The Big “E”s…EVP (Electronic Voice Phenomenon) and EMF (ElectroMagnetic Field). Arguably, the most discussed evidence. I combine them here since they are related within the subject of the EM Spectrum.
To get to root of the subject, there is no scientific basis behind EVP and EMF having any relationship to the unusual events we seek to explain. Science, as we understand it, tells us any event requires energy to occur. When an event occurs, we should be able to measure the energy associated with the event. Ever since our technology evolved to where our voices could be recorded and played back, there have been efforts to contact those who have died. Similarly, ever since technology could measure the energy associated with motion, there have been efforts to measure the energy of events caused by unseen forces.
Limitations of technology:
Perhaps one of the most important points here is to understand the capabilities of the technology used for our investigations. Read and research the specifications of a particular piece of technology.
EMF meters detect/measure a very narrow range of frequencies. Most are designed to determine if consumer electronics and household wiring are emitting excessive fields that may disrupt the function of other devices or effect people physiologically. None are, nor can they be, designed to detect energy we have not defined. Even custom DIY projects are limited to a narrow bandwidth. Lower frequencies require larger sensors; the simplest of which may be comprised of several miles of wire. Search “antenna theory” for more information.
Audio recorders tend to come in two varieties; one for simple voice dictation and the other for music. The audio bandwidth they will record can be significantly different. Those designed for the human voice may have a narrow bandwidth as part of the effort to eliminate “noise” from the recording. Even the headphones and speakers used to review audio will change what may be overlooked. Be sure to understand the audio bandwidth a given set of headphones or speakers can reproduce accurately. If the bandwidth is unknown or narrower than 20 Hz to 20 kHz, valuable audio information may be lost.
A few links for useful information:
Exceptional articles from Sparc Para Analytics:
More info on EMF:
Skeptic thought on EVP:
Digital Recording Technology: