification task.



How would you go about *proving* that something was in someone's
"cognitive economy" if that someone was not conscious of that
something? How would you go about *proving* that something was in
someone's "cognitive economy" if that something could not enable that
someone to perform a task, any task?

Mark DeBellis wrote:
I have the following worry about audio listening tests. Suppose the
meaningful variable is a property of an extended passage, not a short
snippet. Then a subject's failure to accurately distinguish or
re-identify may be due to an inability to retain the property in
memory.

Nobody uses short snippets to do audio listening tests or comparisons.
We usually use a complete song or passage of an extended work.

I am thinking by way of contrast to visual examples. I just made two
prints of a photograph using different settings on my printer. I am
looking at the face of the subject and I can see that the contrast is
higher in one than in the other. That is a Gestalt property of a
meaningful chunk of the picture, not a property of a few pixels (cf.
notes). The difference with the musical case is that I can compare
the contrast of the two pictures directly, whereas in music no
immediate comparison is possible. At best I have to keep the property
in memory, and maybe the relevant variable is something not easily
retained.

Not true. You can perform rapid switching as often and as many as you
want. You level match the two sources so that the only difference you
hear is the sound quality differences between the two. Rapid switching
is the audio equivalent of a direct comparison.

Your complaint would apply only to long term comparisons, where you
listen first to a complete song on one source, then switch to the other
source and listen all over again.

Gary Eickmeier

Gary Eickmeier wrote:
Mark DeBellis wrote:
I have the following worry about audio listening tests. Suppose the
meaningful variable is a property of an extended passage, not a short
snippet. Then a subject's failure to accurately distinguish or
re-identify may be due to an inability to retain the property in
memory.

Nobody uses short snippets to do audio listening tests or comparisons.
We usually use a complete song or passage of an extended work.

I am thinking by way of contrast to visual examples. I just made two
prints of a photograph using different settings on my printer. I am
looking at the face of the subject and I can see that the contrast is
higher in one than in the other. That is a Gestalt property of a
meaningful chunk of the picture, not a property of a few pixels (cf.
notes). The difference with the musical case is that I can compare
the contrast of the two pictures directly, whereas in music no
immediate comparison is possible. At best I have to keep the
property in memory, and maybe the relevant variable is something not
easily retained.

Not true. You can perform rapid switching as often and as many as you
want. You level match the two sources so that the only difference you
hear is the sound quality differences between the two. Rapid switching
is the audio equivalent of a direct comparison.

Your complaint would apply only to long term comparisons, where you
listen first to a complete song on one source, then switch to the
other source and listen all over again.

Gary Eickmeier

I second Garys comment. Some additions:
There are ABX switchboxes available, I made one myself with relays to switch
between two speaker cables simultaneously on both ends. You can switch any
time as much as you like. The music or test signal (I use mostly pink noise)
is completely at your disposition, use what you feel gives the best results.
The faster and cleaner the switching action, the more subtle differences can
be discovered. If you are not into electronics it is better to get a ready
made box, to avoid any difference between the channels, like the sound of
the relais being different making/breaking or so.
--
ciao Ban
Bordighera, Italy

On 16 Jun 2005 23:53:16 GMT, "Ban" wrote:

Gary Eickmeier wrote:
Mark DeBellis wrote:
I have the following worry about audio listening tests. Suppose the
meaningful variable is a property of an extended passage, not a short
snippet. Then a subject's failure to accurately distinguish or
re-identify may be due to an inability to retain the property in
memory.

I second Garys comment. Some additions:
There are ABX switchboxes available, I made one myself with relays to switch
between two speaker cables simultaneously on both ends. You can switch any
time as much as you like.

Sorry I guess I didn't explain my idea very well. Suppose that in
order to perceive the relevant property a listener has to hear an
uninterrupted stretch of music from the same source. That is, suppose
the relevant property is not a property that belongs to any short
snippet of the signal but is rather a property that belongs only to a
whole, longer passage, say 5 mins. in length or a whole movement.
What I am thinking of here is the SACD vs. CD issue discussed on
another thread. I am wondering if the unit over which perception can
differ meaningfully can be an extended passage not a brief interval;
if so, my switching back and forth between SACD and CD would not be a
relevant test, because I would hear neither SACD nor CD as an unbroken
extended passage. I guess I am asking basically whether the existing
protocols for audio tests make room for the possibility that there can
be auditory perception of properties of longer, extended passages, and
are sufficient to measure such perception.

