Re: domestic audio surveillance in LA, Redwood City

[David Honig <honig@sprynet.com>]

At 07:01 AM 1/7/00 -0600, Dean, James L wrote:
>Could the telephone mounted mikes be used as
>a giant phased array to pinpoint conversations?

(from what I gathered from shotspotter.com) 
They're not set up for this; they just use
timing and intensity information to 'triangulate'.

The manufacturer claims the mics, placed on utility poles, are not
sensitive enough to pick up conversation
on the street.  One imagines that is not fixed in stone.

After a 'shot' is heard the system relays 8 seconds of
sound to the police; this lets them discriminate between
firecrackers, backfiring cars, and drive bys.  So the
mics *do* capture ambient sound like an ordinary mic.

One could easily make them more sensitive to sounds from
a certain direction, say, the street, or the outdoor
tables frequented by execs who discuss business plans
at lunch.. Cone of silence, anyone?