Anyone can capture an EVP with the most basic of equipment. In other blogs I have often recommended using a phone for people who are just starting out. The most common method is using digital recorders which is something else we currently do. However, one thing I haven't discussed is how to get the rock solid, irrefutable, EVPs using more advanced recording equipment. It's not something I talk about too much because it's equipment that the average person or group would not have on hand. However, I have been asked quite a few times how someone would capture the very low range EVPs that happen below the 20Hz range (below the ability of human vocal chords to produce). Unfortunately, we have to use some very specialized equipment to capture and identify those sounds.
Before I get into the specific equipment we use I should mention first that technique is everything. The condenser mics we use are so sensitive that they are actually useless in certain environments. If it's an out door investigation you can forget it. Even with a boom cover the wind noise over the coil is just so loud that you would not be able to pick anything out of the wavform. Also every cricket in a two block radius is going to show up in the recording. That means, indoor only investigations only. At the very least that mic should be located in a closed area without constant drafts. Second, if there are pets or animals in the area you are using this mic; just consider anything you get with it to be circumstantial. There is nothing credible about strange noises on a recording when you cannot account for pets. The best technique is simply going to be setting your equipment up in the center of the area to be investigated, and just leave. No questions, no wandering around, no electronic devices to create interference. Let it record for about two hours or longer without any movement in the area, and no investigators whispering in the background. Make sure all your angles are covered by remote cameras so that you debunk unexpected noises. If you catch something in that period of time, those are the EVPs that you will want to scrutinize.
Okay so what equipment is being used? Basically a simple high sensitivity cardioid condenser mic is what you want. These are the same kinds of microphones that are used by recording studios and on sets during TV recordings. Because of it's construction and quality it can capture noise in a register of below human hearing. This is why it's necessary to have a sound proofed room when recording music and voice during media production. I have used this equipment in the past to record audio for video production and realized after an hour of reading, on playback that I forgot to remove my wrist watch because it could be heard in the recording. The specific Mic I use is an MXL 991. I never run my mics through a wireless receiver, and also I use shielded cables. This eliminates the argument that radio interference could be responsible.
The receiver I use is equipment I have been using for years for just about every kind of audio production. I use a Line6 TonePort digital interface which connects directly to my computer. I can adjust all the levels from the Line6 digital studio software that controls it and I can even filter what ranges the mic will record. In theory I could filter out all noise that happens above the 20kH band to capture only EVPs, but I have learned not to do this. Often when editing video later I like to have all audio present so that I can compare, filter the quality, and help debunk other human made noises captured on alternate devices at other sections of the investigation.
The recording software I currently use is a little newer. I used to use Magix software, but when my favorite version started being incompatible with my computer hardware I decided to shop around. If you have a Windows 7 computer or older Magix Music Studio 10 is very solid software for the price and has many of the same features that my new go to software has. REAPER Digital Audio Workstation is a full suite of programs packed into one digital studio that has everything you need. The best part is it's future compatible through updates, and will not cost you $600.00. The main feature that I like is that when viewing the waveforms within the editor, I can filter the bans. By increasing the volume and filtering down I can actually see EVPs fin the sub 10kH band show up as little blips. With the software I can then isolate the sound and listen at a normal volume. This is a great feature because before I would have to listen for sounds within the white noise of a recording which is a strain on your ears. Also doing analysis that way leaves you prone to auditory pareidolia.
Another method that we employ to get EVPs that are damned near impossible to debunk is the use of a Raudive Diode Receiver in place of a microphone. This can be hooked into the same setup above, or because of the nature of the experiment can be used in conjunction with a simple digital recorder. This is actually not an expensive setup, but far more specialized as you will need a knowledge of electronics to build and test the circuit for proper function.
Latvian psychologist Dr. Konstantin Raudive began his own EVP experiments in the 60's. He would eventually record and study thousands of disembodied voices, creating a system of classification for electronic voice phenomenon in order to rate the quality and clarity of the messages.
During his experiments, he solicited help in building a microphone to enhance his EVP experiments. Using a Germanium Diode as an external microphone, he found he received greater results. More ghost voices were recorded. With the Raudive Diode the recording device will not allow your audio recorder to record human voices, even if people are talking in the same room. This is because the actual device is not actually a microphone but a high sensitivity electronic wave receiver.
A Germanium Diode picks up AM radio frequencies so, when using one to record EVP, it should be placed inside a Faraday Cage. A Faraday Cage is used to block all outside AM radio transmissions from reaching the ghost microphone. Our receiver is mounted within a hard shell Faraday Cage, but one could simply be put into a cloth one instead to save money.
Another method of using the Germanium Diode that's achieved success is to simply attach one to a microphone jack and plug it directly into your digital audio recorder. (If using an older, cassette tape recorder, you will need to use a connecting wire placed between the recorder and diode to keep it away from the motor noise which may cause interference. This set-up makes it easier to incorporate the Faraday Cage.)
When using a digital recorder, you may need to cover the external microphone if it does not disengage automatically. It will depend on your recorder, as the power level of the diode is quite low and may not signal the audio recorder to switch from the internal microphone to an external one. Also, because you might be unable to incorporate a Faraday Cage using this technique, you will need to be wary of radio broadcasts, limiting positive results to only credible phrased answers to questions. One word, irrelevant responses should not be considered. This will reduce the chance of AM radio snippets being mistaken for EVP in your recording.
It's more work than just whipping out your phone and hitting record. But if you have the bankroll, time, and experience, you can capture some truly amazing proof that will actually hold up in a scientific argument.
For an in depth look on building a Raudive circuit, check out the following link: Raudive Circuit