Natural Science Forum / Physics / Acoustics / December 2007

What is standard equipment to measure low frequency sound?
Lots of papers about the subject of LF annoyance, but I can't find how
they measure it.
Thanks in advance!

I know that two sinusoidal waves can produce beats if their
frequencies are nearly similar.
I have a question: can I feel the same effect also with two complex
signals in place of two sinusoidal waves?

    Over the past year+, I have been performing reviews of patents for the
Journal of Te Acousticla Society of America (JASA). There are about a
dozen of us that do this plus an editor and assistant. My selected
specialties are ANC and SAW devices.  These reviews are sometimes time

what canwe do about this MI5 persecution .......?
we can't talk about acoustics

A young friend has expressed continual interest in the resonances of
different materials, including harmonics of same materials when they are
struck.
I have no idea what this science would be called for him to start learning -

I'm new to acoustics in general but I have this instrument which
involves lightly scraping the end of aluminum pipes off porcelain
glazed tiles (a sort of glassy surface). One tile is on the ground and
the other is lifted slightly off the ground for a different timre. I

If you have the patience to listen he says he was playing with
sympathetic vibration and made a ping pong ball float above a speaker
at 28 000 cycles. Back at work they shredded his documentation and
instructed him to go back to "researching" electromagnetic levitation,