http://www.soc.surrey.ac.uk/ias/reports/spatialaudio.html
This might be intersting to some people. I take issue with some of the methods and findings, but overall it shows a positive change in the direction of evaluation. At least to a point. At least they were using real music in the studies as well. On the other hand, if you look at the papers written by all of these guys, do you once see them compare the method the music was recorded in to the reproduced spacial perceptions.
http://www.elsevier.com/wps/find/bookdescription.cws_home/675639/description#description
This is a link to the text book I have for the course I took on this subject. It's what I still refrence quite often when trying to understand some aspect of human perception with regard to sound.
I have one more article I can't link because I accessed it through my college access, I'm going to try downloading it to my computer an duploading it as an attached file. Its a PDF so it should work. In the mean time, the article discusses brain activity durring hearing. It talks about how they recently discovered brain activity in humans when they experience ultrasonic frequencies, suggesting we do percieve them, we just don't turn that into actual sound perception. They also found it important in humans localization of sounds. It's been sited in a lot of patents for DSP devices, and I have no idea the legitimacy of the claims, but the study itself seems relativly sound. I mean, all they really found was that by adding ultrasonic material to a tone, humans can more accuratly locate it, but how that applies to real world listening is very debatable.
This might be intersting to some people. I take issue with some of the methods and findings, but overall it shows a positive change in the direction of evaluation. At least to a point. At least they were using real music in the studies as well. On the other hand, if you look at the papers written by all of these guys, do you once see them compare the method the music was recorded in to the reproduced spacial perceptions.
http://www.elsevier.com/wps/find/bookdescription.cws_home/675639/description#description
This is a link to the text book I have for the course I took on this subject. It's what I still refrence quite often when trying to understand some aspect of human perception with regard to sound.
I have one more article I can't link because I accessed it through my college access, I'm going to try downloading it to my computer an duploading it as an attached file. Its a PDF so it should work. In the mean time, the article discusses brain activity durring hearing. It talks about how they recently discovered brain activity in humans when they experience ultrasonic frequencies, suggesting we do percieve them, we just don't turn that into actual sound perception. They also found it important in humans localization of sounds. It's been sited in a lot of patents for DSP devices, and I have no idea the legitimacy of the claims, but the study itself seems relativly sound. I mean, all they really found was that by adding ultrasonic material to a tone, humans can more accuratly locate it, but how that applies to real world listening is very debatable.
Why is it that in a forced-choice duo-trio comparison of wine soak solutions (which I just finished), I was able to distinguish wine stoppered with red corks from the same wine stoppered with blue corks? Trust me, the wines were similar- four other sensory panel members couldn't distinguish them.
Why is it that in ABX testing, sensitive subjects were reliably able to distinguish 0.1dB level shifts or (in John's favorite example) detect fabulously small timing differences?
Why is it that in my haptics testing, users were able to distinguish joysticks that were imbalanced less than 10% from left to right?
In fact, humans are terrific at distinguishing sensory differences when done quickly, on a side-by-side basis (even if the sensing is done serially as is the case with organoleptic and haptic research) and without relying on memory. You provided very pertinent examples of that yourself from vision.
When we rely on sense-memory, that's when our abilities to distinguish one thing from another are badly hobbled. And when we decided a priori what the test outcomes ought to be, then rationalize post hoc, we're throwing away the most powerful tool we have.
Well first, I disagree that these scenereo's aren't relying on memory, the fact that its in succession, even quick succession, suggests that at least the short term memory must be in use. Also, it's of course true that in a way, everything is being placed into memory for at least a period of time, even in real time perceptions.
Now, as to why those are true, my belief is that is because they are so limited in scope its not as hard for our brains to manage. In general when looking at when to and when not to use ABX tests, one of the things to look for is how much information the respondent is being asked to recall. That is one contributor I believe.
The next contributor is that we are more sensitive to certain things than others. For instance, anything having to do with localization is something that our brains are very good at dealing with, and thus we are more sensitive to them. When I was reading the article on hypersonic localization, that was brought up as something our hearing is particularly sensitive too.
