Understanding Sample Rate

[Spacehound]

4 minutes ago, sandyk said:

 

 Bone conduction is one of the reported mechanisms for noticing HF above the normal hearing range.

I know that.  The reports at still wrong.

[sandyk]

Just now, Samuel T Cogley said:

 

Honest question: Can you say with any certainty that "bone conduction" contributes (or not) to your musical listening?

I have no way of knowing.

I do however know that there are specialised hearing aids designed around bone conduction.

[semente]

Here's one of Mario's (PlayClassics) drums tracks for comparison:

 

 

No doubts which sounds more natural/realistic.

[Ralf11]

8 hours ago, mansr said:

You can also ask the question, what is the minimum sample rate required to capture all the sound there is? The answer is roughly 500 kHz. Recordings done at 352.8 kHz are now readily available. If you examine one, you will see that they have precisely zero signal content above 100 kHz or so and very, very little above 50 kHz. This means that a sample rate of ~200 kHz is enough to capture all sound in actual music, whether we are cats or humans.

 

This is only true if we prevent dolphins from making their own musical instruments -- something the ADMIC* has blocked so far.

 

Bottlenose dolphins can hear simple tones with a frequency up to 160 kHz so we most likely need to keep them from singing too.

 

 

* anti-dolphin musical instrument coalition

[Ralf11]

6 hours ago, psjug said:

That is why the redbook sampling rate is 44kHz (22Khz Nyquist), so that the filter cutoff can be above the audible band.  Philips and Sony really did think about these things.

Edit: maybe this will help https://en.wikipedia.org/wiki/44,100_Hz

 

Wow!  A Wiki on a frequency!

 

Now where is that Wiki on the infinte frequency??

[jabbr]

6 hours ago, beerandmusic said:

 

infinite number of frequencies and infinite number of time slices.

 

Here is what should be an understandable explanation about why there aren’t an infinite number of distinct frequencies between say 1kHz and 2kHz:

 

When 2 equal amplitude waves are supposed (added together) the resultant wave frequency is the mean of the 2 and the amplitude varies with a frequency which is the difference between the two.

 

There are many examples on the web which explain and graph this — take a look. 

 

As two waves of slightly different frequencies are added and as the frequencies move closer together, the amplitude variation lessens to the point where it cannot be resolved within the signal SNR. It is not possible of improve the SNR without limit, At this point the two frequencies are indistinguishable. This is the uncertainty principle applied to frequency. The limit of SNR is the uncertainty principle applied to amplitude — essentially the Heisenberg Uncertainty Principle. 

 

In s digital system, the bit depth forms and be bound on the SNR aside from the physical bound in the SNR. This is why a discrete Fourier transform works with a finite number of bins.

[Ralf11]

48 minutes ago, mansr said:

How do you know it's musical if you can't hear it?

 

You ask the Walrus.

 

Or the Dolphin if your Walrus is overly bandwidth limited.  They are still great with subsonics tho - ya can't beat those vibrissae!

[Spacehound]

17 minutes ago, sandyk said:

 but I have no way of knowing.

I do however know that there are specialised hearing aids designed around bone conduction.

Presumably used by people who are deaf at 57KHz?

I will buy one. Please post me  a currently inaudible but  sufficiently musical  file.

 

[Ralf11]

Just now, Spacehound said:

Presumably used by people who are deaf at 57KHz?

 

I will buy one.

 

 

 

used by jet pilots

[Samuel T Cogley]

15 minutes ago, sandyk said:

I have no way of knowing.

I do however know that there are specialised hearing aids designed around bone conduction.

 

Thanks.  I was just curious if you were claiming to have ultrasonic hearing. 

[mansr]

21 minutes ago, sandyk said:

 Bone conduction is one of the reported mechanisms for noticing HF above the normal hearing range.

Bone conduction doesn't work for airborne sounds.

[Spacehound]

5 minutes ago, Ralf11 said:

 

used by jet pilots

Listen to a lot of high-pitched music do they?

[Spacehound]

4 minutes ago, mansr said:

Bone conduction doesn't work for airborne sounds.

That won't  stop him.

 

Do you like my signature? It's  a recent personal  award from  Stereophile.

[kumakuma]

Bone conduction headsets are used in tactical environments:

 

http://www.safariland.com/special-ops-systems-offline/tabc-iii-tactical-bone-conduction-headset-TABC3_0.html&start=1#sm.000d6tp64yzad4t118q29e4uzoage

 

[fas42]

5 hours ago, adamdea said:

I'm not convinced that you could ever perfectly achieve the reproduction part of the ambisonic soundfield , so I suspect you would still need a theory of what really matters. I also suspect that perceptual science would still have something to say about the limitations even of a "perfect" reproduction though. Because you aren't in the recorded acoustic space  it's difficult to "learn" it.

