Can you really hear the sound details over 20kHz?

[Don Hills]

Sorry krabby but I am a scientist, and expect people to support their assertions; otherwise, zombies proliferate.

Of course, but since you claim to be a scientist we likewise expect you to support your assertion. And since yours is the extraordinary claim, you go first.

 

[krabapple]

You obviously did not read what I have posted here.

ONE MORE TIME: The "decades of data" are simple sine waves.

One more time: that's false.

 

[tmtomh]

You obviously did not read what I have posted here.

ONE MORE TIME: The "decades of data" are simple sine waves.

IF you have something on fast transients in mixed musical waveforms. LMK. Until then, that claim is not proven. ASR needs to be clear on what is science and what isn't, but is simply likely or a gap-filler.

I am saying this a scientist.

It's not about whether or not it's "proven." It's first about whether the sine wave vs music vs "fast transients" distinction has any basis for being a real thing. If you have evidence for a hypothesis that these distinctions make any difference in human hearing ability with regard to frequency of the sound, then by all means please supply it. This was my entire point - which I'll repeat ONE MORE TIME - that you are relying on a false equivalence of probability ("music might or might not be like a sine wave which might or might not be like a fast transient when it comes to frequency detection in human hearing"), and then based on that false "it's 50-50 it might be true" BS, you are demanding that others document the probable while failing yourself to provide any documentation for the improbable.

 

[pma]

pure analogue toneburt generator/gate and a CRO/DSO.

... makes no differences. The resulting wave generated is of course checked on a scope screen. Not only, also captured by microphone on acoustical side. In fact, the digitally generated wave is more precise than the analog generator output. The Fs/2 upper limit is a non issue here.
The only thing that matters is the acoustical output. And it does not know how it was generated, if by analog or digital.

 

[bennetng]

Hi,
Yes I was a moderator in HA, but I am no more active.

I remember that when the "udial" test tone was posted on Hydrogenaudio, two members reported a fried tweeter on their system after having tried the test tone !
Since then, I always post a warning.

Udial is a test signal designed so as to make the slightest amount of digital clipping or aliasing obviously audible. It features very quiet tones associated with a full scale signal vobulated around 20 kHz.
It was later remade with stronger tones in order to avoid people turning the volume too loud to hear them while not hearing the ultra-powerful 20 kHz sine.

I also tried udial but no equipment damage, and I also commented about it here:
https://forums.dearhoney.idv.tw/viewtopic.php?t=52943&start=18
I suppose Google translate is good enough so I don't need to translate it myself, as my English is also broken anyway LOL.
Now everyone, especially @restorer-john , should read the instruction and inspect the signal clearly:
https://forum.cockos.com/showthread.php?t=201868

I suppose the original udial file looked like this. I don't have the file anymore, only a screenshot:

You can see that it is nowhere similar to udial, it has a fade in , and two out of the three tones are in the non-disputable audible range. When combined with my instructions, I don't see how someone can unconsciously damage their equipment by playing it, because the lower two tones will be painful enough to force people turn down the volume.

Therefore my conclusion is that people only read someone else's spectrogram (in log scale) without knowing the whole story, and accused me, I don't think it is entirely fair.

Agreed. This sort of messing around with HF (and inaudible to many people), high level tones is just plain stupid IMO.

Anyone can put high level, high frequency multitones on a file and call it a 'hearing test' or similar, and destroy a whole bunch of expensive tweeters for no good reason, or cause amplifiers to oscillate.

On the other hand in HA I commented about malformed floating point file may cause equipment damage. Why? Because I played those files unconsciously, and used IEMs with relatively fragile cable. I was scared that I quickly pulled them out from my ears, forcibly. The pulling action damaged the cable.

 

[Blumlein 88]

Any of you do something like the following. Take a high quality high rez recording done with excellent gear. Dump the file in an editor. Brickwall out everything below 20 khz. Slow the speed by 600%. This puts the 20-40 khz octave down in the most sensitive range of our own hearing roughly 3-6.5 khz. Amplify it, you often can get away with 40 db of gain here. Listen to it. There just isn't much there. This is supposed to be an eargasm of an improvement over redbook? Please don't embarrass yourselves.

