Can you really hear the sound details over 20kHz?

[sergeauckland]

Maybe IMD?

This is what happens if you play 2 single test tones.
In this case 19 and 20 (both not audible for me) but a spike at -70 as a result might be perfectly audible.

Pretty unlikely. -70 dB below programme levels of, say, 90dB won't be audible at all. It might just, on tones in the absence of other signals or with your head against the 'speakers, but not otherwise.
S

 

[Geert]

How hard can it be to filter a 24/96 or 24/192 recording to 20kHz and AB that against the original ?
Better make sure the transducer has no problems with >20kHz material.

Why bother, as in the latest study with more than 300 participants no one could here a difference https://www.realhd-audio.com/?p=6993.

 

[Vincent Kars]

-70 dB below programme levels of, say, 90dB

Might it be this is about a DAC so -70 dB compared with 0 (dBFS?)
Or is this about playing at 90 dB so this is as 20 dB?

 

[sergeauckland]

Might it be this is about a DAC so -70 dB compared with 0 (dBFS?)
Or is this about playing at 90 dB so this is as 20 dB?

I meant playing at 90dB SPL with the intermodulation products at 70dB below that so at around 20dB SPL .


S

 

[Vincent Kars]

So any DAC producing distortion below -70 dBFS is a good one?

 

[rdenney]

As for me, at age 62, I cannot hear much above about 12 KHz. I have one recording of a 15 KHz tone (on a test LP) that I thought was worn off by some past stylus gouging--I heard absolutely nothing. But I saw a nice, high 15 KHz spike on my RTA, when listening to Advent speakers, which are not exactly known for their strength in the top half of the top octave.

It's one reason I use instruments to set the high range on my system. I want it to sound like real life, not like my memory of sound from back when I could hear the flyback transformers in computer monitors. Not that I really remember what music sounded like in that register then (I do remember what those monitors sounded like). Compensating for age would cause misery for the local canine population.

So, if my system makes a recording of my jangling car keys sound like my jangling car keys, then I don't really care if a 20-year-old can tell the difference. Not that jangling keys would be considered a musical instrument. Don't really care = not willing to spend money to make it possible.

All that said, the 12 KHz tinnitus in my left ear keeps reminding me what 12 KHz sounds like. I can hear that frequency well enough acoustically that I was able to figure out the tinnitus pitch by comparing it with a tone generator (in headphones, played loud).

Probably the highest musical sound is a triangle strike, which I expect includes harmonics well into the ultrasonic range. And there's that Swedish magazine that uses a recorded mechanical metronome to test high-energy transient capabilities that go hand in hand with high frequency capabilities. So, I see no harm in playing with stuff to reach into those frequencies, but for music listening by real humans I think it's largely irrelevant.

Rick "who has heard MP3 artifacts that sound like a an overly compressed JPG file looks when viewed up close, so it must be lower down than 15 KHz" Denney

 

[weasels]

Personally my hearing is done by 17k at best so yeah I don't worry about it.

Lucky you. I top out around 15k.

 

[paulraphael]

I've tested myself and can't even detect anything above 15.5 khz. Not even if I crank the level up to a point that I fear might drill a hole in my brain and break the wine glasses across the room. So pretty confident I'm not benefiting from anything in the music up there.

 

[sergeauckland]

So any DAC producing distortion below -70 dBFS is a good one?

Good enough. There's no reason why a DAC shouldn't be a lot better, as these days the silicon has a lot lower distortion. Consequently, a DAC that only gives -70dB distortion when the silicon gives -100 dB or less shows sloppy design, but as far as audibility goes, -70dB is adequate for transparency, which is all I care about.

S

 

[Wes]

I was only enquiring to see if you had anything of substance to say on the matter.

The substance is to not make claims that are not supported. The S in ASR stands for science. And, as you may know, there are lots of audiophool "haters" out there who would just love to poke at this site.

So I suggest using words that scientists use, like "likely," "shows" instead of "proves," "suggests" and etc.

 

[Robin L]

On the one hand, my hearing is limited to about 11khz.
On the other, I know the difference between the sound of a guitar, trumpet, drum, voice and a recording of the same.
There's some "X" factor that's important, but I'm pretty sure nobody really knows what that difference is.

 

[andreasmaaan]

The substance is to not make claims that are not supported. The S in ASR stands for science. And, as you may know, there are lots of audiophool "haters" out there who would just love to poke at this site.

So I suggest using words that scientists use, like "likely," "shows" instead of "proves," "suggests" and etc.

How would you rewrite my post in accordance with your suggestion?

