"It is and it is not [surprising]," Magnasco told Phys.org. "We were surprised, yet we expected this to happen. The thing is, mathematically the possibility existed all along. There’s a theorem that asserts uncertainty is only obeyed by linear operators (like the linear operators of quantum mechanics). Now there’s five decades of careful documentation of just how nastily nonlinear the cochlea is, but it is not evident how any of the cochlea’s nonlinearities contributes to enhancing time-frequency acuity. We now know our results imply that some of those nonlinearities have the purpose of sharpening acuity beyond the naïve linear limits.
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New sound models
The results have implications for how we understand the way that the brain processes sound, a question that has interested scientists for a long time. In the early 1970s, scientists found hints that human hearing could violate the uncertainty principle, but the scientific understanding and technical capabilities were not advanced enough to enable a thorough investigation. As a result, most of today’s sound analysis models are based on old theories that may now be revisited in order to capture the precision of human hearing.
"In seminars, I like demonstrating how much information is conveyed in sound by playing the sound from the scene in Casablanca where Ilsa pleads, "Play it once, Sam," Sam feigns ignorance, Ilsa insists," Magnasco said. "You can recognize the text being spoken, but you can also recognize the volume of the utterance, the emotional stance of both speakers, the identity of the speakers including the speaker’s accent (Ingrid’s faint Swedish, though her character is Norwegian, which I am told Norwegians can distinguish; Sam’s AAVE [African American Vernacular English]), the distance to the speaker (Ilsa whispers but she’s closer, Sam loudly feigns ignorance but he’s in the back), the position of the speaker (in your house you know when someone’s calling you from another room, in which room they are!), the orientation of the speaker (looking at you or away from you), an impression of the room (large, small, carpeted).
"The issue is that many fields, both basic and commercial, in sound analysis try to reconstruct only one of these, and for that they may use crude models of early hearing that transmit enough information for their purposes. But the problem is that when your analysis is a pipeline, whatever information is lost on a given stage can never be recovered later. So if you try to do very fancy analysis of, let’s say, vocal inflections of a lyric soprano, you just cannot do it with cruder models."
By ruling out many of the simpler models of auditory processing, the new results may help guide researchers to identify the true mechanism that underlies human auditory hyperacuity. Understanding this mechanism could have wide-ranging applications in areas such as speech recognition; sound analysis and processing; and radar, sonar, and radio astronomy.
"You could use fancier methods in radar or sonar to try to analyze details beyond uncertainty, since you control the pinging waveform; in fact, bats do," Magnasco said.
Building on the current results, the researchers are now investigating how human hearing is more finely tuned toward natural sounds, and also studying the temporal factor in hearing.
"Such increases in performance cannot occur in general without some assumptions," Magnasco said. "For instance, if you’re testing accuracy vs. resolution, you need to assume all signals are well separated. We have indications that the hearing system is highly attuned to the sounds you actually hear in nature, as opposed to abstract time-series; this comes under the rubric of ’ecological theories of perception’ in which you try to understand the space of natural objects being analyzed in an ecologically relevant setting, and has been hugely successful in vision. Many sounds in nature are produced by an abrupt transfer of energy followed by slow, damped decay, and hence have broken time-reversal symmetry. We just tested that subjects do much better in discriminating timing and frequency in the forward version than in the time-reversed version (manuscript submitted). Therefore the nervous system uses specific information on the physics of sound production to extract information from the sensory stream.
"We are also studying with these same methods the notion of simultaneity of sounds. If we’re listening to a flute-piano piece, we will have a distinct perception if the flute ’arrives late’ into a phrase and lags the piano, even though flute and piano produce extended sounds, much longer than the accuracy with which we perceive their alignment. In general, for many sounds we have a clear idea of one single ’time’ associated to the sound, many times, in our minds, having to do with what action we would take to generate the sound ourselves (strike, blow, etc)."
What does it means for audio ?
It means that objectivists pretending that human sound perceived qualities may be only illusions, "good" or pleasant" as subjective qualities being subjective experience are then considered "inexistant impressions... The business to please human ears is for them a fraud... All there is to say about "qualities" is reducible after many blind test ELIMINATED all false pretenses to a mere set of LINEAR measures.... And these linear measures are established as the only standard for creating a good audio design even if any electronic circuits subjected to music bursts into it , instead of sine waves, can produce non predictable audible results...As Van Maanen argue in this article :
https://www.temporalcoherence.nl/cms/images/docs/FourierConditions.pdf
then if Van Maanen is right audio design must be investigated and conducted under the guidance of human ears... It is a craft ... Not a mass producted activity only...
But the crux of the matter is through the discoveries of the fundamental non linear working of the human ears/brain hyperacuity, that this hyperacuity was developed by EVOLUTION history for survival reason related to the urgency to recognise speech and natural sounds, and also music, because music and speech are born TOGETHER...
This means that the "qualities" negated by the objectivists not only exist but are the ONLY OBJECTIVE BASIS for the understanding of human hearings...Then the efforts to reduce audio science to "technological linear measures "of the gear reflect complete ignorance of psycho-acoustic science, instead favorizing the direction of mass standardized design productions instead of qualitative experience andhigher qualitative design, because anyway the highest qualitative audio production CANNOT BE REDUCED to mass market engineering productions , nevermind the level of measures excellence used, they are at the end the results of creative artful CRAFTMANSHIP then they are way costlier ..
All of what is perceived is not measurable... A rainbow exist but need a neurophysiological subject to exist... Qualities being perceived by humans comes from a field of studies in psycho-acoustic and neurology taken very seriously here and which science never negate them a priori as in the technophile objectivist world motivated by mass market regulations of the PRODUCTS and by also regulation of the human being himself...(Transhumanism is here to stay for now )
We will rule say some objectivists what you will hear and what you will not hear because the "qualities" dont exist anyway... Sound is the domain of subjective "illusions" they claim .... Saying so they are FORGETFULL of the way evolution created our BIASED EARS/BRAIN system because it is biased by and for the survival dimension not as a passive tool; our brain is not a passive tool, it is a participant in the creation of sounds with meanings and for yesterday favorizing our survival, and today manifesting also as what we call our "pleasure" , and which are also qualitative IRREDUCIBLE values ... Then contrary to any industrial tools we used which are ultimately linear and time independant, our ears/brain work non linearly in a dependant time domain for our survival and for our pleasure ...
At the end my opinion :
Did Amir information is useful ? Yes it is... Falsyfying gear market specs is useful information...
Did Amir theory about gear design and human hearing is the last word in audio ?
Absolutely not... Audiophiles can go on listening and write their faillible opinions.... Science dont negate human experience but study it.... Why science goes on with this study till today ? It is because TECHNOLOGY is far from understanding human hearing not only hyperacuity but cameleonic power as in echolocalization , the brain, and the qualitative perceived world... Goethe is no less important than Newton...By the way it takes real sound source resonating in the world with their intinsic materials qualities to produce sounds for the ears/brain...
The physics of sound waves is not enough... Why ? Because most sounds we perceive we produce them by speech acts or by musical craft, then sound is not only waves in the air, it is a sound source with a qualitative perceptible inside we PROBE as dolphin or bat probe an object...Then in psycho-acoustic science the perception and emission of sounds are related IN A NON LINEAR WAY , which means that sound qualities cannot be evaluated as is evaluated industrial material audio design...in the same way audio engineering craftmanship is an ART based on psycho-acoustics not reducible as said the designer and physicist Hans van Maanen to the Fourier domain...