Sensing Ultrasonics

[Zensō]

I found this video very interesting. I’m wondering how it relates to high resolution audio.

 

[pfzar]

Having worked with parametric speakers, you are hearing the foldback distortion caused by the brick-wall filter for the carrier freq. The eardrum does not move when presented with a 40k tone.

the 40Khz tone is in most applications has a SPL of 135 to 140 dB. OSHA has a cap of 140dB.

 

[Wes]

define "hear"

if you are asking if humans can perceive freqs. beyond 20 kHz, then define perceive...

if you are asking if humans can be affected behaviorally by even rel. low level freqs. beyond 20 kHz, then the answer is yes

 

[Kal Rubinson]

if you are asking if humans can be affected behaviorally by even rel. low level freqs. beyond 20 kHz, then the answer is yes

Do you have a confirmed scientific reference for this?

 

[Wes]

I used to - but let me see if I can dig it up. BTW, not talking about cochlear routes only...

 

[Wes]

is Pumphrey's the earliest?
https://www.nature.com/articles/166571b0

 

[Hayabusa]

Multiple ultrasonic high level sound sources can produce audible (< 20kHz) sounds.
As far as I remember from test being done in 80's its because of non-linear behaviour of air at these levels.
I wonder if this also the case in this experiment.

 

[Hayabusa]

Multiple ultrasonic high level sound sources can produce audible (< 20kHz) sounds.
As far as I remember from test being done in 80's its because of non-linear behaviour of air at these levels.
I wonder if this also the case in this experiment.

reference: https://hackaday.com/2019/02/14/creating-coherent-sound-beams-easily/

 

[tvrgeek]

Same video posted here before. Search for comments.

 

[Zensō]

Same video posted here before. Search for comments.

Thanks for the heads up. Ran a search and didn’t see it...

 

[Kal Rubinson]

is Pumphrey's the earliest?
https://www.nature.com/articles/166571b0

Possibly but it is anecdotal and he does some reaching. Note he says:
"As the frequency was varied continuously
from 12 to 100 kc. /s ., the pitch rose with it to 15 kc./s. and stayed there as the frequency was further increased."
Could be intermodulation and excitation of resonances in the physical structures of the head.

 

[Wes]

yup - we could see who cited him

 

[pozz]

is Pumphrey's the earliest?
https://www.nature.com/articles/166571b0

This specific article is not even a page long and was discussed in this thread: https://www.audiosciencereview.com/forum/index.php?threads/two-old-ess-talks.9216/page-2#post-240851

The linked post has the exact page.

These claims have been thoroughly debunked multiple times. There is no physiological mechanism for hearing ultrasonics. The most I've seen about this (in Moore's book) is that infants have an upshifted hearing range that settles in the typical range as they get older.

 

[Wes]

I said nothing about hearing.

check out my exact weasel words above

 

[restorer-john]

There is no physiological mechanism for hearing ultrasonics.

Have you ever put your finger in an ultrasonic cleaner? Ouch.

 

[Zensō]

Have you ever put your finger in an ultrasonic cleaner? Ouch.

I have (an old pen & ink draftsman here), and yes it’s an uncomfortable sensation. I also spent an evening watching hundreds of thousands of bats feeding, which was a somehow related experience.

 

[Kal Rubinson]

I said nothing about hearing.

check out my exact weasel words above

Indeed. That would include the so-called "Brown Note."

 

[pozz]

I said nothing about hearing.

check out my exact weasel words above

By sheer SPL? Not much to do with audio then.

 

[Wes]

not necessarily - if it can be "sensed" (see the OP) then there may be an effect on sound, just as a nice whiskey or looking at art can alter perceptions of SQ

I'd argue that synesthesia is an important factor on car audio also.

But, the importance of any putative would likely be about at the level of a phaat interconnect cable...

 

[Head_Unit]

Could be intermodulation and excitation of resonances in the physical structures of the head.

I'm pickin' up good vibrations
She's giving me [ultrasonic] excitations