However I believe every example you gave remains an example of the pure science high internal validity typical studies, and again, lack exterenal validity. They have little impact on real world listening situations, and really only build a theoretical base by which we can build the broader real life base of music reproduction.
You say the brain is very good at recognizing differences in quick succession, and yet that is contrary the color issue brought up earlier. It's contrary to a lot of taste tests as well that I recall reading, inwhich certain tastes so overwelmed the senses that the tongue became unable to detect differences created by lesser tastes. Then going with the Ultrasonic hearing issue. We can't hear and recongize ultrasonic sounds, we know this, its been studied. Yet, we are now finding that human's can be affected by ultrasonic sound, and from what I gather, its believed that its a tactile issue. However, its clearly, in our brain, connected to our ability to recognize sound and understand words. Yet using old less sensitive methods like ABX to test this will result in nothing, as they are unable to detect any effects from ultrasonic sound. Hence why we were unaware of this before. Now through brain imagry, and later research involving ultrasonic sent straight through the bones in the skull have shown that clearly something is going on, just what isn't as clear.
Also I happen to disagree about your claims on serial recall. Just a quick search on Google, Google Scholar, and my Cornell Library online journals showed numerous articles suggesting limitations in our serial recall, and much of it talking about the need for some sort of assocation for serial recall to be accurate.
As for the cork tasting, I think its because you have experienced and well trained taste buds. That or dumb luck, not sure how that would hold up across the board, so maybe it was lucky guessing. Giving you benefit of the doupt, I'm going with trained taste buds. That touches upon something I think is needed for ABX testing to be accurate, training of the senses for the things being looked for. It is well accepted that training the respondents on what to look for in the situation massivly increases the sensitivity of the measure. Some might try and argue it gives fasle positives, but I disagree here, and its a method thats used all the time. When we use behavioral raters to measure something like Parent Child Interaction, those raters are very well trained on all the domains of PCI we are looking for, the same should happen with ABX testing.
Now, as to why those are true, my belief is that is because they are so limited in scope its not as hard for our brains to manage. In general when looking at when to and when not to use ABX tests, one of the things to look for is how much information the respondent is being asked to recall. That is one contributor I believe.
The next contributor is that we are more sensitive to certain things than others. For instance, anything having to do with localization is something that our brains are very good at dealing with, and thus we are more sensitive to them. When I was reading the article on hypersonic localization, that was brought up as something our hearing is particularly sensitive too.
However I believe every example you gave remains an example of the pure science high internal validity typical studies, and again, lack exterenal validity. They have little impact on real world listening situations, and really only build a theoretical base by which we can build the broader real life base of music reproduction.
You say the brain is very good at recognizing differences in quick succession, and yet that is contrary the color issue brought up earlier. It's contrary to a lot of taste tests as well that I recall reading, inwhich certain tastes so overwelmed the senses that the tongue became unable to detect differences created by lesser tastes. Then going with the Ultrasonic hearing issue. We can't hear and recongize ultrasonic sounds, we know this, its been studied. Yet, we are now finding that human's can be affected by ultrasonic sound, and from what I gather, its believed that its a tactile issue. However, its clearly, in our brain, connected to our ability to recognize sound and understand words. Yet using old less sensitive methods like ABX to test this will result in nothing, as they are unable to detect any effects from ultrasonic sound. Hence why we were unaware of this before. Now through brain imagry, and later research involving ultrasonic sent straight through the bones in the skull have shown that clearly something is going on, just what isn't as clear.
Also I happen to disagree about your claims on serial recall. Just a quick search on Google, Google Scholar, and my Cornell Library online journals showed numerous articles suggesting limitations in our serial recall, and much of it talking about the need for some sort of assocation for serial recall to be accurate.
As for the cork tasting, I think its because you have experienced and well trained taste buds. That or dumb luck, not sure how that would hold up across the board, so maybe it was lucky guessing. Giving you benefit of the doupt, I'm going with trained taste buds. That touches upon something I think is needed for ABX testing to be accurate, training of the senses for the things being looked for. It is well accepted that training the respondents on what to look for in the situation massivly increases the sensitivity of the measure. Some might try and argue it gives fasle positives, but I disagree here, and its a method thats used all the time. When we use behavioral raters to measure something like Parent Child Interaction, those raters are very well trained on all the domains of PCI we are looking for, the same should happen with ABX testing.
But human ones. Nothing at all unusual in my abilities. And, of course, we do cross-correlation and a statistically significant sample set with a 0.05 standard as minimum (0.01 more common) to rule out dumb luck or reduce it to a very negligible chance.
You make my point once again- with trained listeners, Toole, Olive, Lipshitz, Vanderkooy, and the gang have found that very subtle phenomena are detectable as long as the listening tests are serial, i.e., the listeners can switch back and forth rapidly. One can argue that this test is sensitive to these phenomena (e.g., level shift, phase shift, EQ, distortion) and insensitive to others (magic capacitors, jars full of rocks, audiophile hat-racks, fancy power cords); that's a reasonable argument, but to date, no-one has shown that things like copper vs silver wire are ordinarily audible when the listener is only clued by sonics. Alternative experimental methods are discarded or not even considered in favor of BS argumentation ("Blind tests are no good because they fail to show phenomena we know are there," aka the Uri Geller argument).
Really, with the visual stuff, I'd guess that the same thing is going on. I'm not an expert in vision, but I do know that the vision field is very, very small, and when you put two swatches side by side, although it appears that you're looking at them simultaneously, you're not.
After all of this, I guess the obvious question is: Stuart, can you not hear, in your own system, subtle changes in components such as capacitor types, copper or silver wire, different interconnects, different brands of tubes, etc.? And if not, why do you think not? And if not, your experiences don't correspond with mine with my system and even more so with my friends' systems, which are composed of much higher quality components.
My experiences certainly don't correspond with yours as regards to wine-tasting, but that doesn't make your experiences invalid.
John
My experiences certainly don't correspond with yours as regards to wine-tasting, but that doesn't make your experiences invalid.
John
Well, with the wine thing, it's not just a bald claim, it's actually done double blind. So whether or not there's a difference to you, I can prove that there will be a difference to someone. Absent that, it would be perfectly reasonable to be skeptical of the claim that there's something different (besides appearance) between the corks.
I don't do controlled audio testing any more.
I don't do controlled audio testing any more.
The wine thing probably was just dumb luck. Distinguishing differences in what are seemingly insignificant or ridiculous changes to an audio system is related more to familiarity or recognition than to sterile analysis. I haven't seen a test run where audiophiles, in the context of their own personally developed systems, are subjected to double-blind comparisons. No scientist is interested in the results of such a test because he couldn't come to a general, valid (to his way of thinking) conclusion.
Audiophilia, like wine-tasting, is a pseudoscience, and I don't write that pejoratively, and should always be treated as such. Trying to treat it scientifically for one purpose or another is a waste of time.
John
Audiophilia, like wine-tasting, is a pseudoscience, and I don't write that pejoratively, and should always be treated as such. Trying to treat it scientifically for one purpose or another is a waste of time.
John
Actually, I'd be VERY interested if someone did controlled testing in their own system and demonstrated the audibility of, say, green ink on CDs or any of that other goofy-seeming stuff. Very interested indeed. And I suspect I'm not the only scientist who would find that so.
Why would you say that? Double blind, multiple trials, 0.05 significance. And the sort of thing I do routinely in my line of work.
Why would you say that? Double blind, multiple trials, 0.05 significance. And the sort of thing I do routinely in my line of work.
SY said:
Fully willing to admit the possibility my search-fu is terminally weak, I've bever been able to find any rigorous academic tests by those fellows on magic hat rocks or the like. Those I've heard or read about elsewhere, typically IEEE affairs, were almost offensive in their lack of proper method and controls. (The ABX team's traveling dog-and-pony show as recorded in the Boston Audio Society's pages is another good example of bad.) Plenty of valuable info from the big guns on more familiar measured parameters no question. Some of it, such as Olive's work on audible modification by cabinet resonances, ironically counter to many widely accepted 'Hirschisms' of the past, are pure gold.
That's also an unfair generalization on objectors to ABX-as-practiced. Associating them/us with Uri Geller is the skeptic's Godwin.
Incidentally, it's also not the best support to your argument regarding the proper background for doing these tests. I recall clearly it was magicians who outed him and not scientists. Many of the latter still show visible hook marks from that episode.Off topic aside: I can't find the original reference, the days of packing philosophy books are long gone, but the 3-colour paradox was an epistemological problem. How can we be fooled in this way if we perceive reality directly? Yes, it's an oldie.
Unlikely that you will. The peddlers of these ripoffs certainly won't do it and academics don't spend much time testing perpetual motion machines, either.
Only a few (most notably Russell Targ and Hal Puthoff), and they were laughingstocks then and even more so now. Their spiritual descendants, like Gary Schwartz at Arizona, learned their lesson and won't let anyone even vaguely skeptical anywhere near their labs for fear of the same fate. Which is why Schwartz is soundly ignored by 99.999% of scientists.
SY said:
It was good enough for the peer reviewers in Nature. As well mainline science writers like Arthur C. Clarke. Not quite catching the drift here. Toole, Olive and the rest 'just know' without testing? Equating the effects of a cap on an audio circuit with perpetual motion machines is an invalid analogy and begging the question. PM machines are impossible given the contemporary framework of physics. Scientists have properly tested, or debunked from a theoretical standpoint, untold numbers of them in the past. The field has earned the right to consider it bunk. The researchers we're discussing haven't.
You hit the bull's eye on one point though, these topics are understandably anathema to them. If you spend the time and they are bunk, you've wasted valuable and productive years and lose respect in the field for even trying. If results show otherwise you probably spend years getting them accepted for little benefit. I understand the point of view, I just can't agree they've earned the right to say anything about it on the basis of authority alone.
Lots of interesting stuff here, a few points to drop into the debate:
Firstly, long term/short term memory. It has been known for years that for example, in forensic criminology, it is vital to get witness evidence as soon as possible to avoid contamination. The process of storing experiences in long term memory causes all impressions to be sorted through internal filters and associations, causing distortion of those memories. The models our brains use to relate outside experience to sensory impressions filter everything we remember, and once it's gone, it's gone forever.
Secondly, attention. Everything we do experience is again filtered through our expectations. These can be internal, " I can't hear cable differences" or external " the scientist/teacher told me to listen for the position of a sound around me".
A good example of the former is "weapon fixation". It is normal that a victim of sudden violent crime can describe very accurately the knife they were threatened with, yet be unable to give such basic info as the skin colour of the person who threatened them. Our attention focuses on the most important aspects of our surroundings, and discards everything else. This can cause major medium term effects, such as Stockholm syndrome, where a person's world view becomes very distorted.
The latter is a very common experiment in undergrad Psychology courses, for instance, the gorilla in the basketball game. Students were told to count the number of times each player bounced the ball, and completely missed the guy dressed in a gorilla costume running around the court. It's also the basis of most magic tricks.
How does this relate to audio testing? Think about it...
Firstly, long term/short term memory. It has been known for years that for example, in forensic criminology, it is vital to get witness evidence as soon as possible to avoid contamination. The process of storing experiences in long term memory causes all impressions to be sorted through internal filters and associations, causing distortion of those memories. The models our brains use to relate outside experience to sensory impressions filter everything we remember, and once it's gone, it's gone forever.
Secondly, attention. Everything we do experience is again filtered through our expectations. These can be internal, " I can't hear cable differences" or external " the scientist/teacher told me to listen for the position of a sound around me".
A good example of the former is "weapon fixation". It is normal that a victim of sudden violent crime can describe very accurately the knife they were threatened with, yet be unable to give such basic info as the skin colour of the person who threatened them. Our attention focuses on the most important aspects of our surroundings, and discards everything else. This can cause major medium term effects, such as Stockholm syndrome, where a person's world view becomes very distorted.
