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Path: utzoo!mnetor!seismo!columbia!rutgers!clyde!masscomp!ahv
From: ahv@masscomp.UUCP (Tony Verhulst)
Newsgroups: rec.aviation,sci.electronics,rec.audio
Subject: Re: Noise-cancelling microphone
Message-ID: <1746@masscomp.UUCP>
Date: Thu, 21-May-87 09:25:26 EDT
Article-I.D.: masscomp.1746
Posted: Thu May 21 09:25:26 1987
Date-Received: Sat, 23-May-87 13:41:48 EDT
References: <1027@mips.UUCP>
Reply-To: ahv@masscomp.UUCP (Tony Verhulst)
Organization: MASSCOMP - Westford, Ma
Lines: 17
Xref: mnetor rec.aviation:1634 sci.electronics:723 rec.audio:1690


 In article <1027@mips.UUCP> mark@mips.UUCP (Mark G. Johnson) writes:
 >I recently read (in Aviation Week & Space Technology) an article about
 >a noise-cancellation system for military pilots' helmets.  Seems that
 >.....
 >The new system puts a microphone in each earcup, and uses the resulting
 >signal to measure the "error" at the pilot's ear [error == signal at ear
 >minus signal from radio] and thus cancel much of the ambient noise
 >(about 30 dB as I recall).  So the pilot hears the radio but not the
 >loud powerplant.  Pretty cool.
 >

I understand that such a system was used on the Voyager flight and was 
supposed to have prevented the crew from suffering permanent hearing
impairment during their flight.

I don't know if it worked as advertised or if it is commercially available.