Natural Science Forum / Physics / Acoustics / October 2007

On May 28, 10:27 pm, Benj <bjac...@iwaynet.net> wrote in
http://groups.google.com/group/sci.energy/msg/17e8728d2165c087 :

Well, I know what the definition is, but I'm trying to understand where it
comes from to help me remember it. I tend to get SPL vs sound power level
mixed up (as well as when it's 3db or 6db that represents a doubling).
The definition I know is:

Problem:
Our house in the city shares a common wall with our neighbor.  At the
back of the house, our dryer vent is positioned about 8 feet from
this

I've just moved into student dorms. It's all nice but turns out that
in my room there is 24/7 noise coming from either glowing-tubes on
corridors and/or ventillation system. It's rather quiet and not
everyone can hear it. I however hear it all the time to an extent that

If I have a speaker with a sensitivity quoted at 102dB (10cm, 1khz), how can
this be scaled to a more useful figure say, at 1 metre?
Thanks
Reg

Is there any accepted objective way to find out whether people will be able
to hear a fire alarm when they are, as part of their job,  listening to
music on headphones (which might be circumaural and/or noise cancelling)?

We currently have one of the quietest ceiling fan models in our bedroom, but
I'm wondering if I can suppress that fan noise even further. However, we
don't want to wear earplugs or noise-cancelling headphones while we sleep.
Just an idea-- Was wondering if it could be possible to ...

I am a college student. I live in an old house with 5 guys. My bedroom
door has a bunch of slats in it, and when people are in the kitchen or
watching TV it sounds like they are in my room. I could buy a new door
for $50, but I wondered what cheaper material could I put up on the

I am looking for information regarding annoyance from maximal noise
levels from airplanes, trains etc. Outdoor Maximal level - occurrence
per day - annoyance? EPA gives LAmax = 80 dB(A). Sweden has LAmax =70
dB(A) as a target, which I think is unrealistic and unnecessary for a

Does anyone have any transmission loss data for thick concrete walls
and/or multi panel concrete walls.
Need to achieve Tl of approx. 42dB @ 63Hz

Refuting Faraday's Law
-- Scientific Concept of the Declaration gave me the strength
I split my mind a long-planned
EMF is cutting