PONO audio format

[FORTRANS]

Hi,

Another example I thought of, the Nyquist criterion depends on exact sine waves, theoretically and practically. Of course music can almost be decomposed into sine waves, but is it exact? The hysteresis present in real air, at real varying temperatures, and all the other non-linearities of stubborn reality, shows the answer is "no, not exactly". To the extent that real music varies from precise sine waves, to that extent Nyquist doesn't apply

   Yeah, that always bugged me.  The Nyquist criterion is always
quoted to justify sampling rates.  And it works for sine or square
waves.  Feed it a cosine wave and it fails 100%.  As real world
sound should have a random phase angle, sampling at the Nyquist
rate should therefor have 50% distortion.  But that is never
discussed or even mentioned.  Annoying.

   Not that I should care in the real world, due to frequency loss,
and tinnitus adding hiss and whistles.  And most audio devices
currently sold not being hifi anyway.  The remote to my radio
died recently, so I went back to where I bought it, they can't
replace the remote, and they no longer sell radios.

Cheers,

Steve N.

[Siekmanski]

A couple of years ago a friend of mine bought a 192kHz sample rate capable sound card and he also said he could hear above 20kHz.
I made a proggy for him that did a mono frequency sine sweep from 20Hz to 96kHz on the left output channel and connected it to the right input channel.
With a FFT of both channels on screen, I proved to him that the sound card produced IMD below 20kHz and convinced him that this was the reason he could here signals above 20kHz
Proof was shown on screen. It turns out we both could hear nothing above 16 kHz ( we both thought we had golden ears hahahaha... )

Here's some stuff to read about human hearing:

D. R. Campbell, University of Paisley: http://media.paisley.ac.uk/~campbell/AASP/Aspects%20of%20Human%20Hearing.PDF

College of Santa Fe Auditory Theory: http://www.feilding.net/sfuad/musi3012-01/html/lectures/007_hearing_II.htm

At the bottom of the page:

You Need to Know
•Human hearing: 20Hz - 20kHz
•Healthy young children may have a full hearing frequency range up to 20,000 Hz,
•by the age of 20, the upper limit may have dropped to 16,000 Hz.
•From the age of 20, it continues to reduce gradually to approximately 8,000 Hz by retirement age.

[rrr314159]

siekmanski,

I think you're being 2 dogmatic about this issue. A few considerations,

all these ref's are simply repeating the same info, in the same words: they all got it from one source. So no point in "multiplying entities unnecessarily" :) It's like i don't buy somebody's argument, so they xerox it and send me 12 copies

I believe them all! Same thing I've heard for many years: "normal healthy child up to 20k, age 20 16k, age 60 8k". I don't doubt it's true for normal people. So - what would be the limit for exceptional people? Consider any other human ability: IQ, visual acuity, height, archery, basketball, swimming, you name it: exceptional is always far above normal. "Normal healthy children" have an IQ up to, what, 120? Exceptional is 200. Normal healthy height, male: 6'2"? Exceptional, over 7'. And so forth.

having thought about it, I'm quite sure a pediatrician told me I heard beyond 20K at age 10 or so; think it was 22K. Today, I tested myself at age 63. I can hear 13K clear as a bell, after that not sure but I think the speaker's at fault not me. It hurts, starting at 11K or so. The pediatrician told us I was exceptional, "20K is the usual limit". But he didn't write a paper on me! He'd seen such before - it wasn't a real big deal. So really exceptional may indeed be as high as 28K.

So - are all these papers u reference (really, just one paper, repeated) lying? No. They're clearly not interested in the q. of exceptional range, they're only mentioning normal range then moving on to the topics they care about - all the rest of audio processing. Note, they don't even mention a variance; it's just not something they're concerned with.

***** Above is not too important

Music is a lot more than just pitch! You're ignoring transients (percussion, note attack), without which music is not music (except maybe Gregorian Chants). Fourier transforms are irrelevant to "clicks". The key question is, how quick a transient can be heard? Like percussion, and note attack: a quick click. At 44.1 u get 22 microseconds, but not reliably. It could "fall thru the cracks", or not be reproduced well. So it probably does a good job with clicks down to, maybe, 100 mics or so. So, how fast a click can a human respond to?

