It was suggested that a thread on auditory perception & its relation to this hobby or just the topic in general may be of interest to some?
A lot of posts about auditory perception, perceptual testing (blind testing) & other aspects have been posted already but scattered throughout other threads so this might be an area where some of this could be amalgamated or not - depending on how the discussion goes? In a lot of ways discussing perceptual testing in threads where there happens to be an ongoing perceptual test is often the best way to understand the nuances of this area but I can understand people wanting to be left alone to have a bit of fun (even though they mostly take it as a serious endeavor & not just a bit o fun) However bun fights seem to be the outcome on those threads so let's try to avoid this happening here.
One of the last terms I used on another thread was "perceptual narrowing" which seems to be misunderstood - I actually used the wrong "perception narrowing" term in that post & maybe that's where the misunderstanding comes from?
"Perceptual Narrowing" is defined as:
My speculation was that some aspects of autism may be related to this "perceptual narrowing" & its failure to fully take place in the development of infants. At about 6-8 months infants begin to show this change - whereas before this age they can perceive any/all differences in the sounds of any language - after this they can only differentiate between the sounds of the languages they are exposed to. This has wider importance than just speech learning & applies also to environmentally significant sounds.
My premise was that autism may not fully go through this "perceptual narrowing" during their development & are not filtering environmental sounds in the same way as others?
Anyway, another topic that might be of interest to many is the whole research area called Auditory Scene Analysis, ASA for short. This is the study of how we make sense of the vibrations hitting our eardrums & create, internally, auditory objects as part of an auditory scene which is hopefully correlates to the physical world & its objects surrounding us. This is the same as we do with visual perception & they share a lot of similar functionality (& some areas of the brain). Indeed its the same objective for all our senses - to generate an internal model of the physical world as filtered through the particular sense mechanism & associate analysis
There are a number of key points about ASA but it's also useful to explain a bit about visual perception, in order to better understand auditory perception
- as with all our perceptions, this internal model of the world is actually an analysis of the continuous stream of nerve impulses arriving from the sensory organs
- Our eyes don't generate nerve signals that are transformed directly into a moving picture in our brain - the signals are analyzed in various ways (in various streams) & based on this analysis & an understanding of how objects behave in the world, an internal model is created which we call our view of the world.
- The workings of the underlying analysis are often exposed/examined by the use of illusions which expose the brain's analysis & in these cases the mistaken view generated (usually the error is based on the brain's understanding of the normal behavior of object's in the world)
- also the nerve signals arriving moment to moment are often not sufficient for this analysis to create a single version of the image that matches exactly to the signals so there is almost always some ambiguity - in mathematics it's what's called an ill-posed problem - a unique solution (one visual image) doesn't exist based on the data (nerve signals) being received.
- So all our perceptions use other information to try to quickly solve this analysis dilemma in real time (the milliseconds delay between physical event & our perception of it). Some of this information comes from other senses which are then correlated in real time - so we have eyes & ears often working together to solve the ill-posed problem that the data from only one sense would result in. Another source of information is the accumulated understanding built up during development years & later of how the real world objects work - so inferences are made from this knowledge (internal models) of what we are seeing/hearing
- all of this is happening below our level of consciousness
- So the nerve impulses originating from our hearing mechanisms are different to the way engineers look at waveforms i.e frequency, amplitude & timing - there is some correlation but I would suggest that our auditory perception is actually working more at the macro, auditory object level, rather than at the finer frequency, amplitude, timing level which is why we find it more difficult to isolate & identify frequency, amplitude, timing changes in streams of music.
- we are more focused on the patterns within the soundstream although frequency, amplitude & timing are elements in this pattern recognition.
Lots more can be said about this but as a starter this is probably enough to form the basis for discussion?
One other thing to note - the workings of perception (particulary auditory perception) is an active area of research & we certainly don't know all the mechanisms involved
A lot of posts about auditory perception, perceptual testing (blind testing) & other aspects have been posted already but scattered throughout other threads so this might be an area where some of this could be amalgamated or not - depending on how the discussion goes? In a lot of ways discussing perceptual testing in threads where there happens to be an ongoing perceptual test is often the best way to understand the nuances of this area but I can understand people wanting to be left alone to have a bit of fun (even though they mostly take it as a serious endeavor & not just a bit o fun) However bun fights seem to be the outcome on those threads so let's try to avoid this happening here.
One of the last terms I used on another thread was "perceptual narrowing" which seems to be misunderstood - I actually used the wrong "perception narrowing" term in that post & maybe that's where the misunderstanding comes from?
"Perceptual Narrowing" is defined as:
My speculation was that some aspects of autism may be related to this "perceptual narrowing" & its failure to fully take place in the development of infants. At about 6-8 months infants begin to show this change - whereas before this age they can perceive any/all differences in the sounds of any language - after this they can only differentiate between the sounds of the languages they are exposed to. This has wider importance than just speech learning & applies also to environmentally significant sounds.
My premise was that autism may not fully go through this "perceptual narrowing" during their development & are not filtering environmental sounds in the same way as others?
Anyway, another topic that might be of interest to many is the whole research area called Auditory Scene Analysis, ASA for short. This is the study of how we make sense of the vibrations hitting our eardrums & create, internally, auditory objects as part of an auditory scene which is hopefully correlates to the physical world & its objects surrounding us. This is the same as we do with visual perception & they share a lot of similar functionality (& some areas of the brain). Indeed its the same objective for all our senses - to generate an internal model of the physical world as filtered through the particular sense mechanism & associate analysis
There are a number of key points about ASA but it's also useful to explain a bit about visual perception, in order to better understand auditory perception
- as with all our perceptions, this internal model of the world is actually an analysis of the continuous stream of nerve impulses arriving from the sensory organs
- Our eyes don't generate nerve signals that are transformed directly into a moving picture in our brain - the signals are analyzed in various ways (in various streams) & based on this analysis & an understanding of how objects behave in the world, an internal model is created which we call our view of the world.
- The workings of the underlying analysis are often exposed/examined by the use of illusions which expose the brain's analysis & in these cases the mistaken view generated (usually the error is based on the brain's understanding of the normal behavior of object's in the world)
- also the nerve signals arriving moment to moment are often not sufficient for this analysis to create a single version of the image that matches exactly to the signals so there is almost always some ambiguity - in mathematics it's what's called an ill-posed problem - a unique solution (one visual image) doesn't exist based on the data (nerve signals) being received.
- So all our perceptions use other information to try to quickly solve this analysis dilemma in real time (the milliseconds delay between physical event & our perception of it). Some of this information comes from other senses which are then correlated in real time - so we have eyes & ears often working together to solve the ill-posed problem that the data from only one sense would result in. Another source of information is the accumulated understanding built up during development years & later of how the real world objects work - so inferences are made from this knowledge (internal models) of what we are seeing/hearing
- all of this is happening below our level of consciousness
- So the nerve impulses originating from our hearing mechanisms are different to the way engineers look at waveforms i.e frequency, amplitude & timing - there is some correlation but I would suggest that our auditory perception is actually working more at the macro, auditory object level, rather than at the finer frequency, amplitude, timing level which is why we find it more difficult to isolate & identify frequency, amplitude, timing changes in streams of music.
- we are more focused on the patterns within the soundstream although frequency, amplitude & timing are elements in this pattern recognition.
Lots more can be said about this but as a starter this is probably enough to form the basis for discussion?
One other thing to note - the workings of perception (particulary auditory perception) is an active area of research & we certainly don't know all the mechanisms involved
In regards to Autism, I think it is the other way around, that a highly Autistic individual tend to focus on a specific field of interest from an early age, the rest is just noise.
I remember an Autist that had no interest in anything, but he could locate any piece of string, no matter how small or insignificant (to anyone else). He could communicate very well as long as the topic was "string", but nothing else was of interest.
Edit:
Or do you mean that the neurons do not have the same opportunity to form strong connections after a limited amount of instances? If so: then yes, I think this might be the case.
Edit2:
And I resent the assumption: "all of this is happening below our level of consciousness"
That is not a fact, it is something one can be made aware of. Knowing what your faults are to compensate for them is something many people have done.
