Natural Science Forum / Physics / Acoustics / November 2006

Is it possible for a phonon that 10^10,000 Hz [thats
10-to-the-power-10,000 hz; or 10 followed by 10,000 zeros] to exist in
Earth's atmosphere?
Thanks,

Help!
I'm trying to solve the non homogeneous equation by separation of
variables:
U_xx + U_yy = x+y

Materials based on wool, paper, and plant products are currently being
promoted as alternatives to mineral fibre (glass wool and rock wool) for
thermal insulation.  It is stated that their manufacture causes lower carbon
emissions and they are less irritant.  However I have not seen ...

I apologize deeply for any annoyance caused by my persistance on this
topic.
What would happen to the left cochlea of a human if it was exposed to a
140 dB, 50 kHz sine-wave tone? My guess is there would be excruciating

If I have two acoustic sources transmitting the exact same signal
(perfectly correlated), i.e., a stereo system playing a monaural
signal, then what total power would be perceived at the listening
position without accounting for path loss? Let's say each channel

What conditions are required for there to exist a coherent acoustic
pure sine-wave tone that is 140 dB and 10^1,000,000,000,000 Hz [i.e.
10-to-the-power-1,000,000,000,000 Hz, or 1 followed by
1,000,000,000,000 zeros]?

Can anyone tell me how a noise suppressor for a turbojet engine works?

If you have a cone, like the attachment to an old record player, what
actually causes the amplification ?
Steve M

Lets says there is a sine-wave tone that is around 140 dB and in close
proximity to a human ear. How high of a frequency would this tone need
to be in order not to harm the human ear?
The human hearing range is from 20 hz to 20 khz [little kids can hear

Is 50 khz a high-enough frequency for 140 dB to be safe for the human
ear? If not, then what is lowest-frequency [above 20 khz] in which
close-range 140 dB will not cause acoustic trauma to the human ear?
Thanks,

Dear Group:
    A recurring problem in the US is to determine a sensible prescription
for  the noise isolation achieved in a in luxury condominium. Sound
isolation the ASTM "STC" and the parallel ISO "Rw" apply to airborne

For the benefit of the other long time usenet participants who may not be
aware, Google has started putting many of the usenet groups into a webpage
format.  You can find this one at this URL
http://groups.google.com/group/alt.sci.physics.acoustics

I am designing a quiet aircraft at university and I have found a lot of
articles on the use of exhaust chevrons with a saw-tooth trailing edge
shape. I understand that they reduce turbulence between the jet exhaust
flow and external airflow. However, I have no idea how this reduces ...

Coul someone give some calibration labs in new york, new jersey,
please. Thanks and luck

What is the highest-frequency sound possible in earth's atmosphere?
What is the highest-intensity sound [in decibels] possible in earth's
atmosphere?
Thanks,