Perhaps the answer would be that there could not be a difference in
perceptible properties of longer passages without a detectable
difference in frequency response, which could be heard in quick-switch
tests; but is that obvious?

Mark

Mark DeBellis wrote:

Sorry I guess I didn't explain my idea very well. Suppose that in
order to perceive the relevant property a listener has to hear an
uninterrupted stretch of music from the same source. That is, suppose
the relevant property is not a property that belongs to any short
snippet of the signal but is rather a property that belongs only to a
whole, longer passage, say 5 mins. in length or a whole movement.
What I am thinking of here is the SACD vs. CD issue discussed on
another thread. I am wondering if the unit over which perception can
differ meaningfully can be an extended passage not a brief interval;
if so, my switching back and forth between SACD and CD would not be a
relevant test, because I would hear neither SACD nor CD as an unbroken
extended passage. I guess I am asking basically whether the existing
protocols for audio tests make room for the possibility that there can
be auditory perception of properties of longer, extended passages, and
are sufficient to measure such perception.

Yes. There's nothing that would make a DBT involving full 5-minute
samples invalid. However, there's also no reason to think they would
work better, as I noted yesterday.

(To be completely accurate, the protocols DO require that the subject
have the ability to switch any time he wants. But there is nothing that
requires him to switch more often than once every 5 minutes if he so
chooses.)

Perhaps the answer would be that there could not be a difference in
perceptible properties of longer passages without a detectable
difference in frequency response, which could be heard in quick-switch
tests; but is that obvious?

Yep. And you're more likely to notice it if you switch quickly and
frequently between choices.

bob

On 18 Jun 2005 02:27:00 GMT, wrote:

Mark DeBellis wrote:

Sorry I guess I didn't explain my idea very well. Suppose that in
order to perceive the relevant property a listener has to hear an
uninterrupted stretch of music from the same source. That is, suppose
the relevant property is not a property that belongs to any short
snippet of the signal but is rather a property that belongs only to a
whole, longer passage, say 5 mins. in length or a whole movement.
What I am thinking of here is the SACD vs. CD issue discussed on
another thread. I am wondering if the unit over which perception can
differ meaningfully can be an extended passage not a brief interval;
if so, my switching back and forth between SACD and CD would not be a
relevant test, because I would hear neither SACD nor CD as an unbroken
extended passage. I guess I am asking basically whether the existing
protocols for audio tests make room for the possibility that there can
be auditory perception of properties of longer, extended passages, and
are sufficient to measure such perception.

Yes. There's nothing that would make a DBT involving full 5-minute
samples invalid.

OK, then please explain to me where I'm going wrong. I am
hypothesizing that there are properties (1) that can only be perceived
over long stretches and (2) are not retained in memory. If there are
such properties, the kind of test I'm thinking of won't be sufficient
to measure the perception of them, because at the end of the second
5-minute sample, the subject won't remember the first one well enough
to make an accurate comparison. A test of this sort will not be
sensitive to the phenomenon. Please tell me why the reasons I have
given for my conclusion are not good ones.


However, there's also no reason to think they would
work better, as I noted yesterday.

(To be completely accurate, the protocols DO require that the subject
have the ability to switch any time he wants. But there is nothing that
requires him to switch more often than once every 5 minutes if he so
chooses.)

Perhaps the answer would be that there could not be a difference in
perceptible properties of longer passages without a detectable
difference in frequency response, which could be heard in quick-switch
tests; but is that obvious?

Yep.

Well, it's not obvious to me, so if you could give me some indication
why I should think it's true, that would be most appreciated!

Mark

"Mark DeBellis" wrote in message
...
On 16 Jun 2005 23:53:16 GMT, "Ban" wrote:

Gary Eickmeier wrote:
Mark DeBellis wrote:
I have the following worry about audio listening tests. Suppose the
meaningful variable is a property of an extended passage, not a short
snippet. Then a subject's failure to accurately distinguish or
re-identify may be due to an inability to retain the property in
memory.

I second Garys comment. Some additions:
There are ABX switchboxes available, I made one myself with relays to
switch
between two speaker cables simultaneously on both ends. You can switch any
time as much as you like.

