Infrasound: The Science Behind Unexplained Fear in Haunted Spaces

If you’ve ever stepped into a haunted house or a location rumored to be haunted and felt an inexplicable sense of dread, science may now have an explanation. According to a study published on Monday, October 2, 2023 in Frontiers in Behavioral Neuroscience, these unsettling sensations could be linked to infrasound—acoustic frequencies below 20 hertz that the human ear cannot detect.

While infrasound is inaudible, prior research has shown that exposure to these low frequencies can provoke negative emotions in humans and animals alike. A team of scientists recently conducted an experiment to explore this phenomenon further, involving 36 volunteers who reported their moods while listening to various musical styles, some of which included infrasound. The participants also provided saliva samples to measure their cortisol levels, which revealed heightened stress responses when exposed to these frequencies.

The findings, published in the study, indicate that “infrasound may be aversive to humans, acting as a potential environmental irritant and contributing to more negative subjective experience.”

How the Study Was Conducted

Kale Scatterty, a PhD student at the Neuroscience and Mental Health Institute at the University of Alberta, led the research. He emphasized the importance of combining psychological and physiological approaches to fully understand the effects of infrasound.

“A lot of the literature seemed to tackle either one side of the conversation or the other, where people are looking at surveys and doing interviews with people, or they're looking into the physiology. We wanted to use this as a first step in combining those approaches to get a whole picture of exactly what was happening with this effect.”

Trevor Hamilton, a professor of psychology at MacEwan University and co-author of the study, highlighted the significance of the cortisol findings.

“It was surprising and exciting to see a significant difference in cortisol when the infrasound was turned on.”

The Link Between Infrasound and Natural Disasters

Infrasound has long been associated with negative effects on humans and animals, though the exact mechanisms remain unclear. Researchers speculate that humans may have evolved an aversion to these frequencies due to their association with dangerous natural events, such as:

• Volcanic eruptions
• Landslides
• Avalanches
• Intense storms
• Stampeding animals

These events produce infrasound, which may serve as an evolutionary warning system for impending disasters.

Infrasound in Human-Made Environments

Beyond natural sources, infrasound is also generated by human activities, including:

• Industrial machinery
• Wind farms
• Air conditioning units
• Busy roads and railways
• Military activity in war zones

This overlap has led scientists to question whether locations perceived as haunted or cursed might be contaminated by infrasound pollution, contributing to the eerie atmospheres reported in such places.

Paranormal Hotspots and Infrasound Research

Rodney Schmaltz, another co-author of the study and a professor of psychology at MacEwan University, incorporates visits to paranormal hotspots into his classes. These excursions provide real-world contexts for studying the psychological and physiological effects of infrasound in environments where unexplained phenomena are often reported.