Sound spotlight

[John Rucker]

Andy,

Check out http://sound.media.mit.edu/~pompei/spotlight/

The concept has been developed at the MIT Media Lab and uses a beam of
directed ultrasound from an array of transducers.  The interaction of the
ultrasound with surfaces and air results in audible difference frequencies
(based on what I can glean from skimming the site).  Seems like pretty cool
tech.

--John

-----Original Message-----
From: Andy Main [mailto:mainas at aston.ac.uk]
Sent: Thursday, January 06, 2000 7:31 AM
To: Synth DIY
Subject: OT: Sound spotlight


Hi all,

I was watching the end of Tommorows World (UK science prog) last night, when
it mentioned that in next weeks show they were going to show a new sound
spotlight.  Now I've been thinking about this ever since, and still can't
work out how the interferance pattern required could be obtained, to give a
true spotlight.

Any ideas? (I generally don't watch TV so I doubt I will ever see it)

Andy