RichD wrote:
A few days ago, I was in a room on the third floor, the
window was open, some people were conversating
down at street level. Their words came in, clear as a
bell, almost like being in the same room. I was surprised,
I thought the power would attenuate a lot faster.
Then I wondered if it also works the other way - could they
hear our conversations, just as crisp?
I recall a discussion of optics, and someone remarked:
'I see you, you see me' is pretty much a universal law.
Does that also hold for acoustics?
Whispering galleries and inside elliptic reflectors, yes. This is the
preferred way to build confessionals in church - at one focus - with
rentable scholarship rooms at the other focus.
Parabolic reflector (satellite dish), not so much. Incoming will be
focused but outgoing will be collimated.
--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/lajos.htm#a2