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Validity of audio tests

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Anonymous
a b } Memory
June 16, 2005 4:01:33 AM

Archived from groups: rec.audio.high-end (More info?)

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?

More about : validity audio tests

Anonymous
a b } Memory
June 16, 2005 7:14:23 AM

Archived from groups: rec.audio.high-end (More info?)

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
Anonymous
a b } Memory
June 16, 2005 7:14:56 AM

Archived from groups: rec.audio.high-end (More info?)

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
Related resources
June 17, 2005 3:53:16 AM

Archived from groups: rec.audio.high-end (More info?)

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
Anonymous
a b } Memory
June 17, 2005 3:54:27 AM

Archived from groups: rec.audio.high-end (More info?)

On 16 Jun 2005 03:14:56 GMT, Gary Eickmeier <geickmei@tampabay.rr.com>
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
Anonymous
a b } Memory
June 17, 2005 3:54:47 AM

Archived from groups: rec.audio.high-end (More info?)

On 16 Jun 2005 03:14:23 GMT, nabob33@hotmail.com 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?
Anonymous
a b } Memory
June 17, 2005 7:06:00 AM

Archived from groups: rec.audio.high-end (More info?)

Mark DeBellis wrote:
> On 16 Jun 2005 03:14:23 GMT, nabob33@hotmail.com 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
Anonymous
a b } Memory
June 17, 2005 7:11:07 AM

Archived from groups: rec.audio.high-end (More info?)

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
Anonymous
a b } Memory
June 17, 2005 7:12:37 AM

Archived from groups: rec.audio.high-end (More info?)

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
Anonymous
a b } Memory
June 18, 2005 3:47:33 AM

Archived from groups: rec.audio.high-end (More info?)

On 16 Jun 2005 23:53:16 GMT, "Ban" <bansuri@web.de> 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
Anonymous
a b } Memory
June 18, 2005 3:48:24 AM

Archived from groups: rec.audio.high-end (More info?)

Mark DeBellis wrote:
> On 16 Jun 2005 03:14:23 GMT, nabob33@hotmail.com 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 before: 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.
Anonymous
a b } Memory
June 18, 2005 6:27:00 AM

Archived from groups: rec.audio.high-end (More info?)

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
Anonymous
a b } Memory
June 18, 2005 6:27:43 AM

Archived from groups: rec.audio.high-end (More info?)

"Mark DeBellis" <mad1@columbia.edu> wrote in message
news:D 8vnel0fk8@news4.newsguy.com...
> On 16 Jun 2005 23:53:16 GMT, "Ban" <bansuri@web.de> 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.
Anonymous
a b } Memory
June 18, 2005 8:38:14 PM

Archived from groups: rec.audio.high-end (More info?)

On 17 Jun 2005 03:06:00 GMT, nabob33@hotmail.com wrote:

>Mark DeBellis wrote:
>> On 16 Jun 2005 03:14:23 GMT, nabob33@hotmail.com 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
Anonymous
a b } Memory
June 18, 2005 8:39:11 PM

Archived from groups: rec.audio.high-end (More info?)

On 17 Jun 2005 03:11:07 GMT, nabob33@hotmail.com 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
Anonymous
a b } Memory
June 18, 2005 8:40:11 PM

Archived from groups: rec.audio.high-end (More info?)

On 17 Jun 2005 23:48:24 GMT, "Buster Mudd" <mr_furious@mail.com>
wrote:

>Mark DeBellis wrote:
>> On 16 Jun 2005 03:14:23 GMT, nabob33@hotmail.com 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 before: 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?
Anonymous
a b } Memory
June 18, 2005 8:40:47 PM

Archived from groups: rec.audio.high-end (More info?)

On 18 Jun 2005 02:27:00 GMT, nabob33@hotmail.com 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
Anonymous
a b } Memory
June 19, 2005 2:46:39 AM

Archived from groups: rec.audio.high-end (More info?)

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
Anonymous
a b } Memory
June 19, 2005 2:47:38 AM

Archived from groups: rec.audio.high-end (More info?)

Mark DeBellis wrote:
> On 17 Jun 2005 03:11:07 GMT, nabob33@hotmail.com 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
Anonymous
a b } Memory
June 19, 2005 2:48:42 AM

Archived from groups: rec.audio.high-end (More info?)

Mark DeBellis wrote:
> On 18 Jun 2005 02:27:00 GMT, nabob33@hotmail.com wrote:
> >
> >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

This is where you're going wrong. You are NOT hypothesizing. You are
engaging in idle speculation. "There might be something" is not a
hypothesis. If you can tell us what you think that something is, and
give us some reason to believe it might be a factor, then you have a
hypothesis.

> that there are properties (1) that can only be perceived
> over long stretches and (2) are not retained in memory.

Aren't these two things mutually contradictory? Certainly you are
relying on memory when you perceive something over long stretches. And,
to repeat myself, what is it? We're still waiting.

> 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!

Can you name some sonic distinction that isn't a partial loudness
difference?

bob
Anonymous
a b } Memory
June 20, 2005 7:24:36 AM

Archived from groups: rec.audio.high-end (More info?)

On 18 Jun 2005 22:46:39 GMT, Gary Eickmeier <geickmei@tampabay.rr.com>
wrote:

>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.

It is that the test would be inadequate to measure the detection of
said properties.

The background to this is that I said I thought SACD sounded better
than CD, and Chung suggested that I try a simple blind test, to see if
I could reliably identify which was SACD and which was CD (after
matching levels; SACD and CD layers of same disc). Indeed I could
not, at least on one set of trials. Should the conclusion be that
SACD sounds the same as CD? Or is it possible that the test I applied
is inadequate in some way? How *could* it be possible that the test
is inadequate? My question is basically an attempt to explain how
that might be. Suppose when I am listening to recorded music (1) I
hear properties of temporally extended passages and (2) I can't retain
a memory of those properties long enough to make a comparison, if at
all. Then I could have perceived different things, although this
difference would not show up in the kind of test I performed.

Mark
Anonymous
a b } Memory
June 21, 2005 3:57:14 AM

Archived from groups: rec.audio.high-end (More info?)

Mark DeBellis wrote:
> On 17 Jun 2005 23:48:24 GMT, "Buster Mudd" <mr_furious@mail.com>
> wrote:
>
> >Mark DeBellis wrote:
> >> On 16 Jun 2005 03:14:23 GMT, nabob33@hotmail.com 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 before: 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?
Anonymous
a b } Memory
June 21, 2005 3:58:31 AM

Archived from groups: rec.audio.high-end (More info?)

Mark DeBellis wrote:
> On 18 Jun 2005 22:46:39 GMT, Gary Eickmeier <geickmei@tampabay.rr.com>
> wrote:
>
> >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.
>
> It is that the test would be inadequate to measure the detection of
> said properties.
>
> The background to this is that I said I thought SACD sounded better
> than CD, and Chung suggested that I try a simple blind test, to see if
> I could reliably identify which was SACD and which was CD (after
> matching levels; SACD and CD layers of same disc). Indeed I could
> not, at least on one set of trials. Should the conclusion be that
> SACD sounds the same as CD? Or is it possible that the test I applied
> is inadequate in some way? How *could* it be possible that the test
> is inadequate? My question is basically an attempt to explain how
> that might be. Suppose when I am listening to recorded music (1) I
> hear properties of temporally extended passages and (2) I can't retain
> a memory of those properties long enough to make a comparison, if at
> all. Then I could have perceived different things, although this
> difference would not show up in the kind of test I performed.

IOW, you did a test, you didn't like the result, so now you're
demanding that we give you some basis for rejecting the result of the
test.

The test is adequate, assuming you did it with reasonable care. That's
why scientists have used it to test just about everything we know about
hearing. Why should a test become inadequate just because some hobbyist
wants to believe something that isn't true?

bob
Anonymous
a b } Memory
June 21, 2005 6:51:45 AM

Archived from groups: rec.audio.high-end (More info?)

