From: hunter@work.nlm.nih.gov (Larry Hunter)
Newsgroups: rec.audio
Subject: Audio survelliance (was: James Bond microphone wanted)
Date: 6 Apr 92 17:46:37 GMT
	<1992Apr5.192715.16338@bronze.ucs.indiana.edu>
Organization: National Library of Medicine


Paul Walczak writes in response to are request from
mmcguire@Bonnie.ICS.UCI.EDU for technology to help him/her understand
what s/he hears the neighbors saying through their apartment walls.

  Are you serious?  Is your own life that boring?  Do you live
  anywhere near me?  By the way, just a slight detail but isn't it
  also illegal? 

No, it's not illegal.  And no, mmcquire lives in LA and you live in
Indiana (at least judging by your email addresses).  I have no idea
why mmcguire wants to do this, but there is relatively little legal
protection of your privacy, and you should know that.  You do NOT have
a (legally defined) reasonable expectation of privacy in, e.g.
telephone calls made on your portable phone, things your neighbors can
hear through the walls of your apartment, in the medical records your
insurance company keeps, in stuff in the garbage you throw out, or in
any of hundreds of other areas that I personally think you should have
some privacy interest in.  If this bothers you, you should become
informed and take action to improve the situation.  However, I am not
for security by obscurity; I see no harm in teaching mmcquire legal
methods to do what s/he wants to do. Now back to the rec.audio
question (followups on the nonaudio issues to alt.privacy please).

Audio surveillance is an interesting topic for rec.audio....  Probably
the best way to hear through walls is what is known as a spike mic.
Take a guitar pickup or other contact microphone, glue a long, fairly
sharp nail to it, and then mount the spike so that it is pressed
firmly against the wall (rubber bands can help a lot here).  Then run
the output of the mic to a high gain amplifier and headphones
(speakers may feedback, and will certainly alert your neighbors to
what you are doing).  Taping what you listen to may allow you to go
back and decipher something you didn't understand at first.  A
parametric EQ (or even a nonparametric) will help improve
intelligibility.  Try cutting low frequencies and the very high ones.
A high gain amp, a compressor (to even out level fluctuations) and an
eq may allow you to make out what you can hear with a normal or
directional mic pointed at the wall, without the contact mic trick.

For more information on this stuff, I recommend finding Scott French's
book, "The Big Brother Game," or Lee Lapin's "How to Get Anything on
Anybody."  The two of them wrote a book together recently, but I don't
recall the title off hand.  Also, the "Poor Man's James Bond" might be
of interest.

Finally, a bit of advice.  Audio surveillance can be kind of fun, but
remember that invading other people's privacy, legally or otherwise,
is serious business.  Before you go fooling around, think hard about
what would happen if your neighbors found out what you were doing.
Think hard about how you would feel if you found out that someone you
barely knew were doing that to you.  Then decide if you really want to
listen in to your neighbor's conversations.

					Larry
--
Lawrence Hunter, PhD.
National Library of Medicine
Bldg. 38A, MS-54
Bethesda. MD 20894
(301) 496-9300
(301) 496-0673 (fax)
hunter@nlm.nih.gov (internet)