supposed hearing limit of 20khz is b.s., just saying

[UltraJv]

You surely have an "interesting" point of view about what 'scientific' means. No coffee and doughnuts required - some real data will suffice, thanks.

+1

[UltraJv]

And after all this "research", all you can come up with is (paraphrased): "All the folks in my office could hear a 25kHz tone by blasting it with 116dB at a certain angle into their ear"? Right. Very scientific!

Would you prefer I put some fancy acronyms and extra fanfare with bright ribbons and pastel balloons in there? Maybe a pull my report out from a nice attache' case in front of the judgement panel?

Honestly. You have a problem because I put my findings in a one-sentence summary readable by the general public? Wow, ok boss. Maybe if I served my findings with coffee and doughnuts I'd get a more positive response.

not quite.

If you go around making general assertions that 'all audiologists hold to the 20Hz to 20kHz dogma' don't be surprised at the kind of response you will get. Meffy has suggested some good resources that can be used to test the scenario you are proposing here. All I perceive from this thread is that you really have no idea what science actually involves...

+1

[rifftrax]

You surely have an "interesting" point of view about what 'scientific' means. No coffee and doughnuts required - some real data will suffice, thanks.

Hmmm, so let me get this straight.

I have a number of high-power ultrasonic transducers that I've determined the best instances output 110db @ 25.1khz @ 1 meter (they are paired with built-in amplifiers at the point I'm testing them). I have a Dayton Audio EMM-6 measurement microphone which was calibrated against a very expensive reference measurement microphone by Spectrum Labs and was supplied with an on-axis response file detailing frequency deviation to a hundredth of a decibel up to 25khz (which microphones have also been shown by people like Ethan Winer to have near the exact same pin-point accuracy as say an Earthworks M30). This microphone I took relative measurements with into a DAW using a Nady SMPS-1X phantom power supply (very high-bandwidth specification) running to an EMU 0202 set at a 96khz sample-rate. I used a Class II decibel meter in an open area (cleared out portion of our warehouse) to measure the output of a 1khz sine tone to find the absolute decibel level after which I would re-position the Dayton Audio EMM-6 in the exact same place and correlate the relative decibel level in-DAW to the absolute level to check what the recordings meant in terms of absolute decibel level. All materials were allowed to stabilize at a nominal room temperature of about 70 degrees F before taking calibration measurements which I then checked per device being used with an infrared thermometer to ensure results wouldn't change based on environment.

Then I measured the output of the each transducer which was positioned on a specific stand I created to allow as close to perfect on-axis positioning of the devices possible and had those aimed directly towards the then stand mounted Dayton Audio EMM-6. I recorded those measurements in a very quiet room (35db absolute ambient noise level) into my DAW (I'm using FL Studio for convenience) @ 96khz sample-rate and then into Edison and WaveCandy using both the high-resolution meter, spectrogram and waveform views to verify the frequency response, waveform type and decibel level (relative and absolute) of each transducer.

I then compared my measurements to holding certain transducers at half the distance to my ear (which I also checked and verified would account for exactly a 6db increase, per the devices being a point-source) and found that I was able to hear the devices very clearly. This is occurring at around 112db - 116db depending on the actual output quality of the transducer (varies slightly overall). Spectrogram measurements and measurements through Voxengo's SPAN (set to show the slightest potential harmonic content by raising the lowest level on the graph's resolution to -95db relative volume) confirm almost a complete absence of any effective harmonic content (minus a low-level 100hz emission from most transducers). All spectrograms/frequency response charts were set to display up to nyquist for my sample-rate (i.e. 48khz limit).

I then checked with everyone in my office to verify they could (at a distance of approx 1.5 ft. with the transducers angled towards their ear) detect the sound (which each person verified).

So apparently that's not good enough for you? Should I put on a white lab coat while I do it? Would that help? Or maybe you're just waiting for the pretty graphs for confirmation (coming soon as I mentioned). I'm definitely open for suggestions about what you think I could improve here. Please, your feedback is so valuable.

Or maybe what you're saying is that isn't actually real data. Egad! How could I have not seen it before! Well, it is entirely possible that I do live in the matrix so you could be right that my "data" may very well not actually exist! Brilliant. I think you're onto something here.

[Kriminal]

lets say your test is accurate and some ppl can hear that frequency assuming they are in your lab using whatever specialist audio output device you use...what use is it scientifically or otherwise?

[UltraJv]

Its a wind up - no one could be that deluded. Just a case of Im right and the rest of the world is wrong, y'know what kids are like

[rifftrax]

Its a wind up - no one could be that deluded. Just a case of Im right and the rest of the world is wrong, y'know what kids are like

Glad to see you are just as convinced as you've described that your predilections are iron-clad. It's obvious you're the one who's refusing to consider anything that seems contrary to what you've already assumed is the case.