 

[pma]

https://phys.org/news/2013-02-human-fourier-uncertainty-principle.html

I think the thread is about hearing abilities rather than musical content. The link above reports on interesting abilities in timing detection. Please let‘s not forget that human hearing is not only about spectrum analyzer like function.

arxiv.org/pdf/1208.4611.pdf

 

[Pio2001]

Hi, here are the lowpassed and highpassed versions of pma's test tones. You can download and listen to them.

In the version lowpassed at 10 kHz, although the test signals have disappeared, I can still hear all clicks.

In the version highpassed at 19 kHz, I can't hear anything.

The spectrogram of the original is this :

I highpassed the file using this filter :



The resulting spectrum is this one :

Here is the lowpass filter :



And here is the spectrum of the lowpassed file:

 

[Geert]

My takeaway would be that these studies demonstrate that redbook audio is skating very close to thresholds at which noise or other artefacts may become (marginally) audible in specific listening conditions, although they do not quite establish that properly-processed redbook crosses these thresholds with music as the program.

My main takeaway from the meta-analysis is that degraded hearing (<15kHz) improves the capability to hear ultra high frequencies :

Explains why all these old-timers on subjective forums can hear things science can't explain.

Or could it be that the older testers were better in identifying artifacts resulting from a poor testing methodology (as already described by you)?

 

[andreasmaaan]

Sorry krabby but I am a scientist, and expect people to support their assertions; otherwise, zombies proliferate.

Please explain if I misinterpreted the exchange somehow, but it seems to me that when I asked if you had any support for your assertion, you called my enquiry unscientific.

The fly in the ointment is that music consists of complex waveforms. We don't know for sure if the first test always generalizes to music.

Do we have any evidence, or a suggested mechanism by which, it doesn't?

You are inverting the scientific method.

I'm not trying to score points here, I'd just like to understand what you mean when you say, on one hand, that scientists "expect people to support their assertions" and, on the other hand, that asking for evidence or a suggested mechanism for an assertion is an "inversion of the scientific method".

FWIW, I agree that we don't know for sure (and that we never can).

 

[andreasmaaan]

My main takeaway from the meta-analysis is that degraded hearing (<15kHz) improves the capability to hear ultra high frequencies :

Explains why all these old-timers on subjective forums can hear things science can't explain.

Or could it be that the older testers were better in identifying artifacts resulting from a poor testing methodology (as already described by you)?

I think the most plausible explanation is that it was not a lack of supersonic content that tended to be audible to experienced listeners, but rather a raised noise floor caused by non-noise shaped dither and/or increased noise/distortion caused by truncation.

This is just speculation on my part, though

 

[paulraphael]

Right. Detecting a difference is not the same thing as declaring a winner. Amir also mentioned in his interview that he required specific training in knowing what to listen for.

In an online test from somewhere (I didn’t note the source such that I remember it now), I could distinguish between lossless and lossy MP3 files ranging from 128 to 320 kbps. With headphones in a good headphone amp, I could identify them reliably enough to be better than guessing. But I had to listen to them over and over again, looking for specific details of rendering. And those differences are undoubtedly greater than comparing redbook and high-res. Nothing of what I heard between the better lossy formats and redbook could attract the sorts of transformational experiences people claim. Without the AB comparison, none of what I was listening for would have been noticeable. I consistently cannot hear a difference in my own files (24/96 FLAC needledrops downsampled to 16/44 redbook). But I suspect some downsampling can show aliasing effects or quantizing artifacts if done poorly.

In photography, I always work in raw because I want to have the headroom to make big adjustments without posterization or other artifacts. In sound, I record in 24/96 for the same reason (and my Benchmark ADC is certainly good for 20 bits). In ancient analog days, I recorded live music on VHS HiFi or onto a Tascam 80-8, even when I knew the distribution would be on cassette. Same principle—one might need to boost a track during mix-down or add an effect. But when mixed down from the masters to digital files to put on CD, I could hear no losses even back when I could hear 17 KHz with no difficulty.

But I can hear it when high-res files and CDs are mastered (I said mastered, not mixed) differently, just as when comparing LPs and CDs. But that comes across as differences in EQ.

For nearly all people, this seems like a vacuous argument. I go with my own ears. So far, I can’t hear the difference in lossless formats when mastered the same way.

Rick “who has done his own AB testing” Denney

Your experiences match mine exactly.

