Natural Science Forum / Physics / Acoustics / December 2005

I have a issue with predicting the noise losses along a concrete riser.
This is for a underground facility that has some huge fans needing to
get air to and from the surface.
The risers are typially 3metre x 4 metres in cross section and vary in

In some experiment, we want to stimulate some whiskers of an immobilized rat
with a high frequency (600Hz max) stimulus. I looked at piezos, but they are
really expensive for a simple pilot experiment.
Then I thought: since I am already equipped to do sound stimulation,

am just a physics student.  When a free-on-both-ends object like a
baseball bat(is it considered free if you are holding at one end?) is
impulsively struck it vibrates at its natural frequnecy.  But doesn't
it also vibrate at higher modes?  What determines how it gets to those

I have a situation where I am going to have to rely on wave files
recorded on a laptop computer to get spectral data of noise in a power
plant. Don't scoff - you work with what you have! (My informant will
also make simultaneous A-weighted SPL with an accurate but simple

I have a few questions about the clarinet I'm hoping you can help me
with.
This website shows how to simulate a clarinet -
http://www.phy.mtu.edu/~suits/clarinet.html

I am really confused with something which is probably too basic for all
of you but ... I could really use your help.
I was checking out a computer program which allows you to specify the
parameters of any kind of signal going through any kind of system and

I've written a Mac OS X application called ToneTester which tests the
pitch offset between ears. I'm publishing it as open-source software,
and thought that the denizens of this group might find it interesting.
You can find the application at

I have been working in Acoustics for 2 years after having worked in IT
for many years. I note
that every SLM manufacturer whose equipment I have used has their own
propietary PC software.