Health and Medicine
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A new study has investigated the hypothesis that some accounts of hauntings could be explained by the effects of infrasound, finding real physiological and psychological effects when infrasound was present, even when the participants were unaware of it.
The rest of this article is behind a paywall. Please sign in or subscribe to access the full content.Scientists largely tend to stay the hell away from the topic of the paranormal. This is occasionally a shame, as you can sometimes find out some quite interesting things. For example, directly related to the current study, in 1988 a group of scientists working at a laboratory at a medical equipment company began investigating after several strange occurrences. One of the cleaners was the first to spot something odd, and was noticed by one of the scientists – Vic Tandy – as she fled the laboratory.
She claimed that she had seen something, but being scientifically-minded, Tandy put it down to rational explanations, such as a wild animal, lighting issues, or lab equipment. But the strange events kept coming at the lab, which was rumored to be haunted, including to Tandy himself.
Workers at the lab began to feel uncomfortable and even depressed. In one incident, a colleague believed that Tandy was standing by their side, only to turn to talk to him and discover he was on the other side of the room. Tandy was working late one night alone when he began to feel increasingly uncomfortable, and as though somebody was inside the room, watching him.
Tandy knew he was alone, and so began checking the lab equipment for potential leaks, knowing that anaesthetic agents could feasibly cause what he was experiencing. But with no leaks found, he returned to his desk and got back to work. It was here that he saw a gray figure emerge to his left, in the periphery of his vision, and walking as he would expect a person to.
Though terrified and with a strange chill in the room, Tandy turned to look at the silent figure, at which point it disappeared entirely.
The next day, Tandy had another very odd experience, but it led to an explanation for the phenomenon. One of his tasks involved holding a foil blade in a vice. But when he left it unattended and returned to it, he found, to his surprise, that the blade was vibrating wildly in the vice, terrifying him after the events of the previous night.
"However, vibrating pieces of metal were more familiar to him than apparitions, so he decided to experiment. If the foil blade was being vibrated, it was receiving energy which must have been varying in intensity at a rate equal to the resonant frequency of the blade," a report of the case explains. "Energy of the type just described is usually referred to as sound."
Tandy began to move the vice and knife up and down the lab, finding that the vibrations were strongest at the center of the room, and determining that there was a source of infrasound (a low-frequency sound wave below human hearing) within the laboratory. The culprit was soon identified as a new extraction fan, and as soon as it was turned off, the strange occurrences stopped, too.
There are plenty of sources of infrasound out there, and upon investigating it further, researchers of a new study discovered there is some evidence that it may be responsible for other reports of hauntings.
“Consider visiting a supposedly haunted building. Your mood shifts, you feel agitated, but you can't see or hear anything unusual," Prof Rodney Schmaltz of MacEwan University, senior author of the study, said in a statement.
"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. If you were told the building was haunted, you might attribute that agitation to something supernatural. In reality, you may simply have been exposed to infrasound.”
In the new study, the authors recruited 36 participants to listen to music, after which their responses would be measured via questioning, and their cortisol levels would be measured in a saliva test. Half of the participants would listen to regular music, while the other half listened to music laced with infrasound at 18 Hz, which is below the human hearing range.
Reporting on their feelings, the participants who listened to the infrasound version said they were more irritable and less interested in the music, which they reported as being sadder than the non-infrasound participants. Though they could not hear the infrasound and were not consciously aware of it, the team found that the participants' cortisol levels were higher if they listened to the infrasound version.
“This study suggests that the body can respond to infrasound even when we can't consciously hear it,” Schmaltz said. “Participants could not reliably identify whether infrasound was present, and their beliefs about whether it was on had no detectable effect on their cortisol or mood.”
“Increased irritability and higher cortisol are naturally related, because when people feel more irritated or stressed, cortisol tends to rise as part of the body’s normal stress response,” said Kale Scatterty, first author and PhD student at the University of Alberta. “But infrasound exposure had effects on both outcomes that went beyond that natural relationship.”
Whilst increased cortisol levels can help humans by putting us in a vigilant state, prolonged exposure can lead to health and cognitive problems. The new study suggests that while humans may sense infrasound, as their cortisol levels showed, we aren't too great at identifying it.
Though an interesting study, the team wishes to conduct more tests with a larger pool of participants and a wider range of tones, with the team not ruling out other frequencies and combinations of frequencies having their own unique effects.
“The first priority would be testing a wider range of frequencies and exposure durations,” Schmaltz explained.
"Infrasound in real environments is rarely a single clean tone, and we don't yet know how different frequencies or combinations affect mood and physiology. If those patterns become clearer, the findings could eventually inform noise regulations or building design standards."
"As someone who studies pseudoscience and misinformation, what stands out to me is that infrasound produces real, measurable reactions without any visible or audible source. So, the next time something feels inexplicably off in a basement or old building, consider that the cause might be vibrating pipes rather than restless spirits.”
The study is published in Frontiers in Behavioral Neuroscience.