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this is about perception, which is not what you where talking about in PMA's thread, there you kept going on about the validity of abx because of lack of controls and vehemently extorting that people where drawing false conclusions based on results/findings.
seems your already hedging the row with the suggestion that perceptual narrowing and autism are related, not sure how that applies to ABX testing unless your pre saucing this goose to later say all participants are mildly autistic.
seems your already hedging the row with the suggestion that perceptual narrowing and autism are related, not sure how that applies to ABX testing unless your pre saucing this goose to later say all participants are mildly autistic.
I'm no expert (even though I play one on TV
) but my 4K UHD Samsung TV certainly looks good - great colors, great contrast, great detail & I'm sure that side by side with an analog TV it would be obviously better but there's one thing I notice which I don't remember analog TV doing - whenever there is a large section of black or grey (probably applies to any single color too?) which is color gradient from top to bottom, I see an unnatural banding in this presentation on TV?What I would suggest that we need to bear in mind - these reproductions of images or audio are evaluated by our perception & so some aspects may be perceptually annoying - much more than measurements (if they exist) would lead one to believe. I'm not sure you have experiences what I'm talking about but I wold suggest that it may well be an issue with digital TV? Could it be sorted - I'm sure it can - maybe the manufacturers have decided that it happens so seldom that it is OK (bearable by users) in the TV price range ?
For instance johnego, on another thread, has stated that early fatigue is often how he knows if something is wrong with audio reproduction but it's not something he can spot in quick A/B testing. So, in other words, it's not a problem that immediately jumps out in listening i.e it wouldn't be easily measured, I would suspect. But I would consider a flaw that causes fatigue & interferes with our enjoyment of the music is serious in the grand scheme of the hobby & enjoyment of music.
Yes, what I've just said (in a long winded way) is that measurements don't tell us how something will sound but many say this & then make it into a case that our feelings, etc can't be measured - what I'm saying is that it's not about the emotional response, it's about our auditory perception mechanism finding that the reproduced soundstream of the music is incongruent with its internal analysis/model in some way (yet to be discovered) & as a result it is working harder (causing fatigue) to resolve the ambiguity in the signals it is receiving
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OK but I'm thinking of autistic kids I've experienced who find normal room noise problematic - noise that seems perfectly fine for the rest of us. Maybe I'm wrong - it's was just me surmising
Yes I'm saying that the usual developmental stage where this change in the neuronal net happens is somehow being affected?
Sorry if my words gave you this impression but what I meant was that the above developmental changes we are not conscious of. Similarly non-autists aren't aware that this filter is in place & they can't differentiate between sounds in another language that they were able to do when below 6 months of age.
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Yes & yes I still hold that position although I would apologize if it was perceived as vehemence - I am passionate & when pushed back from many people, explanations given & still many people ignoring what I said but posting their replies to me, anyway - I just find frustration sets in & I get a bit tetchy
Yes the working of perception is very much relevant to perceptual testing which I'm sure you get.
Please, not with the accusations - trying to avoid bun fights
I find many aspects of perception are interesting including perceptual testing (ABX & other).
"perceptual narrowing" in our development is of interest to me - my comments to Kaffimann on the other thread were just my surmising.
Sometimes I also find brainstorming (surmising) of ideas is interesting as long as one is willing to be wrong & I'm willing to be wrong
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I'm no expert (even though I play one on TV
...
Are you talking about color banding from poor compression algorithms or bandwidth restrictions?
This has nothing to do with the monitor itself.
TV standards were set in the 1940s; only modest change was possible to analog TV systems. Digital was a complete re-think after 50 years of fancier chips. The gross metrics are FAR better than NTSC/PAL TV. (Yes, the JPEG-like artifacts as they cram too many subchannels onto one carrier/wire are a new annoyance...)
Audio recordplayers were more tolerant of incremental improvement. Extending from 6KC to 20KHz did not obsolete the old players. Mono to Stereo was done with little trauma. Noise reduction in mastering was snuck-in and generally an improvement. (Consumer Dolby B is more debatable.) When Digital came in we had a good idea what the ear could perceive, but digits were still expensive in the 1980s. CD gave us "just enough" digits; not a bad choice, but left some cream in the jug. There are better (more bits) choices, but bits are still expensive. That leads to Compression, which is again a just-enough compromise, and the residual error is very not-natural. (I was given a jazz sax file, the note-spits sounded like snare drum, and the MP3 encoding may well have been optimized for disco not jazz.)
And of course: anything YOU build sounds best! You can DIY analog audio. Nobody DIYs digital from naked Silicon. Design is limited to selecting the "best" mass-produced DAC and maybe DIYing a PCB.
Could be, as I said I'm no expert?
OK, but I understood the question to mean normal TV viewing of broadcast channels, not BlueRay or games playing? Don;t know about these but wasn't there an issue with digital TVs about fast moving image blurring - has this been solved?
Other can teach me about this area, no doubt.
Asking a question here as requested:
Originally Posted by mmerrill99 here https://www.diyaudio.com/forums/eve...file-tube-amp-record-test-77.html#post5634696
"Remember the attack starts at low amplitude & ramps up depending on the risetime of that particular sound - obviously a cymbal strike has fast risetime in comparison to cello bowing but they all start from quiet background"
What do you mean they start from a quiet background?
Originally Posted by mmerrill99 here https://www.diyaudio.com/forums/eve...file-tube-amp-record-test-77.html#post5634696
"Remember the attack starts at low amplitude & ramps up depending on the risetime of that particular sound - obviously a cymbal strike has fast risetime in comparison to cello bowing but they all start from quiet background"
What do you mean they start from a quiet background?
More and more of those people seem to be coming around to being willing to put up with some digital, don't you think? More people seem to be interested in digital cross-overs and room correction. There are still a few holdouts, and some of them might come around too if they had good enough dacs to drive their otherwise analog systems. Chord Dave is only $10k and some change, and it is reputed to sound very good. So, is the complaint really about digital, or maybe low-cost digital?
Just to explain the background to this question so it's not a confusing post for everyone.
This arose on that linked thread when jonego stated that he perceived some CD players sounded slow.
Max Headroom replied that "Low 1/f noise of the decoder stage oscillator will make the output sound solid and stable...which can be interpreted as sounding 'slow' when compared to more noisy clocking"
cbdb seemed to mix up temp with what was being said & I stated that it was a perception of slowness not that the song actually played slower
So I went on to try to elucidate how I felt Max's statement could result in a perception of slowness in the sound - it was about our perception of sound (what else?
) - the attack stage of each sound we are particularly sensitive to & focus on. This attack portion defines the perception of the start of a each sound. Blurring of our perception of the start of each sound in the soundstream can affect our perception - as Max statesWhat Max is saying is that "low 1/f noise" (close in phase noise or jitter) in the the oscillator in the decoder stage can result in clearly defined perceptual starts of each sound resulting in "solid & stable" (I would expand this to "solid & stable sound stage") Why? Because when the start of each sound is clearly perceived the sound stage is better defined & stable - the soundstage snaps into shape. So how can this be perceived as "slower"? Perception pays significant attention to patterns - patterns are often defined by the regular timing of sounds. Auditory perception uses prediction as one of it's analysis techniques where we anticipate the next occurrence of the same sound. When this timing is clearly perceived (attack stage) we can more easily resolve the signals rather than trying to reconcile blurry timing. With this clarity in patterns & timing, players can appear to have more time, more relaxed playing which actually can be interpreted as slow.
Now to ScottJ's question - I suggested that two possible mechanisms in low close-in phase noise oscillators could result in more accurate timing of the perception of the start (attack) of the sound:
- Low jitter
- lack of dynamically changing noise (low noise modulation)
Noise modulation means the noise is only present when signals are being handled, not when there's no signal present. This means that at the very start of the replay of the attack (when the signal is low amplitude before it has ramped up) if there is modulating noise mixed with the signal it might affect our perception of the start of that attack stage - a blurring of the perceived start of the sound. Perceptually, this is equivalent to the effect of jitter.