<nabob33@hotmail.com> wrote in message news:D 97l770m18@news3.newsguy.com...
> Mark DeBellis wrote:
>> On 18 Jun 2005 22:46:39 GMT, Gary Eickmeier <geickmei@tampabay.rr.com>
>> wrote:
>>
>> >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.
>>
>> It is that the test would be inadequate to measure the detection of
>> said properties.
>>
>> The background to this is that I said I thought SACD sounded better
>> than CD, and Chung suggested that I try a simple blind test, to see if
>> I could reliably identify which was SACD and which was CD (after
>> matching levels; SACD and CD layers of same disc). Indeed I could
>> not, at least on one set of trials. Should the conclusion be that
>> SACD sounds the same as CD? Or is it possible that the test I applied
>> is inadequate in some way? How *could* it be possible that the test
>> is inadequate? My question is basically an attempt to explain how
>> that might be. Suppose when I am listening to recorded music (1) I
>> hear properties of temporally extended passages and (2) I can't retain
>> a memory of those properties long enough to make a comparison, if at
>> all. Then I could have perceived different things, although this
>> difference would not show up in the kind of test I performed.
>
> IOW, you did a test, you didn't like the result, so now you're
> demanding that we give you some basis for rejecting the result of the
> test.
>
> The test is adequate, assuming you did it with reasonable care. That's
> why scientists have used it to test just about everything we know about
> hearing. Why should a test become inadequate just because some hobbyist
> wants to believe something that isn't true?

Sorry to sound like a broken record, but since you assert this constantly I
can only do the same in response....the testing you favor has never been
validated for the open-ended evaluation of reproduced music. Period. If it
had been and could be demonstrated to have been so, it would be widely used
and accepted by most every audiophile. The fact that it has not been, is
not accepted, and flies in the face of so much otherwise different consensus
means that to continue asserting it as you do, is an act of faith, nothing
else.
Anonymous
a b } Memory
June 22, 2005 4:07:17 AM

Archived from groups: rec.audio.high-end (More info?)

Gary Eickmeier <geickmei@tampabay.rr.com> 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
Anonymous
a b } Memory
June 22, 2005 4:08:50 AM

Archived from groups: rec.audio.high-end (More info?)

nabob33@hotmail.com wrote:

>Mark DeBellis wrote:
>> On 17 Jun 2005 03:11:07 GMT, nabo...@hotmail.com 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?
>

I'm not claiming to know that. I'm saying that *if* such properties
exist, certain tests would not be capable of demonstrating that people
perceive them. It is a point about whether the methodology is
sensitive to a certain class of properties.

It is not contrary to "established fact" to assert that properties of
temporally extended wholes exist and can be perceived. That is
demonstrated every time you recognize a melody.

Mark
Anonymous
a b } Memory
June 22, 2005 4:10:10 AM

Archived from groups: rec.audio.high-end (More info?)

"Buster Mudd" <mr_furious@mail.com> 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
Anonymous
a b } Memory
June 22, 2005 4:13:41 AM

Archived from groups: rec.audio.high-end (More info?)

When I said the other day that audio subjectivism is the rejection of
the scientific method, this is what I meant:

Harry Lavo wrote:
>
> Sorry to sound like a broken record, but since you assert this constantly I
> can only do the same in response....the testing you favor has never been
> validated for the open-ended evaluation of reproduced music. Period. If it
> had been and could be demonstrated to have been so, it would be widely used
> and accepted by most every audiophile. The fact that it has not been, is
> not accepted, and flies in the face of so much otherwise different consensus
> means that to continue asserting it as you do, is an act of faith, nothing
> else.

To believe this, one must ignore reams of scientific data that conflict
with what you believe. In particular, one must assert, against all
evidence, that human hearing operates differently when listening to
reproduced music than it does at all other times, and that generations
of scientists have just been deluding themselves.

This is how Creation Science operates. Let's hope the audio field never
sinks so low.

bob
Anonymous
a b } Memory
June 22, 2005 4:14:14 AM

Archived from groups: rec.audio.high-end (More info?)

nabob33@hotmail.com wrote:
> Mark DeBellis wrote:
> > On 17 Jun 2005 03:11:07 GMT, nabob33@hotmail.com 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?



