super tweeters

I thought it was standard to hear up to 20KHz? I am young so I suppose I just haven't worn them in yet ;)
 
3DSonics said:
The perception of a given steady state tone (the current measure of audibility in a physiological sense)
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Whoa, that's not the only experiment that has been conducted...

is completely invalid as principle measure of audibility, EXCEPT for steady state tones.

The human auditory system is a mixture of a very unsophisticated and binary "bare" detection system (the ear - with 30+% THD @ 92db build in mechanically, using a very basic purely binary detection) with a purely "analogue computing" copmplex DSP system (parts of the brain) with a slow feedback loop (learning) build in.

To make predictions about what system 2 is capable of by evaluating system 1 is as accurate as comparing the military merit or not of a nuke vs. a crossbow on portability.....
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So what? If you're interested in evaluating "System 2", then you do so directly, skipping over "System 1" entirely. It's interesting to know how the ear works (system 1), so it's been studied.

Likewise, it's interesting to know what people can hear, and their perceptions and preferences. And that has been studied too - without resorting to inferences based on "System 1".

If you can provide an experiment which invalidates the data gathered using tones then a large number of people would find that interesting. Do you have such an experiment? I'm guessing "no" is the answer.
 
I recall reading somewhere that some guy in the US had his car stereo so loud - that when the window were shut all was ok (as the waves simply revervsed on themselves)...but when the windows were opened - serious damage was to be had to the listeners...maybe fatal....not sure if it was an urban myth tho!

and our frquency range does worsen as we get older...
 
Plenty of research shows that man is capable of ultrasonic hearing as far as I know. Tests involving bone conduction show humans as being capable of detecting sounds more than an octave above 20khz in the right circumstances.

I am not aware of any of those circumstances involving sitting in front of a hifi however. Of interest to me is that most ultrasonic sounds are perceived as being between 7khz and 12khz.
 
Hi,

oedipus said:
Whoa, that's not the only experiment that has been conducted....
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But the 20Hz-20KHz figure comes from such.

oedipus said:
If you can provide an experiment which invalidates the data gathered using tones then a large number of people would find that interesting. Do you have such an experiment? I'm guessing "no" is the answer.
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Your guess is as accurate as is the case with most "objectivists"....

Try:

Oohashi et al - Inaudible High-Frequency Sounds Affect Brain Activity: Hypersonic Effect

Ciao T
 
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Work has been done on leading edge detection. Maybe I can google a few links...
 
brizonbiovizier said:
It resonates the internal chest cavity and standing waves destroy the internal organs.
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Are you sure about that? It sounds somewhat unlikely given the wavelengths of sound in air at 7Hz (and even less likely in tissue).

The Devil said:
I think it vibrates certain internal organs to bits.
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This sounds more likely... i.e. simple vibration is the issue rather than any resonance/standing waves. Although if there is one particular frequency that is more dangerous that would suggest some sort of resonant process...

I'm genuinely interested in this BTW. I have a work interest in medical ultrasound but have never given any thought to infrasonic effects on tissue.

Tenson - when you say you can hear 20kHz how are you testing this? I have a frequency sweep track on a CD, and can hear that up to 20kHz, but listening to it on headphones it appears to be of roughly constant loudness so I guess it's been produced with that in mind? That is in terms of SPL the 20kHz signal is much bigger than that at say 2kHz. The disc I have is this in case anyone knows.
 
Just googled online to check - its between 6-8 Hz and is due to chest cavity resonance causing pressure shockwaves. Vibrating organs to bits occurs at much higher frequency.
 
brizonbiovizier said:
Just googled online to check - its between 6-8 Hz and is due to chest cavity resonance causing pressure shockwaves. Vibrating organs to bits occurs at much higher frequency.
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Shockwaves??? In the body at 7Hz??? I'm going to have to look into this properly...
 
Yup - try googling for "chest cavity resonant frequency". it would take very high amplitude of course. Some whales use a similiar principle to stun prey apprently.
 
So its just like being on the end of small, multiple explosions (i.e. 7 per second)?

An explosion kills with a sudden, massive air shockwave. A really big speaker could do the same job by creating 7 slightly smaller "pressure shockwaves" per second?

That would be a groovy weapon - bit like those sound amplifier things used in Dune!!

Cool huh!
 

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