# Jamming Electronic Bugs **URL:** \ **Category:** Factual Questions\ **Created:** [June 21, 2004, 3:28am UTC](https://boards.straightdope.com/t/jamming-electronic-bugs/251403 "2004-06-21T03:28:06Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![ricksummon](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ricksummon/32/3333_2.png) [@ricksummon](https://boards.straightdope.com/u/ricksummon)\ **Post date:** [June 21, 2004, 3:28am UTC](https://boards.straightdope.com/t/jamming-electronic-bugs/251403/1 "2004-06-21T03:28:06Z")
I’ve heard that there are ways of “jamming” bugging devices so that no one can hear what you’re saying. This doesn’t mean jamming the radio signals. Supposedly, something called “zero-beating” renders sound inaudible to microphones, but not to the human ear. It’s supposed to work even on stuff like shotgun microphones and laser listeners. Is such a thing real? ---
**Author:** ![flight](https://avatars.discourse-cdn.com/v4/letter/f/bbce88/32.png) [@flight](https://boards.straightdope.com/u/flight)\ **Post date:** [June 21, 2004, 3:50am UTC](https://boards.straightdope.com/t/jamming-electronic-bugs/251403/2 "2004-06-21T03:50:44Z")
This is active noise reduction and is utilized to reduce noise at key points. The idea is that you produce a noise signal 180 deg out of phase with the existing noise, and the end result is a VERY limited area of near no noise. The problem is that it only affects a specific location, rather than, say, a whole room, and it affects human hearing as well as listening devices. The ear acts much like a microphone, and anything that affects one will affect the other (unless you start using things like EM generators which whould only affect local listening devices rather than those at a range). You could use this active control to render a known bu location useless, but not any bugs in the area.