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Topic: Why are our ears so foolish? (Read 38664 times) previous topic - next topic
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Why are our ears so foolish?

Reply #25
You mean pixels per degree/minute/second.

I'm pretty sure it's pixels per inch... I think you're talking about the resolution of a capture device, maybe? I was talking about the pixel density of a digital display like the LCD "retina" display on the iPhone.

Why are our ears so foolish?

Reply #26
You mean pixels per degree/minute/second.

I'm pretty sure it's pixels per inch... I think you're talking about the resolution of a capture device, maybe? I was talking about the pixel density of a digital display like the LCD "retina" display on the iPhone.

I believe Woodinville means that PPI alone is meaningless. 

Is the iPhone 4 a "retina display" from 1"?  (no)

Is my 14" VGA monitor a "retina display" from 1 mile? (yes)



PPI + viewing distance is meaningful when discussing perception, but instead of bringing two units to the discussion table we should just talk about PPD.
Creature of habit.

 

Why are our ears so foolish?

Reply #27
PPI + viewing distance is meaningful when discussing perception, but instead of bringing two units to the discussion table we should just talk about PPD.

You're right, of course, and that's what I was wondering myself in my first post in this thread, regarding Ed's statement that sparked this conversation:

Quote
we have as yet precisely NO electronic display equipment that can out-do the limits of the eyes, so far as I know.


We kinda got sidetracked, so yes, I did mean PPI for that sidetracked discussion, but I agree that distance should be considered for the on-topic discussion.

Why are our ears so foolish?

Reply #28
Reading this post http://www.hydrogenaudio.org/forums/index....st&p=494426 got me thinking.

Why are is our ears-brain connection so easily fooled?  I haven't heard of any ABXing on sight, smell or touch issues. My impression is that most people can see the difference (slight though it is) between 720p and 1080p/i and they don't confuse one fabric for another by feel.


Any sensory evaluation must be done by a DBT. Wine tasting is done blind, video quality is done blind, smell is so difficult to test and different between people it's even worse to test, and touch is done via technologies that are equal to a blind test.

Your assumption that ear-brain is easily foold is right. So is any other sensory modality.

Please go to www.aes.org/sections/pnw/ppt.htm and read the slide deck titled "why you hear what you hear". The same data reducton that occurs in the audio sensoria happens just the same n video, except that even more reduction from input to output occurs. There is an "audio vs. video" talk that will also show you some of the issues.

Please, do not make claims based on the fallacy of incredulity and/or ignorance (i.e. "I haven't heard"). I have indeed heard, read, and executed such tests in both audio and video domains, and participated in dbt wine tastnigs.  Major wine contests are nearly all blind at this point, so this is hardly a unique experience, not that I judge such contests...

Of course, I do auditory perception research for a living, and have papers and professional awards relating to both audio and video, which might help in the "informed" catagory.

If I seem brusk, well, I've seen mistakes like this enough times that I've given up counting.

When i said that i "haven't heard", i meant only that.  What i meant to state was "i have not heard of any tests done on this sort of thing, so my current assumption is thus. Is that correct?" I stated it poorly. I don't have the experience that you all do regarding scientific knowledge and i'm eagerly asking questions like this to gain more of a knowledge base while doing my own educating on the side. I was not making a claim based on what i had not experienced.

Besides i admitted that i was wrong way back in post #7.

I'm finding this all fascinating. Thanks all!

Music lover and recovering high end audiophile

Why are our ears so foolish?

Reply #29
Hey Bearcat - I'll just add magicians as another example of other senses being fooled. Comfortable livings are made off that.

I kind of suspect that your question might have a bit to do with the social phenomenon of "audiophiles" which might be a bit special.
Are there winophools?
Are there websites full of people endlessly worming away from the validity of blind wine testing?

I haven't checked ---- Just curious.

Why are our ears so foolish?

Reply #30
Furthermore the physical limits of the eyes as far as resolution goes in much greater than the ears. 
We can out-do the limits of our ears fairly easily, but we have as yet precisely NO electronic display equipment that can out-do the limits of the eyes, so far as I know.


Apple would have you believe their retina display does


The Retina display is around 320dpi. It's not really out-doing the eyes, but it's close enough. You'd need 1000dpi reproduction to make out the pixels on a 320dpi image, such as print.


Resolution is only one parameter.  There's also contrast, and then there's the eye's 3D ability which no electronic display can provide convincingly.