I suspect that when audiophiles compare lossy compression to the originals (or red book to high res) they're listening for obvious markers of quality, like reduced frequency response, reduced dynamics, reduced "detail," blurred spacial cues, etc.. When what really goes on, when anything goes on, is the addition of artifacts. At higher qualities, these artifacts might be below the threshold of hearing, but when they become audible, they sound like their own thing.

It's like lossy compression in photography. At higher quality settings, no one sees any difference, without doing tricks like brightening the deep shadows in photoshop to see what's hiding in there. At lower quality levels, when the changes become visible, you don't see what you might expect (blurred details, reduced dynamics, more noise). You see weird little amoebas swimming around the high-contrast edges. They may be there in the high-quality versions as well, but at a contrast level that no one can see.

A trained listener like Amir know where to look for the audio amoebas. I don't. I've occasionally heard the difference between an original file and a 320kb/s MP3, but I suspect these are ones that I converted using bad software or bad settings. With most of them I fail the ABX tests.

 

[pma]

Hi, here are the lowpassed and highpassed versions of pma's test tones. You can download and listen to them.

In the version lowpassed at 10 kHz, although the test signals have disappeared, I can still hear all clicks.

In the version highpassed at 19 kHz, I can't hear anything.

The spectrogram of the original is this :

Filter definition? Impulse/step response? Pre-ringing?

Unfortunately the "clicks" remaining are mostly about filter impulse response. Below is the result with Chebyshev 15kHz, two runs, as per image, zipped flac attached.

The residual after this LPF filtering is an impulse response + ringing at the cut-off frequency:

We are skating on a thin ice here.

 

[Pio2001]

Are you done editing ?

 

[Nango]

Not hearing it doesn't mean not feeling it (elsewhere).

 

[Geert]

Not hearing it doesn't mean not feeling it (elsewhere).

Where do you feel ultra high frequencies, in a practical application?

 

[Nango]

I dont know, no idea, imagine your skin could feel it and it would translate into whatever kind of perception in combination with the < 20khz waves. I was only saying we should not be focused only on our ears when > 20khz.

 

[Wes]

Of course, but since you claim to be a scientist we likewise expect you to support your assertion. And since yours is the extraordinary claim, you go first.

You are confused. I made no extraordinary claim. Please go back and read the posts.

 

[Wes]

It's not about whether or not it's "proven." It's first about whether the sine wave vs music vs "fast transients" distinction has any basis for being a real thing. If you have evidence for a hypothesis that these distinctions make any difference in human hearing ability with regard to frequency of the sound, then by all means please supply it. This was my entire point - which I'll repeat ONE MORE TIME - that you are relying on a false equivalence of probability ("music might or might not be like a sine wave which might or might not be like a fast transient when it comes to frequency detection in human hearing"), and then based on that false "it's 50-50 it might be true" BS, you are demanding that others document the probable while failing yourself to provide any documentation for the improbable.

Let me explain how science works. The person who makes an assertion bears the burden of producing some data showing that the claim is not false, and is likely to be true. So, if you claim that humans cannot hear above 20 kHz you will conduct hearing tests. That has been done for humans and a variety of other animals, using simple sine waves ("tones"). If you then cite those studies on sine waves to show something else, such as musical waveforms, you may be extending those studies too far. The most likely factors involved would be different frequencies in combination with each other, or fast transients. You can do some hand-waving and invoke masking or a Fourier decomposition, but neither is as compelling as an actual study of the phenomenon at issue. Such gap filling isn't illegal but doesn't establish the assertion very well either. Worse is when people become highly emotional and muddy the waters with invalid arguments or even name-calling.

 

[Geert]

I dont know, no idea, imagine your skin could feel it and it would translate into whatever kind of perception in combination with the < 20khz waves. I was only saying we should not be focused only on our ears when > 20khz.

Ultra high frequency energy is very low. No way the skin nervous system could pick it up, and integrate the info with your auditory perception. You also can't feel the spot of a flashlight pointed at your skin. Not to mention it wouldn't explain the supposed ability to detect ultra high frequencies via headphones.

Some people believe in bone conduction, but according to different studies that also doesn't apply to loudspeakers. (It does apply of course to head phones designed for bone conduction, or other transmitters attached to your skull).