The function generator/tweeter test shows I hear nothing above 18 kHz. I also made a test with analog synthesizer emulation with the Native Instruments reactor. 88.2 kHz with internal rate 176.4 kHz, 96 kHz with internal rate 192 kHz. 196 kHz and 176.4 kHz with internal = external sample rate. I heard a difference between 88.2 kHz and 96 kHz, but no difference between 96 kHz and above.
The father of my brother in law worked in the aerospace industry and he said for extremely high qualitiy application they take fs = five times the highest frequency that is relevant. 5 x 18 = 90. Perfectly fits.
The father of my brother in law worked in the aerospace industry and he said for extremely high qualitiy application they take fs = five times the highest frequency that is relevant. 5 x 18 = 90. Perfectly fits.
I didn't download the file. I know I can't hear 21k and that if I played the
file and could hear something, that it would most likely be IMD sidebands.
I do think that there is some crusade though to try to convince some portion
of population that no equipment never needs to go 1 hz above 20k and brickwall
filters are ok to put everywhere and sampling above 40k is useless.
Nevertheless, even if I can't hear above 16k, there does some to be more air,
transparency, etc. with a system that can handle much larger bandwidth.
I am simply blown away by the sound of some of the DVD-audio disc and don't
think that it is just the 24 bits.
file and could hear something, that it would most likely be IMD sidebands.
I do think that there is some crusade though to try to convince some portion
of population that no equipment never needs to go 1 hz above 20k and brickwall
filters are ok to put everywhere and sampling above 40k is useless.
Nevertheless, even if I can't hear above 16k, there does some to be more air,
transparency, etc. with a system that can handle much larger bandwidth.
I am simply blown away by the sound of some of the DVD-audio disc and don't
think that it is just the 24 bits.
And so you will appreciate my humble attempt to find a way to seperate guessing from facts. Any constructive attempts to improve these efforts are highly appreciated. Note that I'm not a digital guru, at all. 🙂
/Hugo
/Hugo
"There's Life Above 20 Kilohertz!
A Survey of Musical Instrument Spectra to 102.4 KHz "
by Caltech
http://www.cco.caltech.edu/~boyk/spectra/spectra.htm
Anyway, I used my earphones and cranked up the volume all the way up but couldn't hear anything.
A Survey of Musical Instrument Spectra to 102.4 KHz "
by Caltech
http://www.cco.caltech.edu/~boyk/spectra/spectra.htm
Anyway, I used my earphones and cranked up the volume all the way up but couldn't hear anything.
My hearing limit is about 18khz on a good day. I listened to the file in winamp and could hear nothing. Listening to it through soundforge I was able to hear what sounded like a percussion tiss-ta-tiss-tiss-ta-tiss-tiss, but I think it was mostly distortion, and there were artifacts displayed in soundforge spectrum analyzer down to around 15khz which is probably what I was hearing.
The peak was like -70db over 20khz, so it was pretty low even if it was audible.
I choose 'I hear nothing' because I didn't see there was a download attached. I do believe that info over 20K makes a difference even if you can't 'hear' it.
The peak was like -70db over 20khz, so it was pretty low even if it was audible.
I choose 'I hear nothing' because I didn't see there was a download attached. I do believe that info over 20K makes a difference even if you can't 'hear' it.
Yes, but only when dangerously loud, or in direct contact with the head.
Normal hearing path of the ear doesn't normally pass those frequencies.
The inner ear (used for balance) in extreme circumstances can also hear
ultrasonic frequencies... But that part of the brain is untrained to handle
what it hears. Bad recordings stuck in that part of the brain might cause
some forms of Tinnitus.
Normal hearing path of the ear doesn't normally pass those frequencies.
The inner ear (used for balance) in extreme circumstances can also hear
ultrasonic frequencies... But that part of the brain is untrained to handle
what it hears. Bad recordings stuck in that part of the brain might cause
some forms of Tinnitus.
