An Introduction to Frequency


Most investigative effort in the paranormal field is focused on frequency. Whether via “full spectrum” photography, the latest EMF gadget, audio recorders, or DIY sensors and transmitters, the omnipresent trend is to find some paranormal signature within the electromagnetic spectrum. There seems to be, unfortunately, a general misunderstanding of what is being “sensed” with our equipment. As usual, I am not claiming to have to have the one and only correct perspective on this subject. Nor do I intend to provide complete answers and information. I am asking the reader to evaluate any information they are given by taking on a little research of their own.

Whether we see it, hear it, or even feel it, energy as we perceive it, is part of the same spectrum; from static fields to slow (long wave length) approaching zero cycles per second and up to what we can assume is an infinitely fast (short wave length). “Bandwidth” is a range of frequencies within this spectrum associated with a specific topic. We are most familiar with bandwidths such as visual, audio, radio, infrared, ultraviolet, etc.

Electromagnetic Spectrum as we understand it:

Frequency – Cycles per second / hertz (Hz)

Cycles per Second 10 ^ X Nomenclature example
0 to 999 10^0 Hz (hertz) Ultrasound, Audio, Brainwaves, household power
1,000 to 999,999 1*10^3 to 999.999*10^3 kHz (kilohertz) Audio, AM Radio
1,000,000 to 999,999,999 1*10^6 to 999.999…*10^6 MHz (megahertz) Shortwave Radio, Television, FM Radio
1,000,000,000 to 999,999,999,999 1*10^9 to 999.999…*10^9 GHz (gigahertz) Microwaves, Radar, Radio Telemetry
1,000,000,000,000 to 999,999,999,999,999 1*10^12 to 999.999…*10^12 THz (terahertz) Infrasound, Infrared, visible light
1,000,000,000,000,000 to 999,999,999,999,999,999 1*10^15 to 999.999…*10^15 PHz (petahertz) Ultraviolet, X-Ray
1,000,000,000,000,000,000 to 999,999,999,999,999,999,999 1*10^18 to 999.999…*10^18 EHz (exahertz) Gamma rays

graphic from:

Static fields (those with essentially no measurable frequency) include; magnetics, batteries, and the potential charge that zaps our fingers when we reach for a door handle. An intriguing, yet seldom discussed, aspect of the EM Spectrum is brain waves; near 0 Hz up to about 60 Hz. Within this frequency range, we also find information covering the Schumann Resonance (frequencies associated with Earth’s magnetic field). I will not go into this sort of detail here but, I recommend anyone intrigued by paranormal events also look into frequencies of the brain and the Schumann Resonance. There are many different definitions but an introduction is shown below.

Brain Frequencies and Schumann Resonance Peaks

Frequency Bandwidth Brainwave Name Associated with: Schumman Peaks
>35 Hz Gamma Panic, Fear, Loss of Reasoning 39 Hz
24-35 Hz Beta 3 High Alert Activity, Flight or Fight 26 Hz & 33 Hz
15-24 Hz Beta 2 Active Consciousness, Sleeplessness 21 Hz
12-15 Hz Beta 1 Conscious but Relaxed Attention 14 Hz
7-12 Hz Alpha Relaxed, Eyes Closed, Pre & Post Sleep 7.8 Hz
4-7 Hz Theta Dreams, Deep Meditation, Hypnogogic, REM Sleep, and certain creative states
<4 Hz Delta Deep Sleep

At 50 and 60Hz we find the most common frequency for household power. 20 Hz up to 20,000 Hz (20 kHz) is the nominal frequency range for human hearing. Above 20 kHz we find defined bandwidths like radio, microwave, infrared, visual, ultraviolet, x-ray, gamma, etc…

The “man-made frequency” misnomer:

Nature vibrates, typically with a sinusoidal wave shape. The EM spectrum is not man-made, it is entirely comprised of natural frequencies. Man has found ways to utilize and manipulate certain frequencies into signals to enable technology. Our technology generally creates signal shapes other than sinusoidal and signal patterns intended to transfer information. There are no uniquely man-made frequencies, though signal patterns are often man-made. While determining the frequency of an EMF “spike” may ultimately be valuable in attempting to determine its origin, the frequency alone does not indicate a man-made origin.

Limitations of technology:

Perhaps one of the most important points here is to understand the capabilities of the technology used for paranormal investigation. 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 paranormal energy. 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.

A “full spectrum” camera is not capturing a full spectrum image and the associated LED illuminators often utilized are further limiting what the camera might potentially capture. With respect to the visual bandwidth, standard cameras are already “full spectrum”. The specifications of the sensor in the camera will indicate sensitivity to frequencies beyond that of human vision. Filters are added to the light path in the camera to block infrared and ultraviolet along with software interpretation of the data from the sensor to result in an image our eyes and brains recognize. What is marketed as “full spectrum” simply has the IR and UV filters removed. This allows a wider bandwidth of frequencies to reach the camera sensor. The software interpreting the data is not adapted to the IR and UV data so the resulting image is already subject to produce a false interpretation. Increasing the discrepancy, we tend to use LED illuminators. LEDs emit a very specific frequency. If whatever we are trying to enhance is at a different frequency, the LED illuminator may be washing out the image preventing capture of the desired image. Also, without understanding the specifications of the camera sensor, the illuminator we choose may not emit a frequency the camera can sense properly regardless of the intensity of the LEDs. Be sure to understand the light wavelength/frequency the given camera and illuminator are designed for. There are alternate non-LED illuminators but these come with heat/fire risks from IR lamps and potential eye and skin damage from UV lamps. True IR and UV image systems are also available but come at significant cost.

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 typical specifications; research your equipment to understand its limitations.

Typical unfiltered camera sensor sensitivity: 303 THz to 999 THz

Typical Infrared LED emission: 316 THz to 353 THz

Typical Ultraviolet LED emission: 749 THz to 821 THz

Typical low cost microphone dynamic range: 60 Hz to 12 kHz

Typical low cost headphone dynamic range: 60 Hz to 16 kHz

Typical low cost voice recorder: 100 Hz to 10 kHz (usually dependent on optional settings)


Additional info, Aspects of physiology:

human – vision: 400 to 790 THz, hearing: 20 Hz to 20 kHz

canine – vision: 484 to 697 THz, hearing: 60 Hz to 45 kHz

feline – vision: 500 to 700 THz, hearing: 20 Hz to 64 kHz

This does not mean humans and their common pets see colors in the same manner.   Studies suggest what humans see as red, orange, and yellow may be more blue or gray to many animals. Additionally, many animals have an extra structure in their eyes allowing them a level of “night vision”.

An important aspect, not to be detailed here, is temporal resolution. Temporal resolution is a measurement of at what rate a series of images appears to be continuous motion. Television images flicker at about 60Hz allowing us to perceive the sequence of images as continuous motion. Dogs and cats have higher temporal resolution, meaning they do not see continuous motion on the television screen but can see a series of images.

As far as hearing goes, dogs hear higher frequencies than human and cats can hear even higher frequencies. There are many aspects of perceptual differences between species. Since this is beyond the intent of this discussion, I suggest the reader research these details further. When your cat or dog stares off into a direction where there is nothing to see, it is likely they are listening to a frequency we cannot hear rather than actually looking at something.

With all species, there is a tendency for our visual and audio senses to weaken with age or other damage. Many frequencies can damage the structures of our body as well cause significant changes in how our brain functions.

Search the internet for additional images showing the electromagnetic spectrum. Such as:

Much of the information will be formatted as wavelength and/or energy. This link is for a conversion calculator for wavelength/frequency/energy:

Rob Hillstrom

Rob Hillstrom

Director / Chair Science at TEPI
Paranormal: Somewhat cliché but, my experiences began at a young age though I don’t recall making the “paranormal” association until the age of 9 when my grandmother died and returned for a visit. Through the years, I have given many phenomena more attention; from subtle dream images to apparent physical contact from “unseen” sources. I have been involved in independent research/study and investigation for about 30 years and began using some equipment about 20 years ago. I have been working with the Colorado based TEPI team since 2010. As a science oriented investigator, I am a bit of a contradiction. I believe the experience more so than the evidence. Simply because there can be many plausible explanations for most evidence. The experience on the other hand, can sometimes be very complex and difficult to explain easily. Professional: I have a Master of Science degree that essentially qualifies me to manage a multi-discipline team in their efforts to accomplish technical activities. (If I say more the MIB might show up.) My engineering background is primarily electronics but includes mechanical, astrophysics, and some aspects of thermal, optical, and audio. Previous careers were medical including paramedics and medical device technology (design, manufacturing, and training medical staff). I also dabbled heavily in photography before the wide spread use of digital imaging. Ideological: I was raised Presbyterian but allowed to find my own path. I studied Zen for a short time and explored many other faiths. In my late teens I attended a seminar on the subject of Quantum Physics and how it relates to our mind and consciousness; this was the turning point in my belief system. I did not become a scientific skeptic, I simply began to view nearly everything differently. I removed definitions I had learned and replaced them with relationships to my personal experiences and observations. Things once clearly defined as paranormal now had a plausible spin to them. Personal: In my spare time I write dark music, dark poetry, and horror/science fiction stories.
Rob Hillstrom

Latest posts by Rob Hillstrom (see all)