The latter is a very common experiment in undergrad Psychology courses, for instance, the gorilla in the basketball game. Students were told to count the number of times each player bounced the ball, and completely missed the guy dressed in a gorilla costume running around the court. It's also the basis of most magic tricks.
How does this relate to audio testing? Think about it...
rdf: You'll recall the story behind the infamous Nature article? The disclaimer in that issue by the editors? And the upshot? That's what dragged Randi in, much to the distress and the downfall of the SRI duo...
No bigger Clarke fan out there than me (The copy of "Profiles of the Future" that I got for my ninth birthday set me down my career path), but let's face it, he loved fringe stuff. When he came to lecture a seminar class I was taking on SETI, he spent much of the discussion talking about the Dogon and Sirius, later discredited. His TV show was a real moneypot for him. People love fringe stuff.
I don't know what any of the serious researchers in the field have said about, e.g., magic rocks in a jar. Probably nothing, from authority or otherwise. But when a phenomenon has no evidence to back it up, doesn't comport with known and established physical law, is sold only by the same folks who sell magic chips and magic hatracks, and involves trivia (let's face it, hifi is not exactly a top priority for research), it's unlikely that anyone is going to give it enough credence to embark on a research program.
Now come up with even a sliver of real evidence that there might be something there and tenure-hungry assistant professors will be all over it.
No bigger Clarke fan out there than me (The copy of "Profiles of the Future" that I got for my ninth birthday set me down my career path), but let's face it, he loved fringe stuff. When he came to lecture a seminar class I was taking on SETI, he spent much of the discussion talking about the Dogon and Sirius, later discredited. His TV show was a real moneypot for him. People love fringe stuff.
I don't know what any of the serious researchers in the field have said about, e.g., magic rocks in a jar. Probably nothing, from authority or otherwise. But when a phenomenon has no evidence to back it up, doesn't comport with known and established physical law, is sold only by the same folks who sell magic chips and magic hatracks, and involves trivia (let's face it, hifi is not exactly a top priority for research), it's unlikely that anyone is going to give it enough credence to embark on a research program.
Now come up with even a sliver of real evidence that there might be something there and tenure-hungry assistant professors will be all over it.
To Pinkmouse:
Another nice one is the experiment where they asked witnesses of an accident afterwards to describe the ambulance that picked up the victims. Was it red or yellow? Did it have the blue or the red flash lights on? Almost everyone 'remembered' some details. Except, at this particular accident (which was faked), there was never an ambulance on the scene.
When those witnesses were confronted with that fact, some became VERY angry, even treatening the investigator because they KNEW what they had seen and it was clearly a RED ambulance!
There are here at least two reinforcing factors: one, that normally an accident is associated with an ambulance, two, that the investigator specifically asked about the ambulance so there apparently had been one on the scene.
I always have to think about this when someone angrily tells me that they KNOW what they have heard!
Jan Didden
Another nice one is the experiment where they asked witnesses of an accident afterwards to describe the ambulance that picked up the victims. Was it red or yellow? Did it have the blue or the red flash lights on? Almost everyone 'remembered' some details. Except, at this particular accident (which was faked), there was never an ambulance on the scene.
When those witnesses were confronted with that fact, some became VERY angry, even treatening the investigator because they KNEW what they had seen and it was clearly a RED ambulance!
There are here at least two reinforcing factors: one, that normally an accident is associated with an ambulance, two, that the investigator specifically asked about the ambulance so there apparently had been one on the scene.
I always have to think about this when someone angrily tells me that they KNOW what they have heard!
Jan Didden
I worked for Advanced Micro Devices in Manila from 1979 to 1988 and we did burn-ins of semicon devices as part of the testing process. What i understood about this process is that infantile moratality parts are discovered and eliminated, not let out of the production doors...
how this process got hijacked into audio, i don't undrerstand...
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