Surveillance Microphone : Surveillance audio microphone, wired mic or non wired passive mic , and sound amplifier, you can listen to conversations across the street in an open environment. With wired mic, you can use it to listen in on room discussion with the aid of voice recorder. The use of wired microphone can also help in recording GSM or land line phone conversations for evidence gardening between two phone callers voice conversation. Use parabolic dish or sound amplifier to know what hoodlums are saying in your neighborhood for sound security protection. Whom do you want to eavesdrop on with wall contact microphone, wall space contact mic, Gibson parabolic dish, bionic ear microphone, acoustic mic and super ear ? You will not believe what your business partner, spouse or teenagers have for or against you until you try these educational listening devices.