It seems his point is that yo don't know it isn't either.



>
> > 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.




Now that is interesting given that small barely audible level
differences can lead one to form a prefernce. How can that be?





You are
> speculating that there exists something that violates this established
> fact. What is it, and how do you know?





How do you explain the fact that small level diferences can lead to
prefeences if we can't remember them in our comparisons?




Scott Wheeler
Anonymous
a b } Memory
June 22, 2005 4:15:16 AM

Archived from groups: rec.audio.high-end (More info?)

Harry Lavo said:

.....the testing you favor has never been
>validated for the open-ended evaluation of reproduced music. Period.

Which evalutaion method that you approve of has been so validated?
What did the BBC use when they did their ABX comparisons for the
purpose of upgrading their speakers?

> If it
>had been and could be demonstrated to have been so, it would be widely used
>and accepted by most every audiophile.

The fact that double blind level matched comparisons are the standard
for those doing the serious research on all other forms of sound hasn't
seemed to convince audiophiles that it is valid, so, it would seem that
many of them simply refuse to accept what is known, probably because it
doesn't give the results that they believe they should get.

>The fact that it has not been, is
>not accepted, and flies in the face of so much otherwise different consensus
>means that to continue asserting it as you do, is an act of faith, nothing
>else.

And accepting less reliable, non-bias controlled tests, is not?

The problem is not consensus, since clearly audiophiles are in the
minority when it comes to ABX and it's reliability.
Anonymous
a b } Memory
June 22, 2005 4:15:51 AM

Archived from groups: rec.audio.high-end (More info?)

Mark DeBellis <mad1@columbia.edu> wrote:
....
> The background to this is that I said I thought SACD sounded better
> than CD, and Chung suggested that I try a simple blind test, to see if
> I could reliably identify which was SACD and which was CD (after
> matching levels; SACD and CD layers of same disc). Indeed I could
> not, at least on one set of trials. Should the conclusion be that
> SACD sounds the same as CD? Or is it possible that the test I applied
> is inadequate in some way? How *could* it be possible that the test
> is inadequate? My question is basically an attempt to explain how
> that might be. ...

Another possibility is suggested by an informal experiment on smells
that I did on myself. I took a selection of spices that were all
in the same type of bottle, closed my eyes, shuffled the bottles
around, and opened and sniffed them one by one, trying to identify
the spice by name. I was sure I could do it but was quite amazed to
discover that I couldn't do it at all. With my eyes closed, I could
tell the differences perfectly well, but I just couldn't connect the
names with the smells.

So I think it's *possible* that in unsighted comparisons, the part
of the brain that does symbolic analysis and associated judgment
is not in perfect communication with other parts.
--
Greg Lee <greg@ling.lll.hawaii.edu>
Anonymous
a b } Memory
June 22, 2005 4:21:21 AM

Archived from groups: rec.audio.high-end (More info?)

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
Anonymous
a b } Memory
June 22, 2005 4:28:26 AM

Archived from groups: rec.audio.high-end (More info?)

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

Gary Eickmeier <geickmei@tampabay.rr.com> 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
Anonymous
a b } Memory
June 22, 2005 7:03:55 AM

Archived from groups: rec.audio.high-end (More info?)

"Mark DeBellis" <mad1@columbia.edu> wrote in message
news:D 9aa9202ead@news4.newsguy.com...
> "Buster Mudd" <mr_furious@mail.com> 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.
Anonymous
a b } Memory
June 22, 2005 7:04:21 AM

Archived from groups: rec.audio.high-end (More info?)

<nabob33@hotmail.com> wrote in message news:D 9aafl02eej@news4.newsguy.com...
> When I said the other day that audio subjectivism is the rejection of
> the scientific method, this is what I meant:
>
> Harry Lavo wrote:
>>
>> Sorry to sound like a broken record, but since you assert this constantly
>> I
>> can only do the same in response....the testing you favor has never been
>> validated for the open-ended evaluation of reproduced music. Period. If
>> it
>> had been and could be demonstrated to have been so, it would be widely
>> used
>> and accepted by most every audiophile. The fact that it has not been, is
>> not accepted, and flies in the face of so much otherwise different
>> consensus
>> means that to continue asserting it as you do, is an act of faith,
>> nothing
>> else.
>
> To believe this, one must ignore reams of scientific data that conflict
> with what you believe. In particular, one must assert, against all
> evidence, that human hearing operates differently when listening to
> reproduced music than it does at all other times, and that generations
> of scientists have just been deluding themselves.
>
> This is how Creation Science operates. Let's hope the audio field never
> sinks so low.

I repeat, the test has never been directly validated for the purposes
espoused here.

And the vast majority of the scientific work has *NOT* been on music and
certainly virtually none has been dedicated to the worth of abx testing as a
means of open-ended evaluation of audio components.
Anonymous
a b } Memory
June 22, 2005 7:05:31 AM

Archived from groups: rec.audio.high-end (More info?)

Mark DeBellis wrote:
> "Buster Mudd" <mr_furious@mail.com> 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
Anonymous
a b } Memory
June 22, 2005 7:06:23 AM

Archived from groups: rec.audio.high-end (More info?)

Greg Lee wrote:
> Mark DeBellis <mad1@columbia.edu> wrote:
> ...
> > The background to this is that I said I thought SACD sounded better
> > than CD, and Chung suggested that I try a simple blind test, to see if
> > I could reliably identify which was SACD and which was CD (after
> > matching levels; SACD and CD layers of same disc). Indeed I could
> > not, at least on one set of trials. Should the conclusion be that
> > SACD sounds the same as CD? Or is it possible that the test I applied
> > is inadequate in some way? How *could* it be possible that the test
> > is inadequate? My question is basically an attempt to explain how
> > that might be. ...
>
> Another possibility is suggested by an informal experiment on smells
> that I did on myself. I took a selection of spices that were all
> in the same type of bottle, closed my eyes, shuffled the bottles
> around, and opened and sniffed them one by one, trying to identify
> the spice by name. I was sure I could do it but was quite amazed to
> discover that I couldn't do it at all. With my eyes closed, I could
> tell the differences perfectly well, but I just couldn't connect the
> names with the smells.
>
> So I think it's *possible* that in unsighted comparisons, the part
> of the brain that does symbolic analysis and associated judgment
> is not in perfect communication with other parts.

Or maybe it's possible that when you make the test tougher, you don't
do as well?

You're doing an open identification test. That would be the equivalent
of listening to one amp and deciding whether it was a Rotel, Adcom,
Krell, or Hafler. To succeed at such a test, even if it were possible,
would require intense practice. All evidence suggests, however, that it
would not be possible--that even if there were some slight sonic
differences between those amps, which you could tell apart in a
quick-switching comparison, you probably wouldn't be able to remember
what is distinctive about each of them long enough to identify a single
example.

Whereas I'll bet lots of professional chefs, with a fair bit more
training than you, would have no trouble putting the right labels on
your spice rack.

Olfactory analogies, like visual ones, don't work.

bob
Anonymous
a b } Memory
June 22, 2005 7:08:34 AM

Archived from groups: rec.audio.high-end (More info?)

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
June 23, 2005 4:05:09 AM

Archived from groups: rec.audio.high-end (More info?)

Theporkygeorge@aol.com wrote:
>
>
> Now that is interesting given that small barely audible level
> differences can lead one to form a prefernce. How can that be?
>
>
The slightly louder level will give the impression of more detail, because
more small levels rise above the threshold of hearing. Since the change is
small, you cannot detect more significant tones, but just a general feeling
of higher resolution.

>
>
> You are
>> speculating that there exists something that violates this
>> established fact. What is it, and how do you know?
>
>
>
>
>
> How do you explain the fact that small level diferences can lead to
> prefeences if we can't remember them in our comparisons?
>
>
If there is a significant level difference, you could in fact detect more
acoustical events, like the noise when the musicians turn the page of their
partitures. In this case you can remember this additional sound, but it has
to be coined and recognized again in each trial. This would not be direct
comparison, because the recognition doesn't give a vague pointer, but a
destinctive indicator. It also needs to be learned by training and you will
need a focused attention.
So whatever people say about long-term and short-term testing, the opposite
seems to be the case, and in fact has been validated by research.
Long-term evaluation with long pauses between the trials will require an
evaluation that is tied to certain distinctive passages, where or where not
a certain sound/noise can be heard. The fast switching will give you more a
general impression of the music as a whole, without the need to concentrate
on separate noises. It will be more joyful, you listen equally to the
instruments, it is more what happens during a concert.

>
>
> Scott Wheeler

--
ciao Ban
Bordighera, Italy
Anonymous
a b } Memory
June 23, 2005 4:07:40 AM

Archived from groups: rec.audio.high-end (More info?)

If I understand you right, it follows from what you are saying that
there will a perceptible difference between two passages only if there
are short corresponding portions of those passages which, when
juxtaposed, will exhibit a perceptible loudness difference. OK, yes,
that does seem plausible (*).

What I am getting from this then is that the relevant task is not
necessarily "Which one is SACD and which is CD?" but "Are A and B the
same or different?" (This is for me the most important point.)

And for the latter, yes, I can see, intuitively at least, why
quick-switch tests are the most sensitive.

The quick-switch test will catch a difference that exists between the
passages only if the samples include points of divergence; if too few
samples are taken, they might just miss them.

(*) About the principle stated above which, if true, is a fact of
psychology. It seems to be saying more or less that differences are
perceptible in context only if they are perceptible in isolation. OK,
suppose I am looking at a photograph with a continuous gradation from
light to dark. And I can see the difference between that and a patch
of constant tone. Then the principle would say that I can do this only
if I can see the difference between small patches where the sample
taken from the first photograph is more or less constant in tone.

But not too small, because once the areas get very small I can't
reliably compare them any more.

OK now the auditory case. There is a signal that gets louder, and I
can hear the difference between that and a signal of constant loudness.
The principle says that I can do this only if I can hear the
difference in loudness between short corresponding portions.

Seems plausible ... and if the portions get to be too short then would
reliability go down, just as in the visual case?

Does it matter how the short portions are "juxtaposed"? Separated by
silence or one followed continously by the other?

Mark
Anonymous
a b } Memory
June 23, 2005 4:08:13 AM

Archived from groups: rec.audio.high-end (More info?)

Greg Lee said:

>I took a selection of spices that were all
>in the same type of bottle, closed my eyes, shuffled the bottles
>around, and opened and sniffed them one by one, trying to identify
>the spice by name. I was sure I could do it but was quite amazed to
>discover that I couldn't do it at all.

IIRC the limit is 3 scents, after that the nose gets overloaded.
Anonymous
a b } Memory
June 23, 2005 4:09:03 AM

Archived from groups: rec.audio.high-end (More info?)

<nabob33@hotmail.com> wrote in message news:D 9akhr02nn9@news4.newsguy.com...
> Mark DeBellis wrote:
>> "Buster Mudd" <mr_furious@mail.com> 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.


But at the current level of validation, you can't be sure the test allows
you to actually perceive some of the differences that might factor into a
longer-term preference.

>
>> 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.

This assumes all aural differences are a function of loudness in one form or
another. Some of us feel otherwise and would like to see this underlying
premises actually validated with regard to phase differences, or harmonic
structure differences, or impulse response differences, or frequency
coherence throughout a dynamic volume change. In other words, is it volume,
or is it a more complex brain processing within a high-complex of aural
stimulae.
Anonymous
a b } Memory
June 23, 2005 4:09:36 AM

Archived from groups: rec.audio.high-end (More info?)

Mark DeBellis wrote:
> "Buster Mudd" <mr_furious@mail.com> 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?
Anonymous
a b } Memory
June 23, 2005 4:10:22 AM

Archived from groups: rec.audio.high-end (More info?)

On 22 Jun 2005 03:05:31 GMT, nabob33@hotmail.com wrote:

>Mark DeBellis wrote:
>> 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.

>IOW, you did a test, you didn't like the result, so now you're
>demanding that we give you some basis for rejecting the result of the
>test.

I think it makes a difference whether the task is "Was that SACD or
CD" or "Were A and B the same or different?" It makes a difference
whether the task is comparison-and-identification or simple
discrimination. There is a reason to reject the result of the test I
did because it was the wrong kind of test.

Mark
Anonymous
a b } Memory
June 23, 2005 4:11:05 AM

Archived from groups: rec.audio.high-end (More info?)

On 22 Jun 2005 03:05:31 GMT, nabob33@hotmail.com wrote:

>Mark DeBellis wrote:
>>
>> ... 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.
>

Doesn't it follow from what you say that musical form can make no
difference? When I am listening to Theme B, it makes no difference
what the character of Theme A was, what motives made it up, and so on.
If it doesn't follow from what you say, why not?

If this is what psychoacoustics teaches us, I'm moving to Kansas!

Mark
Anonymous
a b } Memory
June 23, 2005 4:12:14 AM

Archived from groups: rec.audio.high-end (More info?)

On 22 Jun 2005 03:06:23 GMT, nabob33@hotmail.com wrote:

>
>... analogies, like visual ones, don't work.

You keep insisting that, but there is a wonderful book, Art and
Illusion by Ernst Gombrich, from which the opposite conclusion may be
drawn. Gombrich writes about the development of "lifelike" art and
the very concept of "lifelike." Though he doesn't focus directly on
music, suggesting analogies only here and there, he discusses general
psychological principles that apply across various arts and makes
numerous comparisons between different domains. A classic, along with
Nelson Goodman's Languages of Art, which I've mentioned already.

Mark
Anonymous
a b } Memory
June 23, 2005 4:16:01 AM

Archived from groups: rec.audio.high-end (More info?)

OK, is this the idea.

We want to prove that two sources provide the same information to the
listener in the context of ordinary use.

We appeal now to the following Principle:

If two sources provide the same information in ordinary use, then in a
test in which small, corresponding portions are compared, the listener
will not be able to discriminate them.

In particular, the type of discrimination task is the following: on any
trial, two short excerpts are played, either both from the same source
(a repetition) or from different sources, and the listener has to say
if they're from the same or different sources, and he passes the test
if he says same or different better than chance.

Two observations. First of all, in a test like this there is plenty of
information coming from either source that may not make it to the
listener, such as the "temporally extended" properties I have
mentioned. (Maybe that's obvious.) The thing is, the Principle says
that that's OK because those properties have a certain dependence
relation on the, as it were, "atomic" properties that get compared in
such a test. The relation is, no difference in information presented
unless there is a difference in atomic properties. In other words,
information "supervenes" on atomic properties. It does so even if it
does not *consist* exclusively in atomic properties (because, when I
hear the Brahmsian style of a recorded performance, that is not any
property of a short snippet). (To put the Principle better,
information supervenes on *discernible* atomic properties.)

Second, what is key here is the nature of the test. If I am being
asked whether to say A and B are the same or different, that is one
thing. But if I am trying to say which source a given sample is coming
from, where these have been labelled in advance (like SACD or CD), that
is a different task. And the results might not be the same.

Moreover, there might be information of the temporally extended sort
that is available to me when I listen to longer excerpts but which are
not directly picked up in any test. This would include quick-switch
testing as well as comparison of longer excerpts. It would not be
directly picked up in quick-switch testing because I wouldn't hear
long-enough excerpts to perceive the temporally extended property; it
would elude comparison of longer excerpts if the information fails to
be kept in memory in a way that permits long-term comparison. That was
my initial worry. That worry is allayed to some extent by the
existence of "same/different" testing (if that testing is sensitive to
things on which said information supervenes), but my point is that if
the question is "Was that SACD or CD?" then the result is not a valid
test. The failure to get a correct answer better than chance does not
prove anything. It makes a big difference what the task is.

