Re: Sonic info & links

Bill Wallace ( (no email) )
Sun, 13 Sep 1998 02:30:02 -0400

For the purposes of architectural design, the Sabine coefficient (calculated
from reverberation chamber measurements) is preferred. Interestingly some
absorbent materials are found to have a Sabine coefficient in excess of
unity at higher frequencies. This is due to edge effects and when this
occurs the value can be taken as 1.0.

Could someone explain this more clearly, it comes from the acoustic faq,
thanx.

>Shuman Resonance. This is the frequency at which the Earth's magnetic
>field resonates when excited by a powerful enough force. The first one I
>learned about was lightning. I then looked further into this phenomenon
>and found that tornadoes also cause this resonance to be excited, but
>surprisingly enough in the air. Just before a tornado forms an 8Hz tone
>is heard. This was discovered by a group of geophysicists who were using
>listening devices for detecting, of all things, earthquakes, which also
>happen to cause a resonance effect of 8Hz, both electromagnetically and
>acoustically. Volcanoes also tend to excite this resonance before
>erupting.
>
>
>Physics of Open Ended Tubes
>http://www.geocities.com/Vienna/3941/oetubes.html
>
>Physics of Closed End Tubes
>http://www.geocities.com/Vienna/3941/closedend.html
>
>
>
> -------------------------------------------------------------
> To leave this list, email <listserver@dallastexas.net>
> with the body text: leave keelynet
> WWW based join and leave forms and KeelyNet list archives
> are at http://dallastexas.net/keelynet/
> -------------------------------------------------------------
>