Natural Science Forum / Physics / Acoustics / July 2004

Anyone know of a software that can get the level profile of a wav file. In
order to visually demonstrate how the level (LAeq) changes with time for a
certain sound recording?
Thanks!

Does anyone know the speed of sound in bulk materials like aluminum
and PZT?
I want to make an experimental 15 kHz transducer  that uses a 1/2
wavelength  piece of  PZT and a 1/4 wavelength aluminum plate. Any

Is anyone aware of work measuring and controling the
acoustic impedence of aerogels?
Thanks,
Bob

I've recently been investigating a private noise complaint using FFT
and have found tones at 50Hz and 14.2kHZ.
These tones are inaudible to me despite being approx 80dB at the
suspected noise source, and only 15dB at 14.2kHz at source. At the

Greets to All
I'm trying to find out if it's possible to mix water or have water turn in a spiral shape using just sound and if so how?
TIA

Hi group, I have been lurking for a while...
I am wondering if any of you have ideas for noise reduction in food
industry, specifically in relation to reducing reverberation in food
manufacturing/slaughter areas. These surfaces require daily washdown with

I'm looking for a good method of bonding thin (.003-.025") Lithium Niobate
crystal wafers to gold coated fused silica prisms. We have used UV curing
cements with some success, but I understand that a metal to metal bond is the
preferred and most efficient method.

I am looking for references to studies regarding the perceptibility of noise
level changes specifically in relation to traffic noise.  Typically a 3 dB
change is identified as a threshold of perceptibility but I have seen levels
between 1dB and 5dB identified as well.  However, none ...

If I have a sandwich-construction made of two wooden layers, each with an
isolation value of 2dB, and an inner PVC-barrier with an isolation value of
40 dB (values given for 7000 Hz), what would be the total isolation value of
such a construction? How do you make this kind of ...

Hi All,
I am a sound engineer and am interested in environmental noise
monitoring.
I wonder if anyone could recommend texts or websites on learning more

vediamo un po se riusciamo ad animare un pochino questo newsgroup che mi
sembra un po morto!!!
Volevo chiedere se qualcuno sa dirni la differenza sostaniziale, come
previsto dal regolamento della merloni, tra studio di ipatto ambientale e

Here I am again troubling you fine folks with one of my questions.
The equation for the Schroeder frequency of an enclosure is
f(sch) >= 2000*sqrt(T60/V)
where T60 is the 60 dB reverb time and V is the metric volume of the

Hi
I have recently been given the task of assisting with the spec, design
and construction inspection of an outdoor sound system. For a
performance stage in an open park.

I am looking for a Tutorial paper on Acoustics Echo Cancellors and
various techniques used for it.
Could you give me some pointers or send me some papers.
Thanks

Hello colleages,
I got a little project with appartments close to a harbour. I have to
evaluate the sound levels in case of a cargo is "parked" just in front
of these appartments. Does anyone have sound date, Lw og Lp in octave