audiofools...maybe not so much

[ampdoctor]

Ok, now that I've got your attention, the past few days I've been doing some investigations into psychoacousics and stumbled across something interesting.  What I found was something called ASMR and it seems to be some serious lizard brain stuff. To quote wikipedia...

Autonomous sensory meridian response (ASMR) is a neologism for a perceptual phenomenon characterized as a distinct, pleasurable tingling sensation in the head, scalp, back, or peripheral regions of the body in response to visual, auditory, olfactory, and/or cognitive stimuli. The nature and classification of the ASMR phenomenon is controversial. Tom Stafford, a professor at the University of Sheffield, says, "It might well be a real thing, but it's inherently difficult to research."

A large part of this phenomenon seems to involve people experiencing a sense of relaxation as a result of hearing different "trigger sounds". Usually these include soft whispering, clicking noises, crinkling paper, hands rubbing across cloth, etc. The commonality among these things are that they're all sounds with very high frequency harmonic components.

What I'm going to posit is that many audiophiles may be hyper-sensitive to sounds at the limits of human hearing in the higher frequency ranges.  If there's even the slightest amount of ringing on the supply rails or very high order harmonic or IMD products, is it possible that they may be picking up on this and creating a sense of relaxation or agitation depending on the specifics of the content? So when these paleolithic emotions get triggered it's possible that they could be making a subconscious qualitative instead of quantitative decision about the goodness (relaxation), or badness (tension) of the sounds they're hearing.

What I would like to hear are some thoughts, observations or comments on this subject with as little audiophile bashing as possible because there may be something going on here that we may be missing. In particular, I'm hoping for an interesting discussion of psycoacousics, and the percieved limits of human sensory experience.

[hamster_nz]

I am convinced that 99% of it is psychological due to expectations.

My test subject is me. I've been debugging a project - Stereo Line In -> 24bit ADC -> FPGA -> Stereo 24bit DAC.

I had four settings
1) Out <= In
2) Out <= Low_Pass_FIR_Filter(In);
3) Out <= High_Pass_FIR_Filter(In)
4) Out <= Low_Pass_FIR_Filter(In) + High_Pass_FIR_Filter(In)

I was convinced that there was a bug in my code - I could hear a subtle difference between setting 1 & setting 4.

I've spent along time tracking down the bug, but eventually had to admit that I was only hearing the difference because I expected it to have a bug. The math and simulation left no doubt - the two sample streams were identical.

As soon as I convinced myself that the output was bit-for-bit identical, they then started to sound the same!

So, much like differences in the tastes of wines. People expect a wine to taste a certain way, so they do. However I am sure that when given a glass of wine without knowing the accepted description for it even an experienced taster will fail badly to identify it. They haven't "tuned in" to the taste of wine, but have been given the expectation of the experience.

However given the THD figures for the last device in the chain I can't see why people worry about 0.02% vs 0.01% in an Amp - but  if anybody wants two pay for an FIR based all digital crossover, with zero phase shift, with S/PDIF in to 2xS/PDIF out, allowing you to bi-amp your speakers, control the crossover frequency and slope and completely remove the crossover, then come see me.

[AndyC_772]

I went to a hi-fi show some years ago, and a couple of things stood out:

- the range of styles of music being demonstrated was extremely limited, and

- the vast majority of visitors were middle-aged and older men; the demographic which tends to have the worst hearing, especially at the top end of the frequency range.

On that basis I can well believe that a certain group of people derive pleasure from hearing certain sounds, and that those sounds might indeed be quite specific. But that's OK, everyone is entitled to enjoy listening to their own choice of music. I certainly do.

That said, most audiophoolery - by definition - has nothing to do with techniques which could actually influence the sound coming from the speakers, at any part of the frequency range. It's all about technical terms being misused (intentionally or otherwise) to mislead potential customers into believing that a certain product might make their equipment sound better.

[ampdoctor]

Oh, I'm absolutely certain there is no shortage of psychological expectations of a perceived change. I had a client one time who without question could hear a difference in the sound of an amplifier due to the position of a switch. Even when I told him it wasn't connected to anything and just there to fill the hole he STILL heard the difference. Crazy huh?!

I'd say this observation is valid for 99% of the population. The ones that get me curious are the 1% who actually can hear the difference between capacitor types or in my personal experience the difference between brands of transducer coils. Out of curiosity i ran a blind test on this guy and EVERY SINGLE TIME he got it right. The guy was a freak of nature! People like that are the ones that tell me there may be something more going on than meets the eye.

We have to remember that when we look at things like the Fletcher-Munson curves these are based on actuarial data. More recently Robinson and Dadson repeated the experiments and came up with somewhat different results. There's no question that there are some people that exist on the statistical tails of those results.  There's also a fair amount of experimentation that's been done in the field of listener fatigue which suggest that there's a noticeable psychological effect in people when distortion products are introduced to otherwise "clean" program material.

[AndyC_772]

I don't find it at all difficult to believe that swapping one coil for another could actually change the response of the transducer, though. Not by much, perhaps, if they're both produced with close tolerances to the exact same design, but it's not implausible that the frequency response and distortion could be affected.

Compare and contrast with green marker pen / rocks / gold plated mains plugs etc.

[ampdoctor]

There's clearly no shortage of audio"phools" floating around who truly believe that if you dance around the room at midnight and wave a chicken foot over you stereo and put a granite pebble 20 degrees off axis on the northwest side of your power amplifier you'll have amazing sounding audio. Those people are completely delusional. Like I said though, the one's that interest me are those that appear to have a testable and almost extra-senory perception of audio.

As an interesting aside; people do not see the world in 3-D. We actually see in 2-D and our brains make the necessary adjustments accordingly. Something similar can be said for audio. We don't hear in stereo! We actually hear in mono. And again our brains compensate due to the loudness perceived in the left vs the right ear, phase shifts, etc, to give us a different sense of our surroundings.

And yes, these were two brand spanking new reverb tanks for a Fender guitar amplifier. Same specs, same manufacturer. Identical in every conceivable way. What got me going with him was that he came in with a new tank that he didn't like the sound of. Said it was wrong somehow and wanted me to scrounge up a NOS tank.  I was like come on you've got to be kidding me?! So I did an informal test with two accutronics tanks and every single time... BINGO, he knew it! By conventional wisdom it should have been insignificant, especially with a reverb tank that's used as nothing more than a mechanical delay line. Since then I've never dismissed anything off hand.

Animals can detect earthquakes days before they happen, birds can follow magnetic field lines during migration, seals can select their pups out of the cries of hundreds at the same time. In the animal kingdom we've observed outrageously bizarre things, yet when somebody says they can hear the difference between capacitors, near identical pcb layouts, or some other thing, we blow it off and say mehh, it's just psychological. Maybe not!

[con-f-use]

So you are basing your wild theory on a yet unproven, controversial hypothesis in the credible field of psychoacousics. Interesting, tell me more!

Tom Stafford, a professor at the University of Sheffield, says, "It might well be a real thing, but it's inherently difficult to research."

That's normally code for "I think it's bullshit but its not worth my time to prove it to you". I've seen our dean of medicine saying essentially the same thing about homeopathy. I've said the same thing to people asking about astrology. It makes them go away.

Even if he didn't mean it that way, even he was convinced there is a real effect, there's this: Recently the editor of Nature said, that in hindsight 50% of their articles turn out to be false. And that's probably the most renown journal in science. Science is a work in progress and has to be done carefully and tested repeatedly. Even if a professor says something and is convinced of it, it doesn't mean too much. Theories, even proven ones, have to be tested again and again in as many ways as possible. Laymen are convinced far too easily by a scientific publication.

A large part of this phenomenon seems to involve people experiencing a sense of relaxation as a result of hearing different "trigger sounds". Usually these include soft whispering, clicking noises, crinkling paper, hands rubbing across cloth, etc. The commonality among these things are that they're all sounds with very high frequency harmonic components.

When I read words like "seems", "experiencing a sense" and "usually" in a paper, I usually stop paying attention. People should refrain from hypothesizing and look to conduct independent, statistically significant, double blinded studies every time such a question comes up. In fact there are such studies on audio encoding/compression and audio filtering. They could identify certain post-processing that makes audio sound "better" to the human ear. However even comparably cheap equipment and a high grade of compression didn't make any difference to the perceived quality.

[T3sl4co1l]

Complex stimulus triggering a complex memory, highly subject and stimulus dependent.  No academic merit.

Special versus general case statistics.  If you're building an amplifier to sell millions, you work to the average person, damned what any particular result happens to be.  Average hearing response, average impressions, average everything.  That maximizes the number of people to whom it gives value (generally not "value to the average person"), and therefore maximizes the quantity that can be sold.  Good business.

Special case.  A given person might experience things differently: different frequency response, different musical genres, etc.  Optimizing to this will NOT maximize value to the average person (let alone the average consumer), but will maximize the value to that particular person alone (and anyone who has similar stats, but that's likely to be a very small fraction out of the total market).

Double blind tests.  As long as 1. the change is visible to the subject and/or 2. the change is known by the person administering the test (particularly obvious if they are one in the same person!), the results ARE NOT VALID BY ANY SCIENTIFIC OR STATISTICAL MEASURE!  For some reason. . . . . . double blind tests are especially frowned upon by the audiophile community.  Strange, wouldn't you think?  Surely those most especially interested in optimal sound (whether general or specific, as per the preceding paragraphs) would be the most excited about actually having provably ideal results!  Alas, this is not the case!  So one can only therefore conclude..... experience is not just audio alone, but visual, perceptive and more.

There is a monstrously large market for consumer equipment -- millions of units is small potatoes -- but it demands low cost.  There is a narrow market for special-purpose equipment, ranging from the professional (those who actually objectively desire and require high performance equipment) to the rich (who have money to spare and therefore simply buy the most expensive) to the 'believers' (those on the very margins of the bell curve, who desire perfection suited specifically to their taste, and who are generally willing to pay for it).  On the upside, the population even on the fringes is so large (tens of thousands, easily?) that it's a market all its own (part of the "long tail"), which is statistically why audiophool/phile-ry is so visible, and significant, and insignificant, all at once.

Really what it comes down to is: if a person wants to pay, say, $10,000 for an audio system that is not objectively better than a $100 system, it is their prerogative to do so.  Evidently, the sheer act of 1. spending money and 2. knowing that they paid it (and can brag to others that they paid this*) can yield benefits which the pure "sound" alone cannot account for.

*Which is actually an evolutionary thing.  Many species have evolved physical aspects which directly contradict "survival of the fittest", in terms of sheer performance alone; features which are costly to produce, yet physically useless -- counterproductive even -- to possess.  This is known as the "handicap principle".  Does it make sense to spend $10,000 on an audio system that's (objectively) worth $100?  Yes!  It shows -- not  that you can afford $10,000 worth of equipment, because it's NOT worth that -- but that you can actively waste that money and still come out ahead!  That's the mind***k that... brings the ladies, I guess?!

Tim

[T3sl4co1l]

When I read words like "seems", "experiencing a sense" and "usually" in a paper, I usually stop paying attention. People should refrain from hypothesizing and look to conduct independent, statistically significant, double blinded studies every time such a question comes up. In fact there are such studies on audio encoding/compression and audio filtering. They could identify certain post-processing that makes audio sound "better" to the human ear. However even comparably cheap equipment and a high grade of compression didn't make any difference to the perceived quality.

Pertinent;
http://xkcd.com/882/


Tim

[con-f-use]

That is all fine and good as long as people know it's just a status symbol and there's nothing to it. I have a problem with companies claiming unproven and sometimes even outrageous things to fool people into giving them money. Joe averages hears terms like psychoacustics and high frequency components stimulating the brain stem, and makes money decisions based on untested claims engineered sound sciency. That's just fraud. It gets even worse when someone calls companies on their false advertisement, and they answer with lawsuits (see Monster cables).

Even freaks of nature cannot get around physics. The ear has its limits, imposed by things like scattering and dampening of sound waves at the scull, the inertia of the ossicles, the speed, fuzziness and delay in neural transmission and sheer size of the cochlea. On top of that comes electrical noise, bodily noise (blood, heartbeat, breathing, muscle tremor, joint friction) and inhomogenities in your medium of transfer. Even if one clearly underestimates these hard limits, I sometimes see claims in defiance of these hard limits.

By the way I liked the point of audiophiles being mostly middle aged men who are not sensitive to higher frequencies anymore. One could argue they're not consciously sensitive anymore and there might be an other mechanism of perceiving or residual neural activity. But that would be measurable and is very unlikely.

[Polossatik]

That is all fine and good as long as people know it's just a status symbol and there's nothing to it. 

hum yeah, the sad thing is of course that people who realize this in general don't spend ridiculous $$$ on silly things.

Had a nice chap in my "friend of friends" circle, really good bloke, then he got "serious" about audio (got somehow a big paying job, so after the BMW5 and his GF's boobjob, he needed big woofers for his new house with a big living space...).
I'm a bit "the tech" in the circle so when he asked I made some suggestions / what shop to go for "better" equipment etc.
All fine, he bought some nice kit.

Until suddenly he started to go bananas on "correctly ionised polarised" mains cables and other stupid stuff (he discovered a "hifi forum" ) .
He was very disappointed that i never mentioned all this wonderfull stuff to him.
And if i rejected what "he clearly could hear for himself" (he ordered a ton of expensive crap to play with) as "totally without any scientific/measurement basis" then i could really not be any good at "tech stuff".

[amyk]

I was tested a few years ago and could hear a little beyond 30KHz (it's less of a discernable tone but I can still tell whether it's present or not), but don't care for the audiophile stuff - what matters far more than the quality, is whether I enjoy the music.

[Sigmoid]

We don't hear in stereo! We actually hear in mono. And again our brains compensate due to the loudness perceived in the left vs the right ear, phase shifts, etc, to give us a different sense of our surroundings.

Well we have two ears, so by definition we DO hear in stereo. At least the lucky majority of us.
We definitely do not hear in 5.1 surround though...

In the animal kingdom we've observed outrageously bizarre things, yet when somebody says they can hear the difference between capacitors, near identical pcb layouts, or some other thing, we blow it off and say mehh, it's just psychological. Maybe not!

You brought up musician equipment. That's an entire different beast. An effect pedal does something to the sound that's usually not straightforward to model. It adds a distortion - shifts the phase and modifies the power of harmonics. So yes, hearing the difference between two almost identical effect pedals or distortion amps is a real thing - like tasting the difference between two batches of French cheese.
There's a complex taste (or distortion) there to taste (or hear). And we know the brain is really good at capturing patterns in chaotic / nonlinear input.

Audiophoolery is very, very different from this. The admitted goal of high-end reproduction equipment is to reproduce the original sound, to make it as if you were there. That's a lot simpler than adding that specific, iconic flavor to the output of an electric guitar.
An effect or effect amp is beautifully nonlinear - its value is in its nonlinearity. A hi-fi device is marketed for linearity. There's no human factor in linearity, it can be measured. And usually audiophool stuff does NOT stand up to measurement.
Also, for the human factor, blind listening tests usually tend to debunk audiophool stuff, which shows how large an effect one's preconceptions have. More about this:
http://nwavguy.blogspot.com/2011/05/subjective-vs-objective-debate.html

[Rufus]

What I'm going to posit is that many audiophiles may be hyper-sensitive to sounds at the limits of human hearing in the higher frequency ranges.

If they were 'hyper-sensitve' they would have no problem detecting the presence or absence of such sounds in ABX tests.

When you have some proof that audiophiles can actually rather than just claim to detect a difference then you can start positing on what the difference is and how they detect it.

[con-f-use]

Animals can detect earthquakes days before they happen, birds can follow magnetic field lines during migration, seals can select their pups out of the cries of hundreds at the same time. In the animal kingdom we've observed outrageously bizarre things, yet when somebody says they can hear the difference between capacitors, near identical pcb layouts, or some other thing, we blow it off and say mehh, it's just psychological. Maybe not!

We don't blow it off just like that. First of all, when was the last time, you heard your cat bragging about how well it can detect earthquakes? (I've heard stupid shit from audiophiles about how special their hearing is and how bad everyone else's is. If it's so special, why don't they make awesome music, calibrate equipment or predict earthquakes? They'd be making money instead of spending it.)

The way it goes is that people observe their animals being uneasy right before an earthquake. At this point that could just be coincidence or bias. So the next step is to record statistical data.

What percentage of the time is the animal uneasy with no earthquake immanent? How does it's uneasiness correlate to earthquakes? Would I have a similar prediction rate if I guessed randomly at a rate of uneasiness similar to that of the animal?

Then you investigate the physical reason, in case of cats a higher sensitivity in the sensory organ responsible for balance, that is susceptible to earthquake vibrations combined with highly sensitive vibrissae in their paws. Then you test that explanation by subjecting the animal to small vibrations that precede earthquakes. And the theory is right. Who would have guessed in a predator evolved to land on its feed and move in poor lighting?

- For birds its magnetide inclusions in some of their neurons that act like a crude compass combined with a good memory for landscapes, routes and star constellations.
- For seals its a large variance in the scream pattern combined with good triangulation and audio processing.
- For audiophiles it's magic!

It's not that people blow it off. There have been studies. It's just not reproducible, not significant and has no solid underlying theory. That makes it pseudo-science which is worse than esotericism.

[edavid]

Animals can detect earthquakes days before they happen

False.

http://en.wikipedia.org/wiki/Earthquake_prediction#Animal_behavior

After reviewing the scientific literature the ICEF concluded in 2011 that

    there is no credible scienti?c evidence that animals display behaviors indicative of earthquake-related environmental disturbances that are unobservable by the physical and chemical sensor systems available to earthquake scientists.

[Sigmoid]

I've heard stupid shit from audiophiles about how special their hearing is and how bad everyone else's is. If it's so special, why don't they make awesome music, calibrate equipment or predict earthquakes? They'd be making money instead of spending it.

Lol, yes.