I'm the one here providing a case and evidence (also, I fail to see how what I described above isn't a scientific method of testing that doesn't provide reliable evidence) and saying I will bring evidence to back that up. All you're doing 1-upping posts that say "where's the data" when I've already said that when I go back to work on Monday I'm going to be supplying that to this thread. If you don't know how to wait 2 days then obviously you are beyond help.

Hey, but don't let me rain on your parade. Naturally if you just really abhor the thought that a majority of people hear above 20khz with 110+db tones that much then no-one is going to tell you otherwise. There are plenty of other threads that would likely pander to your bias which would give you that resultant warm fuzzy feeling you're looking for I'm sure.

lets say your test is accurate and some ppl can hear that frequency assuming they are in your lab using whatever specialist audio output device you use...what use is it scientifically or otherwise?

Huh? You're asking me what use is knowing more about the nature of human hearing? Well gee, uh. I dunno. What use is knowing anything at all about the nature of human hearing? How about "accurate knowledge is useful". Ultrasonic transducers are in tons of devices. Maybe it would be helpful for people to know that not everything that they hear that they can't detect the actual source of sound for it isn't an otoacoustic emission. What if you work near ultrasonic welding machines? Wouldn't it be useful to know that you shouldn't tip your head to aligning up to being close to on-axis to reflected sound coming from the sonotrode? Maybe the "redbook" cd sample-rate should be changed to 60khz. Maybe tons of stuff. There no limit to what you can potentially extrapolate from having extra information on stuff like this.

[dreamkeeper]

So apparently that's not good enough for you?

Eggsuckedlee!

[JasonSpatola]

This isn't mindblowing information.

Group 1 is saying: "hey, maybe you should be accounting for all variables and possible chinks in your armor."

Group 3 is saying: "in the best case scenario, this still isn't really news."

I think it's an interesting experiment, but I don't think you're debunking any myths. I don't think you're shattering or even mildly contradicting anyone's beliefs, either.

Does anyone in this thread doubt that the 25k tone can be perceived at over 110db?

By all means, keep posting, rifftrax. But know that most people aren't disagreeing with you - and like Meffy said, getting pedantic about your methodology isn't denying your claim or attacking you or being anything akin to ludditism or anti-science bias (quite the opposite).

[JasonSpatola]

Apparently it does, the white paper by Tsutomu Ōhashi contained extremely detailed tests involving playback of recorded gamelan music with and without 20khz+ content which showed additional enjoyment (measured by increased brain activity in particular areas) which correlated to the participants own "rated" subjective measurements of their feelings about what they heard and how enjoyable it was to listen to.

So, yes. I believe it does. Unless you want to refute his white paper.

Well, keep in mind that when considering the Ōhashi data to consider
http://www.nhk.or.jp/strl/publica/labnote/lab486.html

Best wishes in your endeavors.

[dreamkeeper]

Does anyone in this thread doubt that the 25k tone can be perceived at over 110db?

Assuming that the OP didn't tell us complete BS, all that was shown is that people could perceive something. Whether or not that something was indeed a 25kHz tone is not proven so far.

Actually the very high SPL strongly suggests that those people perceived some side effect caused by the ultrasonic transducer, that has nothing to do with the frequency but with the sheer power of the device.

Either way... if someone would blast with an ultrasonic device into my ear like the OP describes, I'd kill them and claim self-defence.

[Josmoker]

Hi rifftrax,

interesting stuff, however I can't believe that you're saying all has been done and this is what it's going to be. The test you have done can just be the beginning of more research.
I would encourage you to actually write a white paper as proposed, but don't do it if you can't deal with the criticism you got in this thread. Because you will get much more criticism from "serious scientists" than you got here (if you're lucky, if you're not no one will care).
To find out at which SPL people actually start hearing the sound would be interesting for starters, and at which point they start crying out in pain. Then get some more people who are not your co-workers and try with them, then try to which frequency you can go before people stop hearing the sound. Go further!

P.S.: And don't expect people to greet you with open arms if you come charging in like an outraged rhino (especially not on an internet forum).

[spaceman]

Hmmm, so let me get this straight.

