Long Range Devices
These devices are used for undected
listening and audio capture from a distance. The most sophisticated of
these employs an apparatus similar to a satellite dish to concentrate sound
waves. This is known as a parabolic mic. The finest of these are capable
of magnifying a signal more than 75 times as much as a regular microphone,
and can cost more than $900 (spooktech.com).
Along a similar vein is the "shotgun"
style microphone, which is a strongly focused microphone that does not
make use of a dish. This allows it to be much more compact and easily concealed.
Shotgun mics are designed to pick up sounds from a set range, and are focused
in on the range of human speech to aid in monitoring of distant voices
Another type of long range sound amplifier
takes the form of a pair of amplifying headphones. These are directed toward
a different purpose. While parabolic mics target specific areas, amplifying
headphones are designed to amplify all sounds, increasing them up
to 95 decibels. These are typically used in very quiet areas, where sensitivity
to all sound is desired (spooktech.com).
Last updated May 14, 1999