Sorry I guess I didn't explain my idea very well. Suppose that in
order to perceive the relevant property a listener has to hear an
uninterrupted stretch of music from the same source. That is, suppose
the relevant property is not a property that belongs to any short
snippet of the signal but is rather a property that belongs only to a
whole, longer passage, say 5 mins. in length or a whole movement.
What I am thinking of here is the SACD vs. CD issue discussed on
another thread. I am wondering if the unit over which perception can
differ meaningfully can be an extended passage not a brief interval;
if so, my switching back and forth between SACD and CD would not be a
relevant test, because I would hear neither SACD nor CD as an unbroken
extended passage. I guess I am asking basically whether the existing
protocols for audio tests make room for the possibility that there can
be auditory perception of properties of longer, extended passages, and
are sufficient to measure such perception.

Perhaps the answer would be that there could not be a difference in
perceptible properties of longer passages without a detectable
difference in frequency response, which could be heard in quick-switch
tests; but is that obvious?


There is a very simple, very powerful way to determine this. But it is not
practical or possible for one individual. It is called monadic testing. It
requires listening to the segment of music, and rating that musical
reproduction *immediately afterwards* using a series of rating criteria.
Such criteria might include, for example, a five point scale ranging from:
"bass sounded extrememly punchy" to "bass sounded flabby and undynamic".
When hundreds of people do this, statistics can be applied to determine if
there are in fact perceivable differences, and if so, on what criteria.

If I were Harmon Industries, I might design and sponsor such a test on
occasion. Frankly, Sony blew an opportunity to do such a test (it would be
expensive) for their SACD launch. Imagine if the introductory campaign had
included "proof" that SACD sounded better. We'd now have a viable second
format.

If I were the AES, I might sponsor such a test as a "control test" for
single-person tests such as the much bally-hooed ABX test, to advance the
state of the art..

But for a given individual it is not a practical test.

On 16 Jun 2005 03:14:56 GMT, Gary Eickmeier
wrote:

Mark DeBellis wrote:
I have the following worry about audio listening tests. Suppose the
meaningful variable is a property of an extended passage, not a short
snippet. Then a subject's failure to accurately distinguish or
re-identify may be due to an inability to retain the property in
memory.

Nobody uses short snippets to do audio listening tests or comparisons.
We usually use a complete song or passage of an extended work.

I am thinking by way of contrast to visual examples. I just made two
prints of a photograph using different settings on my printer. I am
looking at the face of the subject and I can see that the contrast is
higher in one than in the other. That is a Gestalt property of a
meaningful chunk of the picture, not a property of a few pixels (cf.
notes). The difference with the musical case is that I can compare
the contrast of the two pictures directly, whereas in music no
immediate comparison is possible. At best I have to keep the property
in memory, and maybe the relevant variable is something not easily
retained.

Not true. You can perform rapid switching as often and as many as you
want.

OK but I am saying, suppose the meaningful variable is a property of
an extended passage. So you have to listen to an uninterrupted
passage in order to perceive the property. Switching back and forth
will defeat the purpose, yes?

Mark

Mark DeBellis wrote:
OK but I am saying, suppose the meaningful variable is a property of
an extended passage. So you have to listen to an uninterrupted
passage in order to perceive the property. Switching back and forth
will defeat the purpose, yes?

Yeah, but. First, the problem, if it were a problem, could easily be
solved by listening to longer passages. No one's ever heard differences
between competent amps/cables doing it that way, either.

Second, the research demonstrates pretty clearly that our memory for
subtle sonic differences is very limited. In other words, contrary to
your conjecture, switching back and forth quickly and frequently really
is more effective.

bob

On 17 Jun 2005 03:11:07 GMT, wrote:

Mark DeBellis wrote:
OK but I am saying, suppose the meaningful variable is a property of
an extended passage. So you have to listen to an uninterrupted
passage in order to perceive the property. Switching back and forth
will defeat the purpose, yes?

Yeah, but. First, the problem, if it were a problem, could easily be
solved by listening to longer passages. No one's ever heard differences
between competent amps/cables doing it that way, either.

It would not solve the problem because once you had listened to the
first passage you would have to remember the property for the duration
of the second passage, and I am hypothesizing that you don't have
reliable memory for that. That is the problem.

FWIW, here I am thinking of SACD vs. CD rather than amps or cables. I
don't know if it makes a difference, but the intuition is about music
not white noise (say).