I have a number of high-power ultrasonic transducers that I've determined the best instances output 110db @ 25.1khz @ 1 meter (they are paired with built-in amplifiers at the point I'm testing them). I have a Dayton Audio EMM-6 measurement microphone which was calibrated against a very expensive reference measurement microphone by Spectrum Labs and was supplied with an on-axis response file detailing frequency deviation to a hundredth of a decibel up to 25khz (which microphones have also been shown by people like Ethan Winer to have near the exact same pin-point accuracy as say an Earthworks M30). This microphone I took relative measurements with into a DAW using a Nady SMPS-1X phantom power supply (very high-bandwidth specification) running to an EMU 0202 set at a 96khz sample-rate. I used a Class II decibel meter in an open area (cleared out portion of our warehouse) to measure the output of a 1khz sine tone to find the absolute decibel level after which I would re-position the Dayton Audio EMM-6 in the exact same place and correlate the relative decibel level in-DAW to the absolute level to check what the recordings meant in terms of absolute decibel level. All materials were allowed to stabilize at a nominal room temperature of about 70 degrees F before taking calibration measurements which I then checked per device being used with an infrared thermometer to ensure results wouldn't change based on environment.

Then I measured the output of the each transducer which was positioned on a specific stand I created to allow as close to perfect on-axis positioning of the devices possible and had those aimed directly towards the then stand mounted Dayton Audio EMM-6. I recorded those measurements in a very quiet room (35db absolute ambient noise level) into my DAW (I'm using FL Studio for convenience) @ 96khz sample-rate and then into Edison and WaveCandy using both the high-resolution meter, spectrogram and waveform views to verify the frequency response, waveform type and decibel level (relative and absolute) of each transducer.

I then compared my measurements to holding certain transducers at half the distance to my ear (which I also checked and verified would account for exactly a 6db increase, per the devices being a point-source) and found that I was able to hear the devices very clearly. This is occurring at around 112db - 116db depending on the actual output quality of the transducer (varies slightly overall). Spectrogram measurements and measurements through Voxengo's SPAN (set to show the slightest potential harmonic content by raising the lowest level on the graph's resolution to -95db relative volume) confirm almost a complete absence of any effective harmonic content (minus a low-level 100hz emission from most transducers). All spectrograms/frequency response charts were set to display up to nyquist for my sample-rate (i.e. 48khz limit).

I then checked with everyone in my office to verify they could (at a distance of approx 1.5 ft. with the transducers angled towards their ear) detect the sound (which each person verified).

So apparently that's not good enough for you? Should I put on a white lab coat while I do it? Would that help? Or maybe you're just waiting for the pretty graphs for confirmation (coming soon as I mentioned). I'm definitely open for suggestions about what you think I could improve here. Please, your feedback is so valuable.

Or maybe what you're saying is that isn't actually real data. Egad! How could I have not seen it before! Well, it is entirely possible that I do live in the matrix so you could be right that my "data" may very well not actually exist! Brilliant. I think you're onto something here.

Sorry rifftrax, but nothing you've said here amounts to any proof whatsoever that what those people heard was 25khz. None whatsoever. Any scientific publication would laugh you out of the door.

[Flandersh]

I will waiting for the paper before I draw any conclusions; thought I do research on perception, I am in no way trained to do such kind of research you talk about.

The way from experiments to verified science is, as other have pointed, long. A good example of that is psi (telepathy, remote viewing, healing etc.). It exist many accounts that it seems to work, and it has been done many experiments on it (inclusive 30 years with verified experiments at Princeton University), but we have none exact science on it. We have only theories that may explain it (and that also, if right, would imply that human can hear much higher frequencies than 25 khz in some special cases).

The anatomy of ears and their possible influences on the sound you hear has been pointed out. First to take into account is that the perception of pitch will change with dB; this can make up an error in the measurements. Further, the reflections in the ear channel as mention are an important thing. In addition to being filtered and so, the eardrum will reflect back some sound at a much lower amplitude and this may modulate or affect the incoming sound. The ear has cause of this effect a chronic sound as long as the person is not in vacuum. And then we have the perception of the brain. This perception, and what being perceived of frequencies, amplitudes and not are a result of the whole wiring of the brain. Using EEG and ERP measurement one can get some sort of evidence (valid for research) of how the brain work on that matter. A last point I was thinking on is the existence of some kind of "meta-senses" in the human. If one close their eyes and I tell to point at a certain direction with their finger, most humans would fix it without problems. This implicate it is possible to orient in a room without the ordinary senses. If such "meta-senses" exist for hearing as well, I don't know, it may be something to take into account.

And when doing the research, use a soundcard with better converters than the EMU 0202 to eliminate as much unwanted test noise as possible.

[IncarnateX]

My nerves start trembling already when the pitch of my wife goes high C and that is just 1046 Hz. Anything beyond that must be a true nightmare.

[Meffy]

Since this is deteriorating into a flamewar (is anyone surprised? no?) I'm going to lock the thread for now. Rifftrax, when you're ready to "publish" your results send me a PM and I'll unlock it. If you haven't any more than "I proved it to my satisfaction" then congratulations: you are satisfied. If you want to go further than that, contact a scientific journal and publish your findings for real. Rattle the very foundations of science.