Hope this makes sense to ScottJ & other readers?
A very good question to which I will do my best to answer. Analog television was never really that good.
I have been in what was at the time, and way back in the 1980's, Granada TV's 'state of the art' television video recording and controlled lighting studios. You could watch a live feed of a properly calibrated Sony TV camera as seen on a properly calibrated Sony TV monitor, with the sound (equally well recorded) played back on a industry standard Yamaha NS1000 monitor. It was Coronation Street, and looked like a 3D hologram on a 2D screen. Unbelievable, but true.
After that illusory moment of pure televisual Nirvana, it was all the way down hill to the average punter watching the telly on a cheap TV badly tuned, with a poorly calibrated cathode ray tube all shot to pieces - except the sound was rather good, or shall I say 'good enough' to put up with, but without really knowing any better or understanding why. There was no need to. Coronation Street was Coronation Street, and that was all that mattered. Money for old rope.
In the late 1930's it was discovered that if the sound is even halfway good, one can tolerate watching any old televisual rubbish. The TV transmitters were never really powerful enough to transmit a decent signal over long distances without crowding out other analog radio frequencies, and what with weather atmospherics and solar activity, only a relative few who lived near to a transmission station got anything like a decent picture.
A cheap colour TV factory calibrated television would have a life span of around about 12 months before it was a drifted piece of junk. So, it was never ever any good. Except perhaps, for watching old films shot in Technicolor, but that is another conversation altogether.
I don't have a television, I don't watch television, I don't like television, but out of curiosity, I do like looking at other people's consumerist level television's while I'm in their homes. The digital picture quality is certainly very different, but in many ways equally as artefact ridden as the 'bad old analog' it replaced. What a complete and utter con. A shameless, and deceitful manipulation of human sensory perception. Show business, I guess.
Other than that, I cannot comment on high-end 4K Home Theatre. I'm sure it's wonderful, but I really have better things to do with my time and money. Other than watching hundreds of films as DVD's on a laptop, it is now 12 years since I watched a film in a cinema. It was 'No Country For Old Men' shot by Roger Deacon on his first foray into HDR digital motion capture and digitally projected. I thought it looked and sounded fantastic.
ToS
Just a video explaining "Auditory Scene Analysis and Natural Sound Statistics" presents some things I've already mentioned but extends it - sometimes it's good to hear the same things from another or from another viewpoint
Can you say what your problem is?
AN ill-posed problem is one where there is not a unique solution based on the data available - in other words, the nerve signals the brain receives could arise from a number of different scenarios, how does the brain decide which scenario the signals actually represents? If it doesn't get it right we end up in an illusion.
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Yes, he's saying exactly what I just said - many auditory scenes can lead to the same nerve signals arriving at the auditory cortex - auditory processing's job is to quickly analyse the most likely scenario & use this as the preferred internal model of what is being received from the vibrations of the eardrum.It's possible I'm not understanding him clearly (he's gabbling
"there are many sets of possible sounds that add up to the observed mixture"
This may be easier to explain by a simplistic example in speech - have you ever had the situation where you are hearing the spoken words of a sentence & it is making sense until later in the sentence when you hear more words, the meaning is changed. Your first understanding was an example of the model that best matched what you were hearing but the later context made you correct your earlier assumption in the sentence & a new understanding replaces the previous preferred understanding.
The same applies with more generalized non-speech sounds - an internal model of the auditory scene that the nerve signals is generated by our auditory processing machine - this is the best fit auditory scene match to the arriving signals but as more signals arrive, this model can be replaced by a new model which better matches the new collection of accumulated signals & so on & on it goes.
But obviously we are not comfortable continually changing our internal model as the soundstream progresses so every effort is made to supplement the missing data with data/signals from sight, knowledge/learnings of the behavior of sound in the world so that we can reduce this ambiguity. And it is generally, mostly successful but not always.
A standard term, in math or signal processing an ill-conditioned problem has local solutions that are not a global best solution. This can happen in problems like image restoration where false detail and things not really "there" can fool one into accepting them.
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