Path: utzoo!utgpu!watmath!clyde!att!osu-cis!killer!ames!oliveb!sun!pws1!srw
From: srw%pws1@Sun.COM (Scott Wiesner)
Newsgroups: comp.sys.next
Subject: Re: Fwd: LSC problem
Message-ID: <77955@sun.uucp>
Date: 17 Nov 88 00:38:38 GMT
References: <6843@batcomputer.tn.cornell.edu>
Sender: news@sun.uucp
Lines: 18

>>For those who don't know, systems are being developed that
>>can do a Fourier analysis of repeated sounds to find their
>>component sound waves, and then emit a sound composed of the
>>the mirror image of these waves, resulting in destructive
>>interference.  Your ear then hears nothing.  This could be
>>used in an airplane, for instance, so the passengers would
>>hear no engine noise.
>>
> Well, since you're a mathematician you may have an idea of how complicated
> a task this is.  Most people in DSP work I have talked to about this
> idea says, "yeah, sure...show me it happening."  

I'm currently reading the Rutan/Yeager book about their trip
around the world in the Voyager airplane.  One of their problems 
was the noise they had to deal with.  Since excess weight meant
death to them, there was no soundproofing.  They tell of using
a system by Bose that does exactly what is described above.  They
said it worked great.