Ed Seedhouse
VA7SDH

Why are our ears so foolish?

Reply #31
Hey Bearcat - I'll just add magicians as another example of other senses being fooled. Comfortable livings are made off that.

I kind of suspect that your question might have a bit to do with the social phenomenon of "audiophiles" which might be a bit special.
Are there winophools?
Are there websites full of people endlessly worming away from the validity of blind wine testing?

I haven't checked ---- Just curious.

yeah, that's what i'm speaking of. I bet there are places like HA for wine tasters. I know there are for cyclists (against spending $500 on a saddle to shave off a few ounces).

At first i read " I'll just add musicians as another example of other senses being fooled." (No one really knows how much we suck?) 
Music lover and recovering high end audiophile

Why are our ears so foolish?

Reply #32
Hey Bearcat - I'll just add magicians as another example of other senses being fooled. Comfortable livings are made off that.

I kind of suspect that your question might have a bit to do with the social phenomenon of "audiophiles" which might be a bit special.
Are there winophools?

Oh yes.  I won't name names.
Quote
Are there websites full of people endlessly worming away from the validity of blind wine testing?

I haven't checked ---- Just curious.


Not as many.
-----
J. D. (jj) Johnston

Why are our ears so foolish?

Reply #33
I was not making a claim based on what i had not experienced.


My apologies. I'm afraid I've seen lead-in questions like this that went in quite a different direction.

Human perception is "interesting" to say the least. Just the fact you discard 99.999% of what you see and hear, and you can GUIDE what you discard, alone, makes perception, shall we say, tricky.
-----
J. D. (jj) Johnston

Why are our ears so foolish?

Reply #34
You mean pixels per degree/minute/second.

I'm pretty sure it's pixels per inch... I think you're talking about the resolution of a capture device, maybe? I was talking about the pixel density of a digital display like the LCD "retina" display on the iPhone.

I believe Woodinville means that PPI alone is meaningless. 

Is the iPhone 4 a "retina display" from 1"?  (no)

Is my 14" VGA monitor a "retina display" from 1 mile? (yes)



PPI + viewing distance is meaningful when discussing perception, but instead of bringing two units to the discussion table we should just talk about PPD.


Generally one talks about resolution in terms of angle subtended, that way the result is independent of viewing distance.  In that case if the pixels subtend less then 1 arcminute, then they probably cannot be resolved at all.

Why are our ears so foolish?

Reply #35
Reading this post http://www.hydrogenaudio.org/forums/index....st&p=494426 got me thinking.

Why are is our ears-brain connection so easily fooled?


Because they were evolved to keep us alive out in the woods and fields, and not  evolved to ace ABX tests of lossy compressors or sort power amps by their sound quality.

Exactly!

Our brain and perception seems targeted at one aim relevant to this discussion: given "noisy" sensory inputs and limited storage capacity, how do I make the most sense out of the world around me, so as not to be eaten by predators, so as to have offspring, so as to have food myself?

This is far from the scientific inquiries into physics and philosophy etc. Many optical/audiological illusions can be explained on this basis, how do you make the most sense out of a limited set of sensors/knowledge?

I find it puzzling that so many people have belief in shamans, religious leaders, Uri Geller and more despite (to mee) the lack of good evidence. I think that the solution must be that during evolution, those that believed in such things could function better in a tribe, and those sceptics would tend to be excluded from social groups, meaning they had to face the sable-tooth tiger all by themselves. Perhaps we are biologically wired (and Darwinistically selected) to believe whatever "authorities" tell us to be true, no matter how unbelievable it seems?

-k

Why are our ears so foolish?

Reply #36
The Retina display, when viewed at normal distances, has practically indistinguishable pixels. But so did the old display, and so does my CRT monitor at home. Now, why I still have a CRT is another debate entirely, but the point is that, if I were to take a 300dpi image, and print it at 100% scale, using a printer that puts ink on paper at 1200dpi, Each pixel of that image would be 4x4 printer dots. You would have no trouble making out the pixels as clean squares then, even at a semi-close look.

Limitations of printer technology "D/A-conversion". I dont see that it is relevant here?
Quote
A pixel image* reproduced at 100% scale on a 326dpi display looks perfectly non-pixelly, because:
a) the pixels are (probably) lined up, so there's no aliasing or other distortion.

On the contrary, I believe the more "lined up" the pixels are, the more visible aliasing would be. Having randomized pixel sites would be far better for real-life pictures.

