Infrasound VS Ultrasound

29th June 2021. Reading Time: 11 minutes General, Stuff paranormal investigators need to know. 1455 page views. 1 comments.

Infrasound and Ultrasound are low and high-level sound frequencies that the human ear cannot hear.  Both can also affect a person and what they perceive to be paranormal.

Infrasound and Ultrasound are low and high-level sound frequencies that the human ear cannot hear.  Both can also affect a person and what they perceive to be paranormal.


You will know from my previous posts regarding EVP’s that the human ear can hear sound from 20-20000hz. Infrasound is a sound that is below 20hz. Hz stands for hertz and 1 Hz is the equivalent to 1 vibration per second. Quite a lot of people can hear well below 20hz so to some it may be inaudible and not to others depending on how low the frequency is and what your personal threshold is. It is actually thought some people can hear as low as 12Hz.

Infrasound is a very low-level frequency of sound.  Animals such as Giraffes and Elephants use it to communicate across their large herds over long distances. Before natural disasters, animals seem to flee the area before the disasters hits. It is believed that they are picking up on the infrasound causing them to become fearful and flee. Volcanos emit infrasound when they erupt and meteors also give off infrasound while travelling through space. Infrasound can be detected by a microphone so scientists use it to track animals, monitor volcanos and follow the flight paths of meteors in spaces. 

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Whilst it is a frequency that the human ear may not be hearing, our bodies are certainly feeling it. It is also nicknamed the fear frequency or ghost frequency for this very reason. Scientific testing has shown us that when exposed to infrasound, people have reported feeling anxiety, extreme levels of sorrow, chills, fear, blurry vision, hallucinations and people have spotted what they describe as apparitions. Infrasound itself causes the eyes to vibrate which causes this disturbance in our vision. There is a very famous article ‘The Ghost in the Machine’ published in the Journal for The Society of Physical Research which covers the story of Vic Tandy who worked in a college laboratory. Workers in the lab including Tandy reported paranormal activity.  The lab itself gained a reputation as being haunted. 

The company’s business was in the design of anaesthetic or intensive-care, life
support equipment so there was always some piece of equipment wheezing away in a
corner. When V.T. heard suggestions that the lab was haunted this was the first thing
he thought could be behind it and paid little attention. One morning however none of
the equipment was turned on and V.T. arrived just as the cleaner was leaving
obviously distressed that she had seen something. As a hard nosed engineer V.T. put
it down to the wild cats, wild other furry things, moving pressure hoses (as the
pressure fluctuates, flexible hoses sometimes move) or some sort of lighting effect.
As time went on V.T. noticed one or two other odd events. There was a feeling of
depression, occasionally a cold shiver, and on one occasion a colleague sitting at the
desk turned to say something to V.T. thinking he was by his side. The colleague was
surprised when V.T. was found to be at the other end of the room. There was a
growing level of discomfort but the workers were all busy and paid it little attention.
That is until V.T. was working on his own one night after everyone else had left. As
he sat at the desk writing he began to feel increasingly uncomfortable. He was
sweating but cold and the feeling of depression was noticeable. The cats were moving
around and the groans and creaks from what was now a deserted factory were
"spooky", but there was also something else. It was as though something was in the
room with V.T. There was no way into the lab without walking past the desk where
V.T. was working. He looked around and even checked the gas bottles to be sure there
was not a leak into the room. There were oxygen and carbon dioxide bottles and
occasionally the staff would work with anaesthetic agents, all of which could cause all
sorts of problems if handled inappropriately. All of these checked out fine so V.T.
went to get a cup of coffee and returned to the desk. As he was writing he became
aware that he was being watched, and a figure slowly emerged to his left. It was
indistinct and on the periphery of his vision but it moved as V.T. would expect a
person to. The apparition was grey and made no sound. The hair was standing up on
V.T.’s neck and there was a distinct chill in the room. As V.T. recalls, "It would not
be unreasonable to suggest I was terrified". V.T. was unable to see any detail and
finally built up the courage to turn and face the thing. As he turned the apparition
faded and disappeared. There was absolutely no evidence to support what he had seen
so he decided he must be me cracking up and went home.

The Ghost in the Machine Published in the Journal of the Society for Psychical Research Vol.62, No 851 April 1998

By sheer luck one day, Tandy realised that the foil on a metal blade was vibrating at the same time he felt like he wasn't alone. After lots of investigation and tests, it was found that there was a fan transmitting infrasound at around 19Hz that induced these feelings. When this fan was turned off, all activity stopped completely.

While some could argue that infrasound could be the basis for all paranormal activity, I do not believe this to be the case. We know that infrasound and also EMF have effects on our bodies, but they don't necessarily explain every single paranormal experience. It is important however to be aware of infrasound even just its basics as it can prove to be a very useful debunking tool. Perhaps there is a certain room that people all experience the same thing? Maybe they all feel a sense of dread and see a shadow out of the corner of their eye? Look for anything in the room that could be causing vibrations. What is the source? If you turn off a fan or a fridge for example, does the sensation lift? Can you feel vibrations going through your body? Is there a very low humming noise? These are all signs there could be infrasound at play.

Here is a fun fact .... composers use infrasound frequencies in horror movie soundtracks to help evoke the feeling of dread and pure fear while watching a horror movie! It is even said to be used as a method of torture because of the adverse effect it has on the body.


I am not referring to the medical procedure that you have to have a look at your insides. While this procedure has its name because it uses sound waves, this post has nothing to do with ultrasound from a medical perspective. We are looking purely at the 'sound' component. An ultrasound is a sound that is undetectable by the human ear which is caused by vibration. It is a sound wave that is above the 20000HZ range that the human ear can hear. Think of a dog whistle. It is a high pitched sound that we cannot hear, but a dog can. That is considered to be an ultrasonic frequency.

The whole concept of sound is made up of frequency and vibration. A vibration creates a sound wave. Nearly all objects when hit, struck or somehow disturbed, will create some sort of vibration. You may not hear it with your ear, but it is happening. When an object vibrates, it vibrates at a certain frequency. It is this frequency that determines if you can hear it or not. As we know the human ear can hear frequencies between 20 - 20000hz give or take. Some people can hear more outside this range or less. The older you get, the less you will also tend to hear.

Just rubbing your fingers together can create ultrasound. Any sort of movement can create a vibration either within your body or an object nearby. Research has shown that your computer monitor emits ultrasound and from this, they can actually work out what image is on the screen without looking at it. There is noise around us all the time, but we are not hearing it. The only way to hear it is to use an ultrasonic detector. Companies will use ultrasonic detectors that allow them to hear these high-frequency noises through a device using headphones as it allows them to identify any maintenance issues with equipment. The friction and turbulence of a machine may be emitting a higher frequency noise that we are not hearing. You can also get devices that emit these high-frequency noises to repel a dog. It is called a dog dazer and ironically it is made by K-II enterprises which also manufacturer the safe EMF range device - otherwise known as the K-II meter. 

I have seen various articles and videos which suggest that ultrasound can in fact show up on a digital recording. While it doesn't sound like it at the time to the person in the room, upon playback it does show up as an anomaly. Here is an example I found on YouTube (not my video).

Studies have also suggested that just like infrasound, ultrasound has an effect on the human body.

Many studies confirmed the appearance of subjective symptoms of exposure to noise emitted by
ultrasonic devices like dizziness, balance disturbances, tinnitus and fatigue ...

It is worth mentioning that some subjective effects of exposure to ultrasonic noise such as fatigue, headache, discomfort or irritation may disturb human cognitive functions

Effects of Ultrasonic Noise on the Human Body—A
Bibliographic Review
Bożena Smagowska & Małgorzata Pawlaczyk-Łuszczyńska

On paranormal investigations, people commonly start rocking either in a circle or back and forward, sometimes unaware they are doing it.  They may feel off-balanced or dizzy.  Often they believe it is because they are being affected on a paranormal level.  It could however, be due to an ultrasonic noise they are not hearing at the time.

So here you have two opposite ends of frequency both causing a person to feel things as a result of a sound that they cannot hear.  There are a range of devices that help a person to measure the sound levels so that you can detect if there is any infrasonic or ultrasonic noise around.  If you are a person that is trying to get to the root cause of a haunting, I would argue that these are then an important tool to have in your kit.  In fact, a lot of mobile phones now are capable of running apps to help detect this.  It is also important to remember that even though you cannot hear these sounds with your ear, recording devices can pick them up.  Just because a sound appears on a recording you have taken that you didn't hear with your ear, doesn't mean it is something paranormal.  It could quite simply be an infrasonic or ultrasonic noise.   This is where we could suffer from what is called Auditory Hallucination.

Auditory Hallucinations

It is important to understand that even though the word hallucination is used, it is not a psychiatric disorder. When the brain hears a phantom sound, it tries to make sense of it - much in the same way as pareidolia works. The word pareidolia is defined as a psychological phenomenon involving a stimulus (an image or a sound) where our mind interprets a familiar pattern of something where it doesn’t really exist. If you understand the visual version, basically it is exactly the same, but with sound.  Our brain is constantly looking for patterns so it can make sense of what is happening.  If there is a break or disruption to this pattern, our brain is forced to fill in the blanks.  This is why we will see faces in clouds.  It also means we can often hear things that are not really there.  It also means that when a sound appears on a recording, our brain can make us think we are hearing a voice when it could be a type of infrasound or ultrasound.  

Once you put all of this aside, you also have to wonder how you could use your knowledge of infrasonic and ultrasonic noise to your advantage.  

“If you want to find the secrets of the universe, think in terms of energy, frequency and vibration.” Nikola Tesla

Could playing infrasonic or ultrasonic noise during your paranormal investigation unlock some sort of residual energy or help you connect on some other level?  Perhaps this will be a discussion for part 2 of this topic.

Sound off in the comments below.  Have you had an experience that could be explained by infrasound or ultrasound?  Do you use infrasound or ultrasound to aid your investigations?


The Ghost in the Machine Published in the Journal of the Society for Psychical Research Vol.62, No 851 April 1998

Effects of Ultrasonic Noise on the Human Body—A Bibliographic Review Bożena Smagowska & Małgorzata Pawlaczyk-Łuszczyńska (2013) :

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  • William 2 years ago

    Thank you for yet another interesting and eye-opening article. If only more paranormal investigators out there would be this scientific, I think that it would boost the credibility of the paranormal community in general, which at times seems to be pulled too much in the direction of Zak Bagans and his highly credulous, drama-oriented, ridiculous and irresponsible shenanigans.