Natural Science Forum / Physics / Acoustics / January 2005

I am an amateur photographer
I am trying to figure out how to photograph a soundwave
suggestions are very welcome
thank you

I suppose this is an easy question for some, but I'm trying to
calculate in dB, the amplitude of a recorded WAV sound file. Is this
possible? How can it be done? Are there any libraries/APIs that do
this?

Hey there, I'm just wondering what schools offer acoustics graduate
programs in Canada. I've seen lots in the States and Europe, but I
would really like to know if there are schools in Canada that have
acoustics.

that's it only mcgill and waterloo? that is sparse. Is Canada really
not that big into acoustic education?
I was looking at schools like penn state, technical university of
denmark and university of southampton - they seem to have well

I'm not near a pool or anyplace else to do the simple
experiment, but I'm hoping someone here can help.  This
is from a scene in a movie and it seemed physically wrong:
Some divers are underwater, completely submerged, about 3 to

Thanks Noral!
In fact, I had in mind non acoustical louvers. Just ordinary ones. I thought
it could give me some dBs...at least for a noise source that you can't
directly see from outside.

where to find them?
Thanks

has anyone an idea or a way to calculate the noise attenuation provided by
louvers, such as the one used in industrial buildings? I would expect more
attenuation at higher frequencies than at lower.
Thanks,

Haldo!
I'm trying to calculate the resonate frequency of a police whistle...
You could generalize the problem to a resonating hollow sphere or cube.
Any ideas?

I am wondering if anyone has some thoughs on the prediction of the
sound field in a long narrow corridor.
Any thoughts on prediction of the SPL in this type of room would be
welcomed.

One day, a primary school child asked me that can we talk under water.
Actually, I dont know how to answer him.  Sound freq. is a
characteristic of a sound source and it remains the same in different
propagating media. Then I think, what we heard in air would be as same

A collection of products with some rather interesting claims:
The Hallograph Soundfield Optimizer
"The Hallograph breakthrough technology is the result of over 10 years
of research that studied the effects of the speaker/room interface. We

Happy new year to all.
I need to find a relationship between acoustical and electrical power,
respect to a sound reinforcement system.
Thanks and luck

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The Pentagon has admitted that the U.S. intelligence agencies called the
N.S.A, C.I.A., and Cointelpro has the technology to pick up the private
thoughts given by individuals in the vibrations produced by the brains
electrical impulses, and that these thoughts can be broadcast ...