Second, the research demonstrates pretty clearly that our memory for
subtle sonic differences is very limited. In other words, contrary to
your conjecture, switching back and forth quickly and frequently really
is more effective.

Is the research that demonstrates this based entirely on the tests
that I am saying would not be sensitive to such possibilities? Isn't
that a circular argument? If not, what is the relevant research?

Mark

Mark DeBellis wrote:

It would not solve the problem because once you had listened to the
first passage you would have to remember the property for the duration
of the second passage, and I am hypothesizing that you don't have
reliable memory for that. That is the problem.

OK, so let me get this straight: You listen to one component, hear
certain properties, then listen to another component, and hear certain
other properties, but by the time it's all over with you can't remember
which was which? This pretty much dooms any listening test, doesn't it?
Not sure I see the point of your question.

Gary Eickmeier

Mark DeBellis wrote:
On 17 Jun 2005 03:11:07 GMT, wrote:

Mark DeBellis wrote:
OK but I am saying, suppose the meaningful variable is a property of
an extended passage. So you have to listen to an uninterrupted
passage in order to perceive the property. Switching back and forth
will defeat the purpose, yes?

Yeah, but. First, the problem, if it were a problem, could easily be
solved by listening to longer passages. No one's ever heard differences
between competent amps/cables doing it that way, either.

It would not solve the problem because once you had listened to the
first passage you would have to remember the property for the duration
of the second passage, and I am hypothesizing that you don't have
reliable memory for that. That is the problem.

Then how do you know it's a meaningful variable?

FWIW, here I am thinking of SACD vs. CD rather than amps or cables. I
don't know if it makes a difference, but the intuition is about music
not white noise (say).


Second, the research demonstrates pretty clearly that our memory for
subtle sonic differences is very limited. In other words, contrary to
your conjecture, switching back and forth quickly and frequently really
is more effective.

Is the research that demonstrates this based entirely on the tests
that I am saying would not be sensitive to such possibilities? Isn't
that a circular argument? If not, what is the relevant research?

It's based on tests of human hearing. Your ability to remember partial
loudness differences lasts a couple of seconds, tops. You are
speculating that there exists something that violates this established
fact. What is it, and how do you know?

bob

Mark DeBellis wrote:

OK but I am saying, suppose the meaningful variable is a property of
an extended passage. So you have to listen to an uninterrupted
passage in order to perceive the property. Switching back and forth
will defeat the purpose, yes?

I would say this is a false premise. But perhaps you could give an
example of a meaningful variable that is a property of a longer passage.

Gary Eickmeier

A couple of further ideas to toss out, from an onlooker's perspective
of course.

Quick-switch tests are said to be the most sensitive, therefore best,
yes? Because they permit finer discriminations. An observation: the
ultimate purpose of an audio test is not discrimination per se. That
is, it's not as if the job that has to be performed here is to
discriminate two sources if they can be, to do the best job of
discrimination we can, as if that were the real goal. The real purpose
of the test is rather to find out what information is available to the
listener in the context of use, or perhaps to estimate an upper bound
on that information.

It is possible that two sources in the ordinary context of use do not
present different information to the listener, even if there are ways
to set up testing situations (e.g., at higher volume) where a person
could discriminate the sources. All well and good if we do, but it's
not like having a test that permits such discrimination is a valuable
achievement in itself; what we are basically interested in is making
sure that if there are differences of information presented in the
ordinary context of use, then they will show up and get discriminated
in the test.

Question: for all the resolving power quick-switch tests have, for all
the power they have to put the stimulus under a microscope and discern
small differences of detail, are there certain sorts of properties they
are *not* so good at picking up? Is there perhaps a forest-for-trees
phenomenon lurking somewhere out there?

Here's an off the cuff example. Suppose I have two digital photographs
that are identical except that one is 1.01 the size of the other.
First I compare them (this is the analogue of the quick-switch test) by
comparing small portions of one with the other. The comparison is set
up in such a way that when I compare a square portion of one with a
square portion of the other, one of them is 1.01 as large as the other.
However, I cannot see the difference because these are small areas and
the difference in size is below my threshold of discrimination.

However, when I compare the wholes I can see the difference in size,
because the difference is now greater than the threshold, since the
whole is much larger than any of those parts.

An auditory example would be tempo. Suppose I am listening to two
sources, where the only difference is that one of them has a speed of
1.01 times the other. If I listen to short excerpts any difference is
below the just-noticeable-difference, but if the whole example is the
Ring cycle, I will notice that one finishes before dark and the other
doesn't, I get hungry during one but not the other, etc.

So even if quick-switch tests, on balance, are the most sensitive, that
doesn't mean there can't be things out there that don't get caught in
their net (though they may be detectable in other ways).

To come back to the SACD/CD example, my concern is whether, even if the
quick-switch test were a "null," there could be differences that the
test does not do a good job of proving the existence of. Rather than
feel assured that science tells us there could not be such differences,
it seems to me pretty apparent that every test has its limitations.

Sound plausible?

Mark

Mark DeBellis wrote:
A couple of further ideas to toss out, from an onlooker's perspective
of course.

Quick-switch tests are said to be the most sensitive, therefore best,
yes? Because they permit finer discriminations. An observation: the
ultimate purpose of an audio test is not discrimination per se.

No, but if you can't discriminate between two things, then the
differences between them are irrelevant.

That
is, it's not as if the job that has to be performed here is to
discriminate two sources if they can be, to do the best job of
discrimination we can, as if that were the real goal. The real purpose
of the test is rather to find out what information is available to the
listener in the context of use, or perhaps to estimate an upper bound
on that information.

Well, we know that. That's what the science of psychoacoustics is all
about. Check it out sometime.

It is possible that two sources in the ordinary context of use do not
present different information to the listener, even if there are ways
to set up testing situations (e.g., at higher volume) where a person
could discriminate the sources. All well and good if we do, but it's
not like having a test that permits such discrimination is a valuable
achievement in itself; what we are basically interested in is making
sure that if there are differences of information presented in the
ordinary context of use, then they will show up and get discriminated
in the test.

Question: for all the resolving power quick-switch tests have, for all
the power they have to put the stimulus under a microscope and discern
small differences of detail, are there certain sorts of properties they
are *not* so good at picking up? Is there perhaps a forest-for-trees
phenomenon lurking somewhere out there?

No there is not, according to all experts in the field. Or do you think
you know more than the experts?

Here's an off the cuff example. Suppose I have two digital photographs
that are identical except that one is 1.01 the size of the other.
First I compare them (this is the analogue of the quick-switch test) by
comparing small portions of one with the other. The comparison is set
up in such a way that when I compare a square portion of one with a
square portion of the other, one of them is 1.01 as large as the other.
However, I cannot see the difference because these are small areas and
the difference in size is below my threshold of discrimination.

However, when I compare the wholes I can see the difference in size,
because the difference is now greater than the threshold, since the
whole is much larger than any of those parts.

Irrelevant and off-point visual analogy. Visual analogies don't work.
Ever.

An auditory example would be tempo. Suppose I am listening to two
sources, where the only difference is that one of them has a speed of
1.01 times the other. If I listen to short excerpts any difference is
below the just-noticeable-difference, but if the whole example is the
Ring cycle, I will notice that one finishes before dark and the other
doesn't, I get hungry during one but not the other, etc.

But you're not discriminating between the two by listening to them.
You're discriminating between them by looking at the clock. (And I
don't know what the threshold is for speed variation, but at some point
you really would be able to distinguish between them in a standard
DBT.)

So even if quick-switch tests, on balance, are the most sensitive, that
doesn't mean there can't be things out there that don't get caught in
their net (though they may be detectable in other ways).

So far you haven't come up with a single one. That's because there
aren't any.

To come back to the SACD/CD example, my concern is whether, even if the
quick-switch test were a "null," there could be differences that the
test does not do a good job of proving the existence of. Rather than
feel assured that science tells us there could not be such differences,
it seems to me pretty apparent that every test has its limitations.

Sound plausible?

No. It sounds like you're grasping at straws because you don't like
what the science is telling you. If you live in Kansas, I suggest you
run for the state board of ed.

bob

Mark DeBellis wrote:

An auditory example would be tempo. Suppose I am listening to two
sources, where the only difference is that one of them has a speed of
1.01 times the other. If I listen to short excerpts any difference is
below the just-noticeable-difference, but if the whole example is the
Ring cycle, I will notice that one finishes before dark and the other
doesn't, I get hungry during one but not the other, etc.