Here is my post, and your post to which it was responding, again:

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?

 

[Geert]

On the one hand, my hearing is limited to about 11khz.
On the other, I know the difference between the sound of a guitar, trumpet, drum, voice and a recording of the same.
There's some "X" factor that's important, but I'm pretty sure nobody really knows what that difference is.

11kHz is all you need, even if you take harmonic frequencies into account. Don't know where an X factor comes into play.

 

[Robin L]

11kHz is all you need, even if you take harmonic frequencies into account. Don't know where an X factor comes into play.

The "X" factor is in knowing the difference between the two. If it isn't due to frequency response, then why is it so easy to tell the difference in sound character/quality between a recording and the real thing?

 

[Geert]

If it isn't due to frequency response, then why is it so easy to tell the difference in sound character/quality between a recording and the real thing?

Because of the difference in how an acoustic instrument projects its sound into a room compared to a stereo speaker setup. And of course the microphone(s) failing to capture a perfect replica of the live sound.

 

[Robin L]

Because of the difference between how an acoustic instrument projects its sound into a room compared to a stereo speaker setup. And of course the microphone(s) failing to capture a perfect replica of the live sound.

And it's weird how there's been this rush to wider bandwidth when it really doesn't do much to improve fidelity. Yes, going through directional transducers twice seems to scramble most of the stuff that's really important. I keep waiting for microphones without plastic diaphragms to appear, something that can register sound pressure differences without plastic resonances. Of course, it gets even more messed up on the speaker end of things.

 

[ShiZo]

Personally my hearing is done by 17k at best so yeah I don't worry about it.

Same here, how old are you?

 

[Pio2001]

Your hearing test was almost surely sine waves in isolation.

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.

Here is a more general test.
WARNING - PLAY THE ATTACHED FILE ON HEADPHONES ONLY. HIGH LEVEL PLAYBACK MAY DAMAGE TWEETERS.

The attached zip file contains an audio file with two treble sweep tones from 2000 to 22000 Hz (taken from RMAA's test signal) followed by a short beep. Here is the sonogram:

Listening to it with headphones, we may hear an extra fixed frequency at 1000 Hz. This is intermodulation distortion. It happens in amplifiers, speakers, and also in our own ear.

If this frequency is present during the first part of the playback, then disappears as the mains signal disappears, then the signal doesn't create any intermodulation in our ear.

Another even more conclusive experiment consists in playing back two fixed frequencies separated by 3500 kHz, each in a different speaker in order to avoid intermodulation in the reproduction system, one above our hearing limit, one below, an see if we can hear the same intermodulation when both frequencies are below our hearing limit.
For example, say that my hearing limit is 13 kHz. First test : 8500 Hz in the left speaker / 12000 Hz in the right speaker. Second test :
12000 Hz in the left speaker / 15500 Hz in the right speaker.
But since the playback level must be quite loud in order to trigger intermodulation, this experiment is very dangerous for tweeters.
I have done it. I can hear intermodulation with both frequencies within my hearing ability. The intermodulation disappears completely as soon as ONE of the frequencies is beyond my hearing ability.

This experiment shows that a single frequency outside my hearing ability has no effect on my hearing, even when it is extremely loud.
This, combined with all other experiments comparing hi res audio vs CD audio in double blind tests (dozens of failures, only one success for one listener in one study) lead me to the conclusion that frequencies outside my hearing ability for pure tones don't matter for me.

 

[paulraphael]

I wonder if we're even measuring the right thing when we look at the upper limit of our hearing. When I say I don't hear anything above 15.5K, I'm really saying my hearing is at (essentially) minus infinity decibels at 15.5K. I assume that when this cutoff frequency drops from (say) 18K to 15K, it's accompanied by some dropoff at 8 or 10 or 12K. This, even if it's just a few db, is probably responsible for our practical decline in hearing performance. Does anyone have sources on this phenomenon?

 

[Robin L]

I wonder if we're even measuring the right thing when we look at the upper limit of our hearing. When I say I don't hear anything above 15.5K, I'm really saying my hearing is at (essentially) minus infinity decibels at 15.5K. I assume that when this cutoff frequency drops from (say) 18K to 15K, it's accompanied by some dropoff at 8 or 10 or 12K. This, even if it's just a few db, is probably responsible for our practical decline in hearing performance. Does anyone have sources on this phenomenon?

All I know is the last time I heard a 20hz/20khz sweep via headphones my sensitivity increased around 8khz-10khz, then turned into fizzy buzzing around 11khz and then clean disappeared.