Mechanotransduction by stereocilia is highly sensitive and able to detect perturbations as small as fluid fluctuations of 0.3 nanometers, and can convert this mechanical stimulation into an electrical nerve impulse in about 10 microseconds

- 10 microseconds - corresponding to 100KHz! But this ref has a note, "citation needed". And, does it even apply to this question? Dunno. Can't find any more data on "clicks". But u need to cover this base if you really want to analyze the topic.

One more problem, entire theory of fourier transforming, Nyquist absolutely depends on linear response. With a non-linear receiver it's invalid. Well, human brain is significantly nonlinear. Here's a good paper Auditory abstraction from spectro-temporal features to coding auditory entities from 2012 (already old!).

However, A1 participates in coding more complex and abstract aspects of auditory stimuli without coding well the frequency content, including the presence of a distinct sound or its echos. [9] Like lower regions, this region of the brain has combination-sensitive neurons that have nonlinear responses to stimuli.[5]

- note, "nonlinear". This paper also makes it clear that sounds beneath conscious awareness, in the inferior colliculus and medial geniculate body of the thalamus, affect emotions (like, in music) directly via the amygdala.

Don't misunderstand. I don't trust Niel Young; I don't care how many famous musicians say Pono is great, I don't trust them either; I'll trust my own ears. Or better, wait a couple years and see what people think of it. The type of analysis you're attempting in such uncertain areas as aesthetics and cortices is, let's say, more difficult than u think.

There is a large degree of individual variation in the auditory cortex, as noted by biologist James Beament, who wrote, "The {auditory} cortex is so complex that the most we may ever hope for is to understand it in principle, since the evidence we already have suggests that no two cortices work in precisely the same way."

The complexities of contemporary neuroscience are continually redefined. Thus what is known now of the auditory system has changed in the recent times and thus conceivably in the next two years or so, much of this will change.

The auditory cortex plays an important yet ambiguous role in hearing. When the auditory information passes into the cortex, the specifics of what exactly takes place are unclear.

- Humility in the face of the unknown: highly recommended

[Siekmanski]

You are right about repeating the same info. ( I feel a bit ashamed about this, let me carried away a bit too much )
Certainly there are exceptional people that have exceptional hearing skills, I don't argue with that.
It's true, we don't know exactly everything how the brain functions.
At several universities this audio phenomena has been studied, ABX tests (44.1kHz and 192kHz) showed the same results as flipping a coin.
But this will always be a subject of discussion. ( see the Audio Forums )
I still believe that ( and maybe I'm wrong ), PONO is just another marketing stunt to let us buy new speakers, bigger hd's, new amplifiers and we have to re buy our music library again.

[dedndave]

it can be hard to sort out the BS, that's for sure - lol
when digital TV came out, everyone wanted to sell you a new antenna
well, the old antenna is probably ok   

[rrr314159]

I still believe that ( and maybe I'm wrong ), PONO is just another marketing stunt to let us buy new speakers, bigger hd's, new amplifiers and we have to re buy our music library again.

- Agree, I'd put the odds definitely in favor of a marketing stunt, maybe 90 to 10 ... no way I'll buy it for at least a year or two. If it's worthless should be dead by then. Even if turns out to be good, I probably won't get it; rather make my own music than listen to someone else's no matter how well it's reproduced. Just wanted to make my point about, u might say, "unlimited potential" of human beings

[edit] admittedly there's also the "unlimited gullibility" of human beings

[jj2007]

- Humility in the face of the unknown: highly recommended

Absolutely! I've always been fascinated by telepathy, for example. I'm agnostic, as usual, but I wouldn't be surprised at all if it worked 8)

However, common sense is also a fascinating concept

Btw, the guy I quoted above, Roger Russell, was (is?) the Director of Acoustic Research at McIntosh Labs and the originator of the well-known McIntosh loudspeakers, and thus might have had an interest to sell you expensive cables. He refrains from doing so, though.

[rrr314159]

I've always been fascinated by telepathy, for example.

- often u can read someone's asm question and know what he's trying to say better than he (or she) does - particularly when they're a newbie. Almost as if u "read their mind". Does that qualify?