Make sense?

Mark
Anonymous
a b } Memory
June 23, 2005 7:30:50 AM

Archived from groups: rec.audio.high-end (More info?)

"Mark DeBellis" <mad1@columbia.edu> wrote in message
news:D 9cump01kc4@news2.newsguy.com...
> On 22 Jun 2005 03:05:31 GMT, nabob33@hotmail.com wrote:
>
>>Mark DeBellis wrote:
>>>
>>> ... 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.
>>
>
> Doesn't it follow from what you say that musical form can make no
> difference? When I am listening to Theme B, it makes no difference
> what the character of Theme A was, what motives made it up, and so on.
> If it doesn't follow from what you say, why not?
>
> If this is what psychoacoustics teaches us, I'm moving to Kansas!
>
> Mark

Better order the moving van....Bob didn't warn me and I hit the student
rush! :-)

Seriously, this is what the proponents of quick-switch, comparative testing
*believe* psychoacoustics teaches us. However, as recent experience in this
newsgroup has shown, when they give us a specific reference, which is rare,
it turns out to have much more complex and nuanced information than is
proposed, some of which supports the more complex issues raised here. Then
we are told we can't possibly understand the concepts in these books unless
we devote a full course of study (and preferably a liftetime) to them. Is
this coming from neuropsychologists or neurophysisists or audiologists?
No, it is coming from folks no more or less "literate" in these areas than
ourselves.

Ain't newsgroups wonderful? :-)
Anonymous
a b } Memory
June 23, 2005 7:32:05 AM

Archived from groups: rec.audio.high-end (More info?)

Mark DeBellis wrote:

> OK now the auditory case. There is a signal that gets louder, and I
> can hear the difference between that and a signal of constant loudness.
> The principle says that I can do this only if I can hear the
> difference in loudness between short corresponding portions.
>
> Seems plausible ... and if the portions get to be too short then would
> reliability go down,

No. There is only one point at which the volume of the two passages is
identical, so unless you are listening at exactly that point, and only
that point, the two are going to sound different to you, no matter how
short the samples are. So unless you're extremely unlucky in your
choice of snippets to compare, you'll have no trouble discerning the
difference. And since any good listening test involving musical
passages allows the subject to control the switch, you'll have no
trouble finding other portions of the passage where the differences are
obvious.

Now, you're going to ask, Okay, but what if I'm only given the short
snippet where the levels are the same? In that case, you will hear no
difference. But if that's all you're given, then you can't extrapolate
from that to the remainder of the signal. A listening test is only
valid for what you're listening to.

> just as in the visual case?
>
> Does it matter how the short portions are "juxtaposed"? Separated by
> silence or one followed continously by the other?

A silence of more than a few seconds (maybe even less) will doom the
test.

bob
Anonymous
a b } Memory
June 23, 2005 7:33:22 AM

Archived from groups: rec.audio.high-end (More info?)

Mark DeBellis wrote:
> OK, is this the idea.
>
> We want to prove that two sources provide the same information to the
> listener in the context of ordinary use.
>
> We appeal now to the following Principle:
>
> If two sources provide the same information in ordinary use, then in a
> test in which small, corresponding portions are compared, the listener
> will not be able to discriminate them.
>
> In particular, the type of discrimination task is the following: on any
> trial, two short excerpts are played, either both from the same source
> (a repetition) or from different sources, and the listener has to say
> if they're from the same or different sources, and he passes the test
> if he says same or different better than chance.
>
> Two observations. First of all, in a test like this there is plenty of
> information coming from either source that may not make it to the
> listener,

No, there isn't. The only information coming to the listener is the
information that's actually coming to the listener. If you're comparing
two short snippets, that's all you're comparing, and you can't
extrapolate from that to anything that isn't part of the test.

Since the subject of this thread is "validity of audio tests," let me
be clear: Listening tests are valid for what you're listening to. They
can't tell you anything about what you're not listening to. So please
give up this sophistry.

bob
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