Xref: utzoo sci.electronics:7431 sci.math:7622
Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cwjcc!gatech!gitpyr!is813cs
From: is813cs@pyr.gatech.EDU (Cris Simpson)
Newsgroups: sci.electronics,sci.math
Subject: Re: Old Discussion - Noise Reduction
Keywords: white noise, FFT, cancellation
Message-ID: <8997@pyr.gatech.EDU>
Date: 16 Aug 89 21:40:16 GMT
References: <10759@smoke.BRL.MIL>
Reply-To: is813cs@pyr.gatech.edu (Cris Simpson)
Organization: VA Rehab R&D | Ga Inst of Technology
Lines: 32

In article <10759@smoke.BRL.MIL> floyd@smoke.BRL.MIL (Floyd C. Wofford) writes:
>
>TWIMC:
>
>Within the last year there was a lot of traffic on noise
>reduction or noise cancellation techniques in these
>two news groups.  I do not wish to rekindle that discussion,

Fine.   I will.  In the Spring 1989 of "Details on Signal Processing",
a quarterly newsletter published by Texas Instruments, there is an 
article entitled _TMS320, the quietest DSP_ .   The article describes
a system developed by Lotus Engineering and the Institute of Sound and 
Vibration Research of Southampton University.  The system actively 
cancels noise inside the car at the firing frequency of the engine.
A drawing shows 8 microphones and 4 speakers.  

"Engineers at Lotus have used the system in more than a dozen different
types of cars and have measured substantial reductions in the noise    
levels at critical 'boom' speeds, often as much as 10 or 15 dB."

   For more information, TI suggets you call Lotus Engineering in
England at (0953) 608000.  


Thought this might be of interest...  
cris

-- 
||   Gee, do you think it'd help if I plugged in both ends of this cable?   ||
Cris Simpson              Computer Engineer               VA Rehab R&D Center
                        GATech      Atlanta,GA
  is813cs@pyr.gatech.edu           ...!{Almost Anywhere}!gatech!gitpyr!is813cs