Synthetic text may be another story, as the content to some degree is shaped to suit the display.
Quote
b) the pixels of the monitor blur together a little, making each individual pixel hard(er) to distinguish.

LCD displays do very little blurring, and glossy ones even less, I believe. Basically, they can be described as red-green-blue rectangles.
Quote
Point b) is very important, as it's the reason my (effectively) 120dpi main monitor looks normal instead of blocky, and also the reason that visual antialiasing works at all.

While audio adheres to Nyquist quite stictly, it is less adhered to in imagery. A camera should have a spatial (and temporal) windowed sinx/x filter, but it never does. Any resampling in the digital domain should be done using a similar filter (it sometimes is). The display device should have another sinx/x filter (it never does). So aliasing is always present to some degree in digital images (temporally in analog film as well).

-k

Why are our ears so foolish?

Reply #37
The Retina display is around 320dpi. It's not really out-doing the eyes, but it's close enough. You'd need 1000dpi reproduction to make out the pixels on a 320dpi image, such as print.


Resolution is only one parameter.  There's also contrast, and then there's the eye's 3D ability which no electronic display can provide convincingly.


That's entirely true. But as far as bit-depth and resolution goes, we're pretty much set.

I'm not sure you'd even want contrast to match what the eye (plus iris) can take, or whether that's even practical, because it seems it would have the minimum requirements of being used in an entirely dark environment, and be capable of emitting nearly as much light as the sun (relative to distance, of course). Just maxing my monitor's brightness when I'm watching a movie or playing a game provides plenty of intensity in my experience. High-gamut monitors aren't a problem technologically— just add more juice to the backlight*, but real HDR images based on floating point values never gained any traction in part because such images are impossible to record at once and can only be produced for real by 3D rendering software.

3D is being worked on.

*) my monitor has enough brightness to literally become painful to my eyes in this brightly-lit office environment. Enough to be felt, in fact. I keep it down, obviously. It's currently less white than the sheets of paper next to me.

Why are our ears so foolish?

Reply #38
Quote
Quote from:  link=msg=730301 date=0
a printer that puts ink on paper at 1200dpi, Each pixel of that image would be 4x4 printer dots. You would have no trouble making out the pixels as clean squares then, even at a semi-close look.

Limitations of printer technology "D/A-conversion". I dont see that it is relevant here?


Relevance goes to illustrating the superior display resolution of print, allowing one to output (significantly-)lower-resolution images' pixels as crisp squares, even when these image's pixels would blend together nicely on its intended display (a monitor; a Retina display).

Quote from: knutinh link=msg=0 date=
Quote
A pixel image* reproduced at 100% scale on a 326dpi display looks perfectly non-pixelly, because:
a) the pixels are (probably) lined up, so there's no aliasing or other distortion.

On the contrary, I believe the more "lined up" the pixels are, the more visible aliasing would be.


If so, then the aliasing is in the original image, and there's nothing you can do about that. Am I mistaken when you seem to also suggest the inverse? Meaning, that misalignment might improve image quality? That doesn't happen. Misaligned or oddly scaled input causes either more aliasing (which is always worse than the original) or prompts resampling in some form (also worse because blurry).

In other words, if your input is crap, don't count on the output device to correct it in a reasonable way, because it won't.

Quote from: knutinh link=msg=0 date=
Having randomized pixel sites would be far better for real-life pictures.


I'm not sure what you mean.

Are you referring to pre-applying some noise to an original image before reducing bit depth, to retain more quality than without noise?

Randomly displacing pixels can only reduce image quality for current resolutions, and on resolutions beyond our vision it would cause slight blurring.

Quote from: knutinh link=msg=0 date=
Quote
b) the pixels of the monitor blur together a little, making each individual pixel hard(er) to distinguish.


   LCD displays do very little blurring, and glossy ones even less, I believe. Basically, they can be described as red-green-blue rectangles.


They blur together because your eyes have a hard time resolving each pixel of a photograph individually, even at the resolutions of an ordinary LCD.

Quote from: knutinh link=msg=0 date=
Quote
Point b) is very important, as it's the reason my (effectively) 120dpi main monitor looks normal instead of blocky, and also the reason that visual antialiasing works at all.


   While audio adheres to Nyquist quite stictly, it is less adhered to in imagery. A camera should have a spatial (and temporal) windowed sinx/x filter, but it never does. Any resampling in the digital domain should be done using a similar filter (it sometimes is). The display device should have another sinx/x filter (it never does). So aliasing is always present to some degree in digital images (temporally in analog film as well).