Similarly with the hrtf it is psychoacoustics that tells us of the need to have head tracking isn't it? And in the absence of perfect hrtf measurements (possibly matching the clothes I am wearing today) you need a theory of what really matters.

 

 

I find it quite amusing that so many need a terribly, terribly technical reason for what is needed to get high quality sound - part of the male game to be able to hold up the Big Breakthrough over one's head in triumph, I guess.

 

What really matters is sufficient quality in the replay chain - because the inner workings of the ear/brain, and  a lifetime of learning to interpret the meaning of subtleties in the sound then does the rest. Using various multi-channel gimmicks, and fancy room setups all can help the mind grok what is intended to be heard - but it's talking the hard road; far better ROI is to fix the audible flaws; and it also means that the whole century plus of recordings history we have becomes fully accessible.

[Spacehound]

4 minutes ago, kumakuma said:

Bone conduction headsets are used in tactical environments:

 

http://www.safariland.com/special-ops-systems-offline/tabc-iii-tactical-bone-conduction-headset-TABC3_0.html&start=1#sm.000d6tp64yzad4t118q29e4uzoage

 

Not at 57K they aren't

[Ralf11]

2 minutes ago, Spacehound said:

Not at 57K they aren't

 

Well, the Navy uses dolphins in tactical environments, so maybe...

[kumakuma]

4 minutes ago, Spacehound said:

Not at 57K they aren't

 

Maybe someone needs to create an updated version of the old JS&A Bone Fone.

 

[Spacehound]

Just now, Ralf11 said:

 

Well, the Navy uses dolphins in tactical environments, so maybe...

They don't need them, they can hear  57K easy.

 

Are they US citizens? Can't have any North Korean ones. Mexican ones are even worse..

[Spacehound]

8 minutes ago, kumakuma said:

 

Maybe someone needs to create an updated version of the old JS&A Bone Fone.

 

That won't work, the bone's got to be real close to your ears, as illustrated:

 

 

[firedog]

1 hour ago, sandyk said:

 

Not quite , at least in the case of some of Barry Diament's recordings with genuine musical content to 57kHZ

 

Maybe, but its also known that 4X rates cover what’s found in the vast majority of recordings, that don’t have either extremely low  or high frequencies - they don’t make it past the microphone. 

The other question is one we don’t talk about much, and that is if 4X and above rates cause more distortions and non linearities in the reproduction chain than the positive qualities they might add. 

[marce]

1 hour ago, Samuel T Cogley said:

 

Honest question: Can you say with any certainty that "bone conduction" contributes (or not) to your musical listening?

I believe yes. My youngest are twins born premature, very. I spent 16 years of speech therapy with my son because he is neurologically deaf between about 3 and 8Khz, how they confirmed this was by doing bone conduction tests (I believe it bypasses the ear canal). But like all hearing its just another way the pressure waves are transmitted to the ear, the same rules of hearing still apply, 20-20. It's the same reason your voice sounds alien when played back from a recording and how you can have totally silent headphone (bonephones).

[Samuel T Cogley]

1 minute ago, marce said:

I believe yes. My youngest are twins born premature, very. I spent 16 years of speech therapy with my son because he is neurologically deaf between about 3 and 8Khz, how they confirmed this was by doing bone conduction tests (I believe it bypasses the ear canal). But like all hearing its just another way the pressure waves are transmitted to the ear, the same rules of hearing still apply, 20-20. It's the same reason your voice sounds alien when played back from a recording and how you can have totally silent headphone (bonephones).

 

I appreciate your insight.  I was more interested in testimony of audio bone conduction as part of the audiophile experience, not so much for proof that audio bone conduction exists.

[firedog]

1 hour ago, sandyk said:

 

There are many reports that the absence of the higher frequencies are noticed, even though we can't hear them directly with our ears.

There are not many reports about airborne sound. And we are talking about airborne reproduction. 

And the Ooashi study that is always mentioned hasn’t been confirmed by subsequent studies. In addition, even Ooashi admitted that his subjects could have been reacting to distortions the extremely high frequencies caused in the playback, and not to the high frequencies themselves. 

[marce]

I don't think so with speaker based sound reproduction unless it's LOUD, bone transducers vibrate in close proximity, it's like a voice or sound in your head, modulated tinnitus.