What do you hear above 21Khz?

[Robski666]

I'm not really convinced that the test is valid (and no I'm not being smart) I sure as heck can't hear 21Khz but there are a few unknowns in the chain.

I would look at it another way with an analogy say you have a pair of 'cheap' head phones that reproduce up 16Khz and you listen on a good headphone amp and DAC with a good recording. Then listen to a pair of quality headphones that say can reproduce out to 38Khz.

Well we can't hear out to 38Khz but the better headphones will be able to articulate the detail much better, as well the better headphones will be able to reproduce material with fast rise time wave fronts (complex combination of LF and MF and HF spectra) E.G. a well recorded door slamming closed 😉

In a similar way the small difference portions would add and subtract form the rest of the original wave form to add to the sonic spectra sometimes in not so obvious ways, sometimes profound ways.

Some people have already indicated that there are spectra well beyond the nominal 20K limit from certain instruments hence the difference between a well recorded 24/96 and engineered piece (or better) and of course to really hear the difference you need very good equipment and to appreciate it a good pair of ears.

Just a thought.

PS

Some of the differences could just be artefacts from re sampling as well

 

[sendbox]

I can hear, but somthing is not right.

Well, I tried Difference.wav with Winamp and headphone.
I can hear music, with background high pitch sound zzzzz.........

However, I do not think I can actually hear 21KHz.
The high pitch noise may caused by the hard disk noise to read the data out of disk.
I always hear the sound while listening music out of hard disk drive.
BTW, in winamp equalizer’s high band graph is synchronized with the bits I hear.
I use the volume as the same as my daily level (so it is not clipping noise).
Now I am confused. I think I never can hear 21KHz. The rhythm does not sound like high frequency at all. It is more like a rap. What is it?

 

[Netlist]

I have lowered the pitch of the file so that the information is now located between 9,5 and 23KHz for comparison with what you think you hear in the Difference.wav file.
It is amplified with 25dB and the average RMS power is now -33dB
No need to crank up the volume anymore.

DifferenceLowerPitch+25dB16.wav

/Hugo

 

[jhmee9]

...of course.....I can hear up to 25kHz.....maybe 25,5kHz.....

cheers,
"Batman"...😀

 

[Jakob2]

It is interesting that Oohashi et al. skimmed right past a huge problem- they could not get the same effect with their loudpeakers and their headphones. Woops. Perhaps that was the reason that they couldn't get a peer-reviewed paper into JAES, just a preprint. They were able to get stuff published in some neurophysiology journals, where presumably the referees were not as familiar with the problems of practical loudspeakers fed with high levels of ultrasonics...

Awfully thin stuff.

<snip>

I´ve reread Oohashi´s et al. AES preprint from 1991, their article in the journal of neurophysiology, their presentation from the Auditory Display and finally their article from brain research that you cited. The last one i didn´t know so far.

In the first three papers the authors described their reproduction sound system and i couldn´t find any reference to earphones/headphones.
It seems that their work was exclusively done with usage of a loudspeaker system.

As the ´hypersonic effect´ found is in contradiction to the known mechanism of the normal auditory system the authors studied possible other sensing mechanisms in more experiments and in these experiments, described in detail in no. 4), they found that the hypersonic effect couldn´t be evoked if the full range signal was presented by earphone/headphone alone.

It might be the language barrier, but i think this is a totally different thing then that what you´ve said above.

The authors did include several controls, did undertake some efforts to find correlation between subjective and objektive evaluation, did supply some explanations why their results could be different compared to other studies done before and finally even did some additional experiments to verify their findings.

Of course it raises some questions, and in some points i´d like to have more measurements in higher resolution, and surely additional research is needed, but in what respect is this `awfully thin` or totally flawed?

1.) High-Frequency Sound Above the Audible Range Affects Brain Electric
Activity and Sound Perception
Tsutomu Oohashi et al.,
AES convention preprint 3207, 91st convention, New York 1991

2.) Inaudible High-Frequency Sounds Affect Brain Activity: Hypersonic Effect -- Oohashi et al. 83 (6): 3548 -- Journal of Neurophysiology

3.) Proceedings of the 2002 International Conference on Auditory Display, Kyoto, Japan, July 2-5, 2002
Auditory Display for Deep Brain Activation: Hypersonic Effect; Yagi et al.

4.) The role of biological system other than auditory air-conduction in the emergence of the hypersonic effect.
Brain research 2006;1073-1074():339-47.

Wishes