I'm not sure why you're bringing up Nyquist in relation to that quote of mine. It's not about reproducing a certain image on a certain display device (like the checkerboard image on Wikipedia's article on antialias), it's about the dot pitch of the display device being small enough to ensure the pixels blend together a little, which is necessary for antialiasing to really work as intended. Decrease the dot pitch even further to the point where the eye can hardly see a single dot, and you won't have to antialias at all— the eye takes care it by itself as it simply can't resolve the details.

Why are our ears so foolish?

Reply #39
Why did we develop such easily fooled hearing devices?  I wonder if it's just humans that are so easily fooled audibly.

Bearcat


If your dog could speak, the first thing he'd tell you is to "ditch those lousy MP3s."  (The only humans currently doing so are Sterophile journos in their editorial rants.)

I think he'd be pissed about 96 and 192 kHz sample rates.

Our senses and cognition deliver to us us a filtered and subjective version of reality. That shouldn't be a surprise to anyone.

As to which sense is potentially the most transparent, a quick glance at the literature indicates that the auditory nerves operate at about 600 Kb (both ears) vs. 1.5 Mb for PCM stereo audio. We're losing only half the available auditory information in our ears. The optic nerves are reported to operate at 17.5 Mb vs. 2.9 Gb for 1080p. By this measure, less than 1% of the visual information available to our eyes reaches our brain.

Why are our ears so foolish?

Reply #40
What are your standards of accuracy for making this claim? In terms of audio, just exactly how "insanely accurate" are our ears in terms of distortion, frequency response, dynamic range, etc.?
Given the underlying technology, the ~120dB dynamic range is pretty amazing.

Even "masking" is only a flaw if you want to be a spectrum analyser. In terms of a useful time/frequency analysis trade-off, the ear does well for the tasks we need it for, and masking doesn't get in the way.

While I wouldn't rate my ears for distortion (lousy) or frequency response (getting slowly worse), the ear/brain combination is still better at auditory scene analysis (e.g. picking out one person talking from a crowd of others) than most computers (though they're catching up). The binaural processing is pretty clever too. Inter-aural time delay detection is quite easily modelled, but the way we process (decode) our own HRTFs into spatial information is quite smart.

Cheers,
David.

Why are our ears so foolish?

Reply #41
Comparing human senses to digital bandwidth is just a little crazy.


Really? Given we can actually estimate the bitrate of the auditory nerve (which is underestimated at 600 kb/s by the way, I think that rather badly ignores the time cues. I'd settle for a couple of megabytes) we'v eshown you can.

Now, can you explain why you make this absolute statement with nothing mroe than untestable fluff for an argument? How about some science?
-----
J. D. (jj) Johnston

Why are our ears so foolish?

Reply #42
They aren't claims, it's common sense.  Go outside without sunglasses and come inside and everything will seem really dark for a few minutes.  What, the ears won't act the same way?



Nope, they won't. Ears, unless you've done them damage, adapt in 50 to 200 milliseconds.

The eye takes 15 minutes to do a full Perkinze shift.

The eye's adaptation is very different in mechanics, and is much, much slower than the ear.

It is a mistake to compare the eye to the ear in anything short of the CNS, the peripheral mechanisms are extremely different in almost every fashion.

go to www.aes.org/sections/pnw/ppt.htm and look at 'audio vs. video' for some information on this issue.
-----
J. D. (jj) Johnston

Why are our ears so foolish?

Reply #43
Yeah, go to a club or concert and afterwards tell me if your hearing is 100% back to normal within 50 to 200 milliseconds.  People need to get real and quit relying on mathematics and science to try to explain reality.

That's not the kind of adjustment we're talking about here. That's more akin to having a picture of the back of your eye taken at an opthamologist's office, where you can see spots for a good 15 minutes or more, not going outside in the sun.

Concert noise is often beyond the threshold of safety (*does a quick google search to back that up to his satisfaction*), so you're not talking about the same tolerances at all.  I wish i had paid attention to that 20 years ago)


Bearcat
Music lover and recovering high end audiophile

Why are our ears so foolish?

Reply #44
They aren't claims, it's common sense.  Go outside without sunglasses and come inside and everything will seem really dark for a few minutes.  What, the ears won't act the same way?



Nope, they won't. Ears, unless you've done them damage, adapt in 50 to 200 milliseconds.


