A recent study suggests that what people often perceive as ghostly encounters may actually be caused by infrasonic vibrations from aging pipes. Infrasound, a very low-frequency sound imperceptible to human ears, can be emitted by old buildings and has been shown to affect mood and increase cortisol levels.
Infrasound and Paranormal Experiences
Researchers from MacEwan University in Edmonton, Alberta, led by Professor Rodney Schmaltz, propose that infrasound could explain many reports of paranormal activity. 'Consider visiting a supposedly haunted building. Your mood shifts, you feel agitated, but you can't see or hear anything unusual,' Schmaltz said. 'In an old building, there is a good chance that infrasound is present, particularly in basements where aging pipes and ventilation systems produce low-frequency vibrations.' He added that if people are told the building is haunted, they might attribute that agitation to something supernatural, when in reality they may simply have been exposed to infrasound.
Survey and Previous Explanations
According to a 2025 survey, over one-third of people in England believe in ghosts and supernatural beings, with 16 per cent reporting personal experiences. Scientists have previously offered explanations such as electrical faults and hallucinations, but this new study focuses on infrasound as a potential cause.
The Study's Methodology
The team enlisted 36 participants who provided saliva samples before sitting alone in a room listening to either calming or unsettling music. For half the participants, hidden subwoofers played infrasound at 18Hz. After listening, participants reported their feelings, the emotional rating of the music, and whether they thought infrasound was playing.
Results and Implications
The results showed that participants exposed to infrasound had higher salivary cortisol levels and reported feeling more irritable and less interested, and perceived the music as sadder. 'Increased irritability and higher cortisol are naturally related,' said first author Kale Scatterty. 'But infrasound exposure had effects on both outcomes that went beyond that natural relationship.' Participants could not tell they were listening to infrasound, and their beliefs about its presence had no detectable effect on their cortisol or mood.
Professor Schmaltz noted, 'This study suggests that the body can respond to infrasound even when we can't consciously hear it.' The researchers now hope to test other frequencies and exposure durations to understand their impact further.
A Historical Perspective: The Cage in Essex
In related news, The Cage in St Osyth, Essex, a former medieval prison, played a role in one of England's most famous witch hunts, in which eight women died. Fourteen women were imprisoned there awaiting trial, including Ursula Kemp, executed in 1582. The building was used as a jail into the early 20th century. One recent owner, Vanessa Mitchell, moved out in 2012 claiming she encountered 12 ghosts, including a shadowy figure over her infant son's cot and a satanic goat captured on CCTV.
