Natural Science Forum / Physics / Acoustics / August 2004

For those who are interested, an exact mathematical analysis of the
Doppler distortion that is produced by a vibrating piston in a tube
can be found at:
http://www.silcom.com/~aludwig/Physics/Exact_piston/dopdist.htm

I'm doing TL predictions for some sandwich wall/floor constructions
and wondering if anyone has, or can point me towards, the Young's modulus
(modulus of elasticity) for some common building materials:
Concrete (2400kg/m3)

I have following confusion.
Its a fact that sound travels
fastest through(or in??) solid and
faster through (/in)  liquid as compared to its speed in(or through??)

I have provided direct experimental measurements of dynamic Doppler
shift.  I have also provided a reference to the analysis of
instantaneous dynamic Doppler shift that is given in a classical
textbook on Acoustics by a well respected and reputable author.  It is

This idea is just a trial balloon; raise it and see if anyone salutes...
I have the notion that huge, overly reverberant venues like dome
stadiums could have their 20 second reverb times reduced by the
introduction of some large weather balloons, inflated with compressed

I am searching standards for alarm clock noise measurement. Please
anyone can kindly do me a favor. Thankyou.
I got ISO3741 but it is only for Mechanical Equipment, right?
Which type (I or II) of Sound Level Meter should I purchased?

As you have seen, this debate has been going on for awhile now
(the source of which is rec.audio.tech). I wanted to get some
opinions here. What do you think - is there any physics/acoustics
involved that would preclude time-varying Doppler from a speaker

THE HYPOTHESIS:  
Assuming that the equation for the Doppler frequency shift of a source
moving at constant velocity also applies under dynamically changing
velocity conditions,  one would expect the propagating sound, that is

Hi, All;
Does anyone know the upper resonant frequency limit of either
unimorphs or bimorphs, or both?
Thanks.

Can anyone tell me if reflectivity is a function of acoustical
impedance?  and if so what that function is?  Is there some resource on
the web that address this issue?
Steve M.

I'm looking for acoustic calibration in the net. What equipment is
necesary, what rules, etc
Thanks

I'm looking for an individual or company capable of doing a state of the art
design for an RF Driver capable of driving an acousto optic Q Switch. There are
a few designs on the market, but most are really old designs and we are looking
to manufacture our own device so we can ...

The Mine Safety and Health Administration has finalized it's draft document
on Technically Achievable  and Promising Engineering and Administrative
Noise Controls that are applicable to the mining industry.  It can be
located by going to the MSHA website www.msha.gov and selecting ...

I don't think it does unless one can't linearly transform
the force applied to a piston into sound pressure and I
can't see any reason why not in the linear regime of air.
What do people here know about that?

Could anyone enlighten me as to how the standard resilient channel
performs with impact noise (adding to an existing heavy wall a
resiliently attached gypsum wall)?
An excellent product we know is the  CDM-ISO-T mounting battens: