New phono stage from SOTA

@rauliruegas 

Raul, I am not arguing that other tissues besides ears can sense sound. There is a video of a fellow who is deaf as a door knob who listens to his system daily. He says he can "feel" the music. My only point of contention is at what frequency this occurs at. Most of us can easily sense bass below 250 Hz. But, our sensitivity would decline as frequency rises. People who have lost their hearing would be much more sensitive because when one sense is lost the others are heightened. As far as how high is concerned I do not know. The papers you reference are nowhere near substantial enough. We are not radio receivers or bats. 200 kHz even at insane volumes is highly unlikely. Our nervous systems are not fast enough to register that and our structures are too large to resonate at those that frequency. Electrical signals travel down neurons at 350 feet per second. That is a snails pace. The only way our brains can function the way they do is the distances are small and the number of transistors (synapses) is insanely high.

I am aware of rumours that we may be dreadfully susceptible to subsonic vibrations, but have not yet heard of military research into ultrasonic warfare (and I assume that the military would be the ones to wish to exploit this if it were possible).

@mijostyn Bernard Katz would be proud of you for pointing that out (he was a clever man but a wretched lecturer as I recall). It is surely correct that our neurons cannot support frequency modulated information that oscillates too fast for transmission along the average length neuron. And we haven't allowed for the refractory period whilst the neuron "re-adjusts its dress" or returns the sodium and potassium ions to their resting position. But if I ignore this, I run into a problem. A transmission speed of 350fps means 1Hz is the limit for a 350 foot long neuron, no?  Probably, the longest neurons in auditory circuits are those in the VIIIth nerve itself. Let's say a generous 2" from cochlear to nucleus at the medullopontine junction. So, 350 x 6 = 2100Hz. But we can, when young, hear much higher frequencies. A moment's thought tells me it doesn't work that way at all. Only certain hair cells in the spiral of the cochlea respond to corresponding frequencies of sound. Likely they all send their notifications of having been stimulated along their connecting neurons at the same frequency. IF the cochlear was capable of sensing ultrasonic vibration, then that would be sent upstream at the same speed of 350fps. But we don't seem to hear those very high frequencies, even in the youngest and healthiest of specimens.

One could postulate that a general ultrahigh frequency effect might be exerted on the brain by other means (bone conduction, CSF conduction and ?glial physical vibration), but that wouldn't be anything other, I think, than a general degradation of brain function. I think that assuming we can in some way enjoy music that includes ultrasonic information, even as we have lost the intermediate high frequencies through aging, is hopeful, at best.

@mijostyn  : You are trying to win and this is not the issue.

I never post  or talk about 200khz, so what's all about.

Re-read and then post again or leave that way but please don't try to win, it's not the main subject:

""" Given the existence of musical-instrument energy above 20 kilohertz, it is natural to ask whether the energy matters to human perception or music recording. The common view is that energy above 20 kHz does not matter, but AES preprint 3207 by Oohashi et al. claims that reproduced sound above 26 kHz "induces activation of alpha-EEG (electroencephalogram) rhythms that persist in the absence of high frequency stimulation, and can affect perception of sound quality." [4] Oohashi and his colleagues recorded gamelan to a bandwidth of 60 kHz, and played back the recording to listeners through a speaker system with an extra tweeter for the range above 26 kHz.   """

R.

@mijostyn  : What we can sense and what we need to know how measure, where measure, tools, etc. etc is extremely complex in a human being body where the brain knowledge by scientist/neurologist is only 27% and this 27% not inclusive in " deep " fashion . Your ears maybe can detect 18khz however you listen a way higher frequencies and even the brain sinthetized following harmonics by its incencious memory experiences during your life.

So not you or me or any one else could say: this is inaudible. Well you listen 24khz that is inaudible conciensous for you.

https://www.britannica.com/science/human-sensory-reception

https://www.britannica.com/science/human-sensory-reception/Nerve-function

We all have to learn, I'm learning from this thread about because I have to make some searh on that issue.

Who win? everybody, not me or you but everybody.

R.

Dear @dogberry  :  " is hopeful, at best ".

Well in the link posted  ( the first one. ) those gentlemans came from CalTech, MIT and AES, so are not ametaurs but gentlemans with high knowledge levels and try to explain as better they can:

" From the fact that changes in subjects' EEGs "persist in the absence of high frequency stimulation," Oohashi and his colleagues infer that in audio comparisons, a substantial silent period is required between successive samples to avoid the second evaluation's being corrupted by "hangover" of reaction to the first. The preprint gives photos of EEG results for only three of sixteen subjects. I hope that more will be published ".

At the end is that exist lower than we can think knowledge levels by scientist of the overall human being TRUE " operation " whole body and specially this high frequency main subject because who cares about when it's enough that " somebody " says: " inaudible " and that's it. Rigth?

R.