Indeed, if you ask a musician off the street, they'll likely say reproduction equipment and quality has little or nothing to do with music itself. A beautiful piece of music will still be itself if reproduced on a bad AM radio with batteries half dead and the antenna up a llama's ass.

I'd say implying that reproduction quality has something to do with the enjoyment of music is like saying that calligraphy has something to do with the quality of literature. If you can read, you'll be able to recognize a letter 'a', regardless of how it's written or printed. In music, the same thing can be said about chords and intervals.

So if audiophools really have some kind of sixth sense to hear minute distortions, it's actually something deleterious to "music".

("You don't want to buy Penguin Books' print of Ulysses, the serif on their lowercase l's is a far too large, and the curvature of their 's'es is all wrong. Also they use digital bitmap printing, if you want proof, check under a microscope! It just gives off a far too aggressive, dry, digital feel! No real literature enthusiast would stoop so low as to read that crap!")

[linux-works]

most people don't have golden ears, but some actually do.

I was demo'ing some audio gear (including spkrs) at a show and the spkrs were from someone else.  he told me that the red/black posts may not be right.  I connected it and used the spkrs anyway.

one guy came by and said he thought the absolute polarity was wrong.  I don't believe he was there when the spkr owner explained that to me.

could it have been just a coincidence?  maybe.  maybe not!

very few people are good 'test gear'.  I know I'm not.  but a select few really are!

[con-f-use]

No doubt there is variation in hearing. After an ear infection I got the frequency response of my inner ear measured to make sure there was no lasting damage. Turns out I'm six sigma better than the average for lower frequencies and two sigma worse for high frequencies. In retrospect it made sense. I tend to get headaches when around large transformers and can hear when a light bulb is about to burn out. But there's no magic to that.

[AG6QR]

I'm sure there are individuals with unusually acute hearing in the high frequency range.  They might be able to genuinely and reliably hear certain differences that are missed by people with more average hearing. 

But I don't believe even the best hearing individuals have ears that outperform our best oscilloscopes and spectrum analyzers.  If a difference is audible, even if only to the elite top percent of listeners, then it should be visible on properly used reasonably high quality test gear.  I think a really basic old 20MHz analog oscilloscope easily outperforms even an extraordinary listener.

So if a bit of gear makes an observable change to the system's frequency response, even if it's not quite audible to me, I'll grant that some people might appreciate the difference.  But if it merely provides more "openness", or "presence", or "richness", or some other effect that needs to be described by words that are more appropriate for a wine tasting room, excuse me if I remain skeptical.

[linux-works]

I don't trust myself to be test-equipment.  I have emotions and agendas that scopes and meters do not

I agree that things that are audible have to be measurable, too.  maybe we don't have the techniques down entirely, but it does not contradict the concept at all.

and so, I will continue to use consistent test gear to evaluate designs and implementations, but I won't rule out that the odd person (lol) can sometimes hear things that most of us can't.  its very rare, but it does happen.

[ElektroQuark]

Well we have two ears, so by definition we DO hear in stereo. At least the lucky majority of us.
We definitely do not hear in 5.1 surround though...

You are mixing source and target here. 

[Sigmoid]

Well we have two ears, so by definition we DO hear in stereo. At least the lucky majority of us.
We definitely do not hear in 5.1 surround though...

You are mixing source and target here. 

My point is, "stereo" is two recordings whose minute phase differences create a perception of spatiality. We do hear in "stereo", as the very technology has evolved as an effort to fool human ears. Stereo is a rendered "image" of 3d soundspace, similar to what a perspective projection is of 3d visual space.

[jwm]

I was reading one forum recently where someone was seriously and profusely advocating taking everything you own apart and desoldering every 74ACxx chip you find (independent of whether it is in the audio path or not) and replacing it with a 74HCxx for a more analog sound. He claims it worked for him so must be the right thing to do and 74AC chips were clearly some sort of scam of the electronics industry. I have not taken audiofool sites seriously since then, I occasionally find myself reading an electronics thread and not realize it is from one of those sites until the advice starts getting odd several replies in and no one is calling the poster on it but is instead proposing a different nebulous idea and then them all wondering about things like jitter and noise without any real numbers. I just want to grab them and say... look! it's in the datasheet! you don't need to guess about things like jitter and distortion and use cargo cult science! it is fully specified! just look! right there!

[BravoV]

... until the advice starts getting odd several replies in and no one is calling the poster on it but is instead proposing a different nebulous idea and then them all wondering about things like jitter and noise without any real numbers.

Audiophoolery actually sort of social disorder or disease, you will never see a loner, must be a pack of them to start the magic, and its never about audio or electronics related since its just a medium.