This begs the question how loud does sound have to be in order to do damage, whether temporary or permanent?

According to U.S. Government sources, ear damage can be caused by sounds in excess of a mere 85 dB.

U. S. National Institute Of Health Hearing Loss Article

Whadoya think JJ, is this article for real, does it need some more interpretation, or is is alarmist bunk?

Why are our ears so foolish?

Reply #45
They aren't claims, it's common sense.  Go outside without sunglasses and come inside and everything will seem really dark for a few minutes.  What, the ears won't act the same way?



Nope, they won't. Ears, unless you've done them damage, adapt in 50 to 200 milliseconds.


This begs the question how loud does sound have to be in order to do damage, whether temporary or permanent?

According to U.S. Government sources, ear damage can be caused by sounds in excess of a mere 85 dB.

U. S. National Institute Of Health Hearing Loss Article

Whadoya think JJ, is this article for real, does it need some more interpretation, or is is alarmist bunk?


I think the 85dB level is reasonable. There are some frequency domain issues to address, and 'A weighting' is not one of them.

But 85dB is not unreasonable as a point that causes temporary threshold shift, which is in fact harm, at least of a temporary nature.
-----
J. D. (jj) Johnston

Why are our ears so foolish?

Reply #46
This begs the question how loud does sound have to be in order to do damage, whether temporary or permanent?

According to U.S. Government sources, ear damage can be caused by sounds in excess of a mere 85 dB.

U. S. National Institute Of Health Hearing Loss Article

Whadoya think JJ, is this article for real, does it need some more interpretation, or is is alarmist bunk?

It would only beg the question if you were posing a circular argument, such that your premise included your claim of truth. Classic example: God exists because God wrote the Bible and the Bible tells us he does."  It does *suggest* the question however.  See? We philosophical people can be as anal as you scientist types  (and the misuse of that phrase is a pet-peeve of mine).

That link was the first one i found in my Googling.  I have mild tinnitus that i don't know the cause of (it gets worse and better on some days and is almost completely gone on others) .  I do know that the clattering of plates is louder now than before i had it and slightly painful.  I have read that the ringing is caused by feedback, like from a microphone.  Your brain turns up the volume too loud to compensate and you get feedback.  Of course i read that in a Stereophile years ago so i don't know how accurate it is. If ears are damaged, and then the volume is turned up in certain ranges, do they adapt more slowly and thus are more prone to damage the next time they encounter too high a noise level?
Music lover and recovering high end audiophile

Why are our ears so foolish?

Reply #47
This begs the question how loud does sound have to be in order to do damage, whether temporary or permanent?

According to U.S. Government sources, ear damage can be caused by sounds in excess of a mere 85 dB.

U. S. National Institute Of Health Hearing Loss Article

Whadoya think JJ, is this article for real, does it need some more interpretation, or is is alarmist bunk?

I believe that industry limits of 85dB have been set with the goal that industry workers should be able to work for 40 years, 8 hours a day, in that kind of noise, and still have enough remaining hearing to be able to follow a conversation?

-k

Why are our ears so foolish?

Reply #48
I believe that industry limits of 85dB have been set with the goal that industry workers should be able to work for 40 years, 8 hours a day, in that kind of noise, and still have enough remaining hearing to be able to follow a conversation?
I think it comes from a classic study (repeated by several others) of hearing loss in Jute Weavers. They had several thousand subjects (IIRC) and plotted noise exposure level vs exposure time vs hearing loss - because (usefully) different areas of the factory had different noise levels, and different people had worked there for different lengths of time, and no one had ever protected their hearing.

Results: there's a wide variation between individual subjects (just like some people manage to smoke and not have it kill them), but on average longer exposure causes more hearing loss, and higher levels cause more hearing loss. The graph of these results makes it obvious why the current limits were chosen - you can see the lines flatten out at the chosen limits. IIRC over a working lifetime, 85dB won't make "any" difference. 120dB+ makes a difference very quickly.

One criticism is that the standard audiometric tests used only go out to 8kHz. I suspect that most HA readers would be a bit upset if they only maintained their hearing out to 8kHz, and started losing frequencies above that!

Sorry I can't find the graph to post - I had a paper copy 10 years ago, but...

Cheers,
David.

Why are our ears so foolish?

Reply #49
So now I wonder what the dBage is of my headphones. Is there a simple way to measure the levels of what I normally listen to?