So even if quick-switch tests, on balance, are the most sensitive, that
doesn't mean there can't be things out there that don't get caught in
their net (though they may be detectable in other ways).

To come back to the SACD/CD example, my concern is whether, even if the
quick-switch test were a "null," there could be differences that the
test does not do a good job of proving the existence of. Rather than
feel assured that science tells us there could not be such differences,
it seems to me pretty apparent that every test has its limitations.

Sound plausible?

You can't do a "quick switch" test with two sources that run at
different speeds because you can't synchronize them, which would be a
dead giveaway in itself, so that is a bad example.

If you want to use that example, you will have to listen first to one,
then the other, in its entirety, then decide if the speed difference is
audible. If so, then do a blind series, listening to a known version,
then to a randomly chosen one, and decide whether it is the same or
different. In this manner you will eventually arrive at a number for a
speed differential that is at the audible threshold. That is the basic
idea of how audio research is done. You may find that speed differences
of 1.01 will be inaudible to most, but audible to some with perfect
pitch. If this is interesting enough a question for you, then do the
research and report it.

Gary Eickmeier

Gary Eickmeier wrote:

Mark DeBellis wrote:
OK but I am saying, suppose the meaningful variable is a property of
an extended passage. So you have to listen to an uninterrupted
passage in order to perceive the property. Switching back and forth
will defeat the purpose, yes?

I would say this is a false premise. But perhaps you could give an
example of a meaningful variable that is a property of a longer passage.

I missed your post until now because, for some reason, it didn't
download (I'm using Free Agent) from my news server.

An example of a property that belongs to a temporally extended passage
without belonging to short slices of it is being a descending C major
scale, one octave long. That is a property a listener can perceive
the passage as having, but it is a property is one that belongs to the
whole, not short parts.

Another perceivable property that belongs to a temporal whole is the
property, belonging to a spoken sentence, of being syntactically well
formed.

Mark

Sorry, one of my previous posts had a couple of extraneous words in
one place; here is a corrected version.

Gary Eickmeier wrote:

Mark DeBellis wrote:
OK but I am saying, suppose the meaningful variable is a property of
an extended passage. So you have to listen to an uninterrupted
passage in order to perceive the property. Switching back and forth
will defeat the purpose, yes?

I would say this is a false premise. But perhaps you could give an
example of a meaningful variable that is a property of a longer passage.

I missed your post until now because, for some reason, it didn't
download (I'm using Free Agent) from my news server.

An example of a property that belongs to a temporally extended passage
without belonging to short slices of it is being a descending C major
scale, one octave long. That is a property a listener can perceive
the passage as having, but it is a property that belongs to the whole,
not short parts.

Another perceivable property that belongs to a temporal whole is the
property, belonging to a spoken sentence, of being syntactically well
formed.

Mark

Mark DeBellis wrote:
I have the following worry about audio listening tests. Suppose the
meaningful variable is a property of an extended passage, not a short
snippet. Then a subject's failure to accurately distinguish or
re-identify may be due to an inability to retain the property in
memory.


You have a very good point. It's a shame that so many people here
responded only to try to show how you are wrong.

Some very important musical percepts correspond to diffuse patterns in
the music; form, for example. These patterns work on most listeners;
but generally it is only the more experienced listeners who have become
*conscious* of how these patterns work.

Actually even in local patterns--the local beat, or timbre--it takes
time and the proper context to stimulate the corresponding musical
precepts. And listening tests that compare only "short snippets," as
you say, don't provide that time and context.

A test subject will certainly have difficulty remembering these
percepts. Consider that animals and humans need to have a good memory
for objects in the world that correspond to direct sensation. The more
abstract the percept becomes, the less need evolution had to equip
creatures with memory for it. There's some need to remember internal
states like emotions; less need to remember something more abstract
like the degree and quality of the emotion.

Another difficulty comes in the subject's attempt to conceptualize and
then externalize the percept. To conceptualize: to label the
experience. And to externalize: to convey that label to the
experimenter. Zen meditators know, for example, that conceptualizing an
experience collapses it into a limited number of states.

In the test subject, lack of consciousness of the diffuse percepts
works against being able to identify them with confidence; the demand
of the experiment that the experience be conceptualized provides
further difficultues; and the clumsiness of the experimentor with
regard to how the test "paradigm" influences the result, all work
against the validity of the result.

Helen