I don't want to beat a dead horse but I'm bugged.

@mahgister 

I did not not answer. I simply did not read your post.  Your posts for me, are excessive in number, take too long to make a point, and are filled with information that is extraneous.

Fourier transform cannot explain the hearing process which is non linear...

As our discussion is about audio equipment, not the human ear, it is relevant to keep the discussion at this point to equipment.

Many dac technology are based on this flawed assumptions ...

This statement is not correct. There in an inherent lack of understanding in that statement that I don't even know where to start unpacking. However, I will say two things. The goal of signal recreation is linearity. Testing for non-linearity is the purpose of THD measurement. It is an inherent feature of performing Fourier analysis. Our hearing having non-linear processing elements has nothing to do with analog to digital and digital to analog conversion and Shannon-Nyquist theorems. The two are totally unrelated.

Are you trying to imply that there are some timing limitations in DACs that are not sufficient for audio reproduction? In the articles it talks about 10x the Fourier uncertainty limit. That will still be a very very large number compared to the timing precision that digital audio must have to support the THD numbers I see quoted. I am sure you can research this and prove that to yourself.

The goal of signal recreation is linearity. Testing for non-linearity is the purpose of THD measurement. It is an inherent feature of performing Fourier analysis. Our hearing having non-linear processing elements has nothing to do with analog to digital and digital to analog conversion and Shannon-Nyquist theorems. The two are totally unrelated.

You miss my point....I dont contest the value of this Shannon theorem... 😁😊 

The goal in circuit design is linearity for sure... It is electronical design goal...Noise has a meaning here which is not the same than for the hearing process itself...

You dont seems conscious that all electrical measures has an interpretative meaning ONLY in a theoretical framework refering to our actual understanding about hearing...

Some use the concept "accurate" and "noise" in a confused way...They conflated the two possible meanings of the word "accurate" for a non linear detection system like the ears or for a linear tool detection system and they confused the two ways the ratio signals/noise can work for a linear detection system and for a non linear detection system...

The method by which scientist can study the way introduction of noise can help non linear detection system is called: stochastic resonance method...

The way the cochlea is non linearly structured make it able to use an Hopf bifurcation tool analysis inherent in the small fibers cells of the internal ears...

The ears are not a PASSIVE detector system but an ACTIVE non linear one able to amplify ...Then his ability to resolve information exceed many hundredth of times any passive system...

It is the reason why electrical partial set of measures ALONE cannot determine out of listening experiments what will be the sound quality of gear...Like some few deluded ASR disciples falsely claim...

The two groups are deluded not only audiophiles... Sorry....But one at least know that learning how to listen and hearing are FUNDAMENTAL....

deludedaudiophile "You can't compare the frequency response of a headphone to speakers."

You most certainly can and in fact should make such comparisons and they are valid, meaningful, and useful in determining and establishing the relative accuracy of not only each other but the recording itself which is why you will find in many recording studios and other recording environments that both speakers and headphones are used for judgment and evaluation of the work underway.

I suggest you familiarize yourself with these common practices so as to avoid your misinformation.

@mahgister

"The ears are not a PASSIVE detector system but an ACTIVE non linear one able to amplify"

So far so good, just like the human eye is not a passive organ of perception. It is understood that the brain contributes as much to the interpretation of the images detected as the eye itself.

There is no reason to not assume that the ear/brain operates in a similar fashion.

"...Then his ability to resolve information exceed many hundredth of times any passive system..."

Now this is contentious.

For example, does this include the Klippel software and measuring systems as used by some of the most advanced audio labs today?

If not, then the following assumption cannot possibly hold any water, can it?

"It is the reason why electrical partial set of measures ALONE cannot determine out of listening experiments what will be the sound quality of gear...Like some few deluded ASR disciples falsely claim..."

I’m all in favour of upholding the sovereignty of the human mind and perceptual system, but isn’t this just wishful thinking as we enter the age of AI?

"...Then his ability to resolve information exceed many hundredth of times any passive system..."

 

Now this is contentious.

«The technical specifications of the human ear are remarkable. We can hear sounds that evoke mechanical vibrations of magnitudes comparable to those produced by thermal noise (de Vries 1948; Sivian and White 1933). Hearing is so sharply tuned to specific frequencies that trained musicians can distinguish tones differing in frequency by only 0.1% (Spiegel and Watson 1984). Finally, our ears can process sounds over a range of amplitudes encompassing six orders of magnitude, which corresponds to a trillionfold range in stimulus power (Knudsen 1923).

These striking characteristics of our hearing emerge because the ear is not a passive sensory receptor, but possesses an active process that augments audition in three ways (reviewed in Hudspeth 2008; Manley 2000, 2001). First, amplification renders hearing several hundred times as sensitive as would be expected for a passive system. The active process next exhibits tuning that sharpens our frequency discrimination. Finally, a compressive nonlinearity ensures that inputs spanning an enormous range of sound-pressure levels are systematically encoded by a modest range of mechanical vibrations and in turn of receptor potentials and nerve-fiber firing rates. The active process additionally exhibits the striking epiphenomenon of spontaneous otoacoustic emission, the production of sound by an ear in the absence of external stimulation. Although considerable attention has been devoted to these properties in mammalian and especially human hearing, the four defining features of the active process are equally characteristic of nonmammalian tetrapods (reviewed in Manley 2001).»

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2944685/