While I don't think that most us can hear anything above 21kHz I do think that the audio system one listens to needs to respond well above 21kHz. What gives most insturments there tonal quality is the wave shape and harmonic content they produce. If the audio signal is brick wall filtered @ 21kHz for example everything above that frequenct is lost, I'm thinking harmonics here. Also consider that any wave shape that has a frequency component above the filter cutoff will have the part of the wave form altered. Fast attack of a drum shot for example. These are really the same thing, just 2 ways to think about it.
The other part of this is that the phase relationship of a fundamental and it's harmonics will be changed as you near the cutoff frequency. This will also change the tonal quality of the insturment. It may be very small and hard to detect in a lot of cases but that doesn't make it not true.
Later BZ
The other part of this is that the phase relationship of a fundamental and it's harmonics will be changed as you near the cutoff frequency. This will also change the tonal quality of the insturment. It may be very small and hard to detect in a lot of cases but that doesn't make it not true.
Later BZ
Bzed, I believe your assertion makes a lot of sense. I think more than a system suffering from IMD. If IMD is at play and at that frequency level, that would mean we are listening to a very mediocre sound system.
I’m looking for a way to visualize what you said about truncated waves.
I’m looking for a way to visualize what you said about truncated waves.
Still an interesting article about this is:
Inaudible High-Frequency Sounds Affect Brain Activity: Hypersonic Effect -- Oohashi et al. 83 (6): 3548 -- Journal of Neurophysiology
A PDF version is downloadable at their site.
Quite thoroughly as the researcher combined subjective double blind testing with more objective data which they got with EEG and PET-Scans.
Hi Netlist,
Thanks, I can play the files. That's not the problem though. I just don't have any speaker driver I believe to be capable of reproducing much above 20-25khz. And i have no microphone with which i can measure to verify. The one time i did such a test was with a dmx6-fire sound card which should be good to about 48k. I seemed to be able to hear clearly up to about 23k but above that it started to sound diffuse and i was no longer able to spot the source of the sound whereas below i could clearly identify the loudspeaker as the source. Same problem though: no possibility to verify whether i could no longer hear the sound or the loudspeaker just couldn't reproduce it anymore.
How do i know i get a headache above 20k? you know those ultrasonic devices used to scare cat's away from the little fish in the pond? they scare me away as well... (please don't tell my girlfriend, she'll have one installed in the bedroom...)
grtz
Joris
Thanks, I can play the files. That's not the problem though. I just don't have any speaker driver I believe to be capable of reproducing much above 20-25khz. And i have no microphone with which i can measure to verify. The one time i did such a test was with a dmx6-fire sound card which should be good to about 48k. I seemed to be able to hear clearly up to about 23k but above that it started to sound diffuse and i was no longer able to spot the source of the sound whereas below i could clearly identify the loudspeaker as the source. Same problem though: no possibility to verify whether i could no longer hear the sound or the loudspeaker just couldn't reproduce it anymore.
How do i know i get a headache above 20k? you know those ultrasonic devices used to scare cat's away from the little fish in the pond? they scare me away as well... (please don't tell my girlfriend, she'll have one installed in the bedroom...)
grtz
Joris
Joris, these people tend to believe that most (even cheap) speakers are able to reproduce these high frequencies. A good headphone should do. Be indeed careful, the file has a average RMS power of -56db. But if you crank up the volume too much it might be harmful. Best listen to it with some kind of visible aid like a VU meter.
I played it back through my ultra high resolution directly heated triode SE amplifier and EnaBabbled full range hemp cone speaker and my girlfriend could clearly make out the instruments playing from the kitchen.
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.
I had a similar experience in Japan in my younger days. The ultrasonic sensor system used to automatically open doors into the subway station gave me a huge headache. I started walking to other stations just to avoid it. These days, it's probably a moot point for my now-too-old ears.
Awfully thin stuff.
I had a similar experience in Japan in my younger days. The ultrasonic sensor system used to automatically open doors into the subway station gave me a huge headache. I started walking to other stations just to avoid it. These days, it's probably a moot point for my now-too-old ears.
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