Parabolic Microphones and False Positives

Written by Mark Stinson - Ghost Vigil Investigations 

Depending on the model, a parabolic dish amplified microphone can pick up sounds 300-feet away. Whispers 300-feet rubbing together 300-feet away...throat gurgles, stomach growls, foot scrapes, equipment operating, etc. They can also hear sounds through glass. Some models can pick up sounds through thin walls. These are extremely sensitive devices meant to catch and massively amplify sound, and are often sold as a "spy-tool" because they can be used to pick up voices very far away from the person using the microphone.

In the world of affordable powerful microphones, they are among the most powerful. Electronic Voice Phenomenon (EVP) collection is a difficult business, due to how easy it is to create false-positives. The better the microphone, the more sound it picks up.


Powerful microphones will pick up the sound of investigators breathing and swallowing, the sound of stomaches growling in the room, sounds coming from other rooms and outside the building, and other sounds that investigators won't even be aware of at the time the recording is being made. For a more detailed discussion of the topic of EVP collection, please read our Learning Center article on EVP Protocols.

All of the pitfalls that can be attributed to using powerful microphones also apply to parabolic dish amplified microphones. Even more so in some cases.

Troy Taylor states in one of his books that he does not really trust any EVP recorded with human beings present. He once falsely identified an EVP saying "Hello" in response to his own greeting, only to find out later is was one of his investigator's stomach growling. It is very very easy to get false positives when human beings are present. With a parabolic dish amplified microphone, its very very easy to get false positivies when human beings are within 300 feet of the microphone! Possibly even through windows and walls (those these obstructions would reduce the range).

  I went on an investigation with another paranormal group. A week later, they let me know that had collected 27 "EVPs" on the 4-hour investigation. I listened to all of them. One was my voice saying something in response to a question asked over the hand-held radios. Basically, this group used headphones with their radios...and a team leader asked a question over his radio. When I answered over the radio, the extremely powerful microphone this group was using recorded my response, even though the microphone was 10 feet away from the team leader's headphones. No one present at the time of the recording (except the team leader with the headphones) heard my response. But that microphone 10 feet away captured my voice and created an "EVP." And that microphone was nothing compared to a parabolic dish amplified microphone.

When I told the other group that this one "EVP" was actually me talking over headphones, they were extremely mad and told me I was wrong, and "being difficult." I explained that I know what I said during the investigation...and that the "EVP" was definitely me. But any suggestion that their powerful microphone had picked up a voice over headphones over 10 feet away threatened their entire EVP collection process. It was easier to ignore me, than to re-examine their process.

I've noticed that some group only use parabolic microphones outdoors, but some groups use them inside houses, business, basements, and attics. This immediately brings up the following concerns:

  • Are investigators in the room during the recording with this powerful microphone. Humans, their bodies, their breathing, their clothing, and their movement make noises and sounds that can create false-positives.
  • Are there other investigators or the clients in the house at the time audio is being recorded with this powerful microphone. Beside noise causing false positives, living voices captured on the audio are a common false-positive.
  • Are there people outside the house within a block of the house that is being investigated at the time audio is being recorded with this powerful microphone?
  • Are there people in the houses adjacent to the house that is being investigated at the time audio is being recorded with this powerful microphone?

These microphones are so powerful, that I'm unsure its even possible to put protocols in place to prevent someone a block away from getting captured on your audio? I mean other than clearing the block of all people and making sure every radio and television is off in the general area of your target house, what could you do to prevent false positives (in this case the recording of living voices up to 300 feet away) from being captured?

This goes beyond just pareidolia or audio matrixing for that you are sampling so much sound from such a large area, that its difficult if not impossible to eliminate the possibility of recording a living human voice within 300 feet of this thing, even on the other side of glass or walls. In a sense, you are collecting so much audio that you are capturing "garbage audio."


So what are some measures that could be put in place to reduce the amount of garbage audio that is collected? We think these measures may be insufficient, but we are still looking at them: (1) removing all investigators completely from the house, (2) making note at all times of where it is being aimed, (3) securing the microphone on a tripod to make sure it is aimed in a uniform direction at all times, (4) placing other microphones outside the residence to ensure the sounds you pick up are not from outside the house, (5) never aiming it at a window, etc....

Ghost Vigil intends to acquire a parabolic dish amplified microphone, and test it extensively. We're going to perform direct testing of just how many living human voices we can capture from one room away. Two rooms away. Three floors away. The house next door. 5 houses down. And if we can pick up voices from the next block...or the one after that. We would caution anyone attempting to capture EVP's, to avoid using powerful microphones, including parabolic dish amplified microphones.


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