|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
75.0.6.30
In Reply to: RE: here is,, to get yourself a start of education... posted by MC-SACDs on March 23, 2009 at 14:58:49
He's a downer and he will bring you down if you let him.
And what you said made perfect sense to me and it does to Allen as well, as we perceive ultrasonic frequencies but they are not turned into sound but registered by the brain.
The cochlea - a spiral-shaped, fluid-filled inner ear structure; is lined with cilia (tiny hairs) that move when vibrated and cause a nerve impulse to form. These vibrate up to 80,000 times a second or 80kHz. The highest audible "sound" that can be "heard" is around 27kHz and that is when you are a teenager as you get older you start to loose upper hearing and many older adults are lucky to hear to 15kHz. But even if hearing is damaged in the audible range, in the super sonic range we usually can still respond up to the full 80kHz.
The ultrasonic frequencies are so safe from damage that many "deaf" people can now perceive speech by transposing it to the ultrasonic range. This is still in the experiment stage, but this is a very promising field of study and would have many positive benefits to mankind.
You are correct Allen has confirmed the importance of the frequencies between 50kHz - 100kHz by the removal of the 50kHz filters on SACD players thus restoring their 100kHz frequency response.
Give me high resolution or remain silent,
Teresa
Follow Ups:
nt
Best Regards,
Chris redmond.
"The highest audible "sound" that can be "heard" is around 27kHz and that is when you are a teenager as you get older you start to loose upper hearing and many older adults are lucky to hear to 15kHz. But even if hearing is damaged in the audible range, in the super sonic range we usually can still respond up to the full 80kHz."
Perhaps an explanation (or a reference) is in order that explains how one responds to "sounds" that cannot be "heard".
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
I agree...a reference would be helpful.
Supersonic refers to speed beyond the speed of sound and really isnt related to the cochlea with regards to the mechanics of hearing on a day to day basis.
"We can still respond up to the full 80kHz" really requires a reference.
navman
Say two sound sources: A and B, both generated pure tones above 20 kHz at frequency f(A) and f(B), respectively. For most people, if you play one source at time, they will not be able to hear.
Now if you play two sources A and B at same time, then they one can hear. The superposition of f(A) and f(B) can form a wave at fundamental freq below 20 kHz. There are three parameters in each f, called amplitude, phase and frequency. For these two sources, if you vary those 6 parameters, you can hear various tones.
Now if there are 10 instruments played in the stage that output some harmonics modes above 20 kHz, that catched by mic in recording….. this is why you need your system to reproduce those higher freq modes….
Hope this is helpful.
so you are saying that 2 (or more) ultrasonic sources interact in such a way as to create an audible tone under 20 kHz.Great. I can believe that. Guess what. That audible tone will be captured by a normal microphone and will be reproduced by a normal non-ultrasonic system.
You don't need to reproduce ultrasonics at all to capture this alleged effect.
Give me low resolution or give me death!
Edits: 03/25/09
"Say two sound sources: A and B, both generated pure tones above 20 kHz at frequency f(A) and f(B), respectively. For most people, if you play one source at time, they will not be able to hear. Now if you play two sources A and B at same time, then they one can hear."
This is a plausible hypothesis. Do you know if tests like this have actually been published? It would be interesting to know how loud the test signals need to be to provoke sufficient non-linear distortion in the ear for audibility of the beat tone.
If you try tests like this, take care not to burn out your tweeters in a quest to hear something. This kept me from trying the test at any significant volume level, so I was not able to hear any beat tones, except when I artificially introduced them by mixing the two tones in one channel and deliberately introducing distortion using SoundForge.
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
sorry my mistake on this test. YOu do need a lower fundmantal f.
Using a woofer as a source of f below 20kHz, say at 5 kHz. And make sure two tweeters are close enough (and paralle each other). then hear the sound tone's change as vary the paramenters of f(a) and f(b) sournces....
responding to two seperate frequencies (above 20kHz) that produce a sound wave below 20kHz is a function of the hearing apparatus operating within it's biological design. Makes sense. Also makes sense that one should have teh ability to record sound waves beyond the usual human hearing.... however this has nothing to do with hair cells in the cochlea vibrating at 80kHz. That part sounds a little fantastical, unless there is a reference.
BTW you still trolling? Register. What are you afraid of?
----------SACD trolls squel like stuck pigs.
navman
I never said people in general can hear ultrasounic... read my posts very carefully.
Regarding a reference, I already sited you some materials to read and learn. here is another one:
http://www.earthworksaudio.com/tech/world_beyond_20khz.pdf
once again at you
I never said you said "people in general can hear ultrasonic..." read my post very carefully.
On the other hand when you say "read my posts carefully" which posts are you alluding to?
-----------SACD trolls are strange shadowy trolls.
navman
nt
Best Regards,
Chris redmond.
Wasnt that MC SACD teaching ultasonic theory a while back?
Gawd. You are not making sense again.
navman
We need thousands more SACD lovers to come to the Highway to shame you away from ever trolling here ever again.
Give me high resolution or remain silent,
Teresa
"as we perceive ultrasonic frequencies but they are not turned into sound but registered by the brain."
Unfortunately, audio reproduction is all about how a system sounds, which is why SACD has sunk, apart from two or three die-hard enthusiasts in a rickety old caravan!
Best Regards,
Chris redmond.
"Unfortunately, audio reproduction is all about how a system sounds...."
I do not think you understand the "system sounds"
the music sound waveforms consist of all the higher frequencies modes, some of them are way beyond 20 kHz. This has been known for long time. Although Sony/Phillps came up SACD extened to 100kHz products only about 10 years ago, but they started working on this way over 20 years....
Do not act like you are smarter than others...
Still LOL!
navman
Post a Followup:
FAQ |
Post a Message! |
Forgot Password? |
|
||||||||||||||
|
This post is made possible by the generous support of people like you and our sponsors: