Sometimes you get the same feeling walking down empty streets at night, as if someone is right behind you…
You may try to reassure yourself, “Don’t be silly, there’s nothing here,” yet that uncomfortable feeling just won’t go away.
Recently, scientists have offered a rather unexpected explanation. This is not just your imagination. There is a type of sound that is completely inaudible to your ears, yet it truly exists.
A research team from McMaster University and the University of Alberta in Canada published an experiment in the journal Frontiers in Behavioral Neuroscience.
They recruited 36 volunteers and split them into two groups, each sitting in a separate room listening to calm, relaxing music.
In one room, they secretly placed a subwoofer continuously playing infrasound at 18 hertz. The other room had no such sound.What does 18 Hz mean?
The lowest frequency audible to the human ear is approximately 20 Hz. 18 Hz falls just below this threshold. It cannot be heard by human ears, yet the body constantly perceives it.
The results showed that volunteers exposed to 18 Hz infrasound had significantly higher cortisol levels in their saliva. They were more likely to feel irritable and anxious, and they tended to perceive the music as sadder than it was.
Most strangely of all, they had no idea they were being affected by sound. When asked if there were any extra noises in the room, they insisted there were none.
So where does this infrasound come from?
Take old houses for example: airflow through aging doors and windows, ventilation ducts, walls, or roof tiles can all produce it.
You cannot hear these sounds with your ears, but your body is detecting them—and your adrenal glands are working overtime.
I have met many people who were thought to be “demonically possessed.” They often experienced medical symptoms of auditory hallucinations: constant voices or strange sounds in their ears.
This may not actually be demonic possession. Instead, they might have some form of auditory disorder that allows them to hear sounds most people cannot.
For instance, cats, dogs, and many other animals can hear frequencies beyond human range.
Those with stronger mental resilience can cope, but those who are more vulnerable may gradually lose their minds over time.
Therefore, people with auditory hallucinations may not necessarily have mental or psychological issues. Their hearing itself could be abnormal, and treatment should perhaps focus on the auditory system.
I know someone who is now nearly retirement age. She began having auditory hallucinations at a young age. For decades, every time she lies in bed at night, she hears voices speaking to her.
She never married, nor had children, and has lived alone.
I treated her before. Each treatment would relieve her symptoms for a while, but they would return over time.
Fortunately, she has strong mental endurance. She has grown used to it and does not let it bother her. She still works and lives normally. She never talks about it to others, so no one knows.
This is just one case, of course. We cannot rule out the possibility that a small number of people are truly experiencing demonic possession. As for the scientific explanation behind such phenomena, I believe answers will be found in the near future.
