31/10/2025
Happy Halloween! 👻
Do you believe in ghosts? Ever gotten a spooky feeling in an old building?
Those feelings are hard to explain but may actually have a very scientific explanation: infrasound.
Infrasound is sound emitted at a frequency lower than 20 Hz, which is largely inaudible to the human ear. However, it can be created by organ pipes in churches, machinery, and even some natural events such as earthquakes. Some researchers believe that infrasound could induce this “haunted” feeling.
NPL developed an “infrasonic cannon” to test this. It was placed in a concert hall in South London, where 750 people were invited to listen to pieces of contemporary music. Unbeknownst to them, sound from the cannon was intermittently played at 17 Hz. People were then asked to report on their feelings.
The results showed a 22% increase in “odd sensations” experienced by the audience when the sound was played, including sorrow, coldness and shivers down the spine.
So, it could well be that infrasound can induce these spooky feelings. However, it’s difficult to design an experiment to measure subjective experience.
Tag your friends in the comments if they’ve experienced this sensation!
