Illusions - what do we really hear

[cooky1257]

How many times have you played a familiar track and noticed something new?
In my case that experience is not uncommon-all without switching to a new mega cable or some magic stone. So our perception,or variability of it confers upon us a rather fuzzy experience in terms of consistency and persistence in memory.
Great I say. Don't be afraid of attempts to measure and understand.
I thought the thread was about understanding/discussing the how and why not just using the lack of understanding to justify every (imagined or otherwise) change as attributed fact that this piece /accesory is responsible for that change.

 

[Werner]

If you are maintaining that a better understanding of our auditory perception will not better inform our testing & therefore our design of the the audio chain.

Of course such a better understanding will inform the design of the audio chain and of the audio experience, and if needed of testing, too.

I don't hold the Luddite view that little progress can be made in digital or analogue electronics, I hope we are moving into a more sophisticated consideration of audio reproduction - one that will be informed by our further learnings about auditory perception

So you really think that a new understanding of auditory perception will have a profound impact on the requirements for things like amplifiers and DACs, with results exceeding these from learnings applied to front-end (recording) and back-end (replay) acoustics?

I also take you are still discussing conventional delivery methods, and not direct neural stimulation or custom headphone setups with head tracking ...

 

[Rodney gold]

I think advances in understanding auditory perception and psychoacoustics will drive stuff like DRC forward rather than "improve" the normal hifi items.

 

[adamdea]

How many times have you played a familiar track and noticed something new?
In my case that experience is not uncommon-all without switching to a new mega cable or some magic stone. So our perception,or variability of it confers upon us a rather fuzzy experience in terms of consistency and persistence in memory.
Great I say. Don't be afraid of attempts to measure and understand.
I thought the thread was about understanding/discussing the how and why not just using the lack of understanding to justify every (imagined or otherwise) change as attributed fact that this piece /accesory is responsible for that change.

Of course- the real point is that we are limited by the conventional means of encoding and reproducing. As Werner as pointed out lots of times, there is no reason to suppose that preserving the existing stereo voltage/time relationship will lead to greater perceptual plausibility/reality/verisimilutude. If you made an adc/dac chain perfect it would not make any difference to the gross limitations of stereo.

On the contrary there is plenty of reason to suppose that futzing around with the signal might make for a better sense of reality by exaggerating the inter aural timing and/or phase differences [which can in principal be encoded by conventional stereo mics] and/or the spectral cues you get due to sound having to go round your head, ears etc [which can't be unless you use a dummy head, but even then it won;t be your head and it won't be that much use.].

You can futz around using tried and tested but vague methods (tube amp) which might help.

Or you can try to target it precisely and attempt to recreate what the sound reaching your ears would have been. Either way the point is that you are manipulating the signal to increase verisimilitude. Nothing else will do.

 

[Ciunas Audio]

If Its an illusion , you cant measure it and its different for everyone.
Worst of all its really only applicable to a few nutcases.. the rest of the population really doesnt care.
Progress is driven by the masses ..

Nope!

Illusions are routinely used in perceptual research to probe the workings of the perception being studied - because they work in the same way for almost everybody. Does the McGurk effect work for almost everybody or does everybody perceive it differently?

In auditory scene analysis a popular test they use is called a bistable illusion where we fluctuate between hearing two separate streams or one galloping stream. It's the visual equivalent of the profile of two faces facing one another - we fluctuate between perceiving the faces or perceiving a vase.

These illusions happen because they trigger certain aspects of our fundamental perceptual mechanism that governs that sense.

In the same way the illusion of audio reproduction works because it appeals to certain fundamental mechanisms in our auditory perception - that's why we can buy into the illusion that there is a somewhat believable reproduction of real instruments & voices in a sound stage.

 

[adamdea]

I think advances in understanding auditory perception and psychoacoustics will drive stuff like DRC forward rather than "improve" the normal hifi items.

You put it much more succinctly than I did.

 

[Rodney gold]

My illusion in my room is not the same as in yours - you can use all your logic to tell me otherwise, but you are wrong.

 

[adamdea]

Was that aimed at me Rodney? I'm not sure I know what you mean.[edit- no it wasn't I think, please ignore]

 

[mattgbell]

Illusions are routinely used in perceptual research to probe the workings of the perception being studied - because they work in the same way for almost everybody. Does the McGurk effect work for almost everybody or does everybody perceive it differently?

It's been well known for years that the McGurk effect is highly variable. The biggest variations are between speakers of different languages. Chinese and Japanese show a considerably weaker McGurk effect than do, say, English and German.

In any case, the analogy between the McGurk effect and cognitive biases in hearing (e.g. expectation bias) is a very weak one.

 

[Rodney gold]

No , not aimed at you at all.. was to Jkeny

 

[Ciunas Audio]

How many times have you played a familiar track and noticed something new?
In my case that experience is not uncommon-all without switching to a new mega cable or some magic stone. So our perception,or variability of it confers upon us a rather fuzzy experience in terms of consistency and persistence in memory.
Great I say. Don't be afraid of attempts to measure and understand.
I thought the thread was about understanding/discussing the how and why not just using the lack of understanding to justify every (imagined or otherwise) change as attributed fact that this piece /accesory is responsible for that change.

Yes, what we focus on when listening, changes our perception of what we hear. This is often then cited as the mistaken rule "everybody hears differently".

So, yes when a change is made to the replay chain, There is a natural tendency that we will listen differently & therefore perceive a difference, simply because we are focussed differently. It's important to be aware of this & go back to pre-change situation to focus on the same aspect to see if there is a genuine change. This can sometimes be difficult to tease out & isolate to a specific A/B type change & often requires patience, motivation & training to be able to achieve. I suspect most people aren't interested in this type of approach & simply judge what they like best without trying to forensically analyse it.

 

[cooky1257]

And very often when do switch back you say "sh1t, it was there all the time.."

 

[Ciunas Audio]

Of course such a better understanding will inform the design of the audio chain and of the audio experience, and if needed of testing, too.

OK, we agree, then!

So you really think that a new understanding of auditory perception will have a profound impact on the requirements for things like amplifiers and DACs, with results exceeding these from learnings applied to front-end (recording) and back-end (replay) acoustics?

Well, you see the use of your adjective "profound" is where the issue lies & this is relativistic. I'm reluctant to predict the impact & it does depend on the audience you are talking about - to the man in the street we are all idiots, futzing over stuff that is of no consequence & very far from profound. Hobbyists tend to represent a range from this viewpoint to the other extreme.

I also take you are still discussing conventional delivery methods, and not direct neural stimulation or custom headphone setups with head tracking ...

I expect that a better understanding of the limitations of the current 2 channel stereo will be recognised & some better mapping of the way forward possible but who knows what way it will progress - commercial considerations always dominant progress.

 

[Ciunas Audio]

My illusion in my room is not the same as in yours - you can use all your logic to tell me otherwise, but you are wrong.

That has no bearing on what I'm saying - the reason that you have any illusion that there is some semblance of a band playing in a soundstage & not just two sources of sounds coming separately from each speaker, is because certain psychoacoustic principles are already incorporated in the audio playback chain.

Each room will interact differently with the reproduced sound but our auditory perception also has some ability to hear through the room effects, within reason.

 

[Ciunas Audio]

It's been well known for years that the McGurk effect is highly variable. The biggest variations are between speakers of different languages. Chinese and Japanese show a considerably weaker McGurk effect than do, say, English and German.

Right & this shows that auditory processing is about best guess formulation based on our experience & learning from the real world that we are immersed in & experience on a daily basis. So speech is a particular instance of this - the physical formation of the mouth/tongue when speaking will be determined by the language we have learned & this McGurk conflict between mouth formation & sound only strongly applies to those who have this particular language model in their auditory processing.

It doesn't contradict the deeper understanding that sounds which are in nature will be modelled the same for everyone with a normal brain.

In any case, the analogy between the McGurk effect and cognitive biases in hearing (e.g. expectation bias) is a very weak one.

Yes, I agree - it is a special case of speech recognition which may actually have a different auditory processing pathway to other sounds?

 

[Ciunas Audio]

And very often when do switch back you say "sh1t, it was there all the time.."

Yep, but sometimes there is still a difference heard & we still cannot shake that off. The problem is in trying to isolate it.

As I said, many do not bother to go to the trouble of all of this - they accept that there is a perceived difference & don't really care what's behind it as long as it remains.

 

[Werner]

Well, you see the use of your adjective "profound" is where the issue lies & this is relativistic.

Not at all. I wrote 'profound impact on the requirements of amplifiers and DACs'. Tweaking a few parameters a bit is not profound. Changing them 100% is profound, as is throwing out a handful of traditional performance parameters and letting in a few totally fresh ones.

 

[Ciunas Audio]

No , not aimed at you at all.. was to Jkeny

You might be correct that DRC will benefit most but my feeling is there will also be some interesting advances in other areas of audio too.

 

[Ciunas Audio]

Not at all. I wrote 'profound impact on the requirements of amplifiers and DACs'. Tweaking a few parameters a bit is not profound. Changing them 100% is profound, as is throwing out a handful of traditional performance parameters and letting in a few totally fresh ones.

I'm looking at the phrase "profound impact" from the auditory perception perspective & you seem to be looking at it from the electronic engineering perspective. These are two fundamentally different viewpoints but I would say this - the goal of the whole audio chain is to present as realistic an illusion as possible which is a judgement made by our auditory perception. the concept of what is the driving force is often lost in these discussions, I feel & the electronics become the primary focus.

Yes, I'm sure further knowledge of the workings of auditory processing will have an evolutionary effect on the electronics rather than a revolutionary one. What might have a profound impact to our auditory perception of realism could be a small change to our view of & implementation of the electronics?

 

[mattgbell]

Right & this shows that auditory processing is about best guess formulation based on our experience & learning from the real world that we are immersed in & experience on a daily basis. So speech is a particular instance of this - the physical formation of the mouth/tongue when speaking will be determined by the language we have learned & this McGurk conflict between mouth formation & sound only strongly applies to those who have this particular language model in their auditory processing.

I think what you mean is this: the different levels of 'McGurkness' between languages have to do with (a) the method with which the mouth produces the sound of a given language, i.e. the way language X is formed by any speaker of it, and (b) the way the interface between visual cognition and auditory cognition happens in the listener/watcher, or more precisely the relative positions of visual and auditory processing within the hierarchy of cognition.

It doesn't contradict the deeper understanding that sounds which are in nature will be modelled the same for everyone with a normal brain.

Yes, the same sound envelope will be processed in the same way.

Yes, I agree - it is a special case of speech recognition which may actually have a different auditory processing pathway to other sounds?

Yes, the McGurk effect isn't generalisable outside of language use. There's no equivalent effect for, say, watching and listening to a pianist play.