Ghosts: New Study Reveals Unexpected Insights

If you’ve ever experienced a sensation of being watched by something beyond our reality, rest assured that you are not alone in this feeling. Recent research, however, might provide a more ordinary yet still deeply unsettling explanation for some of these encounters with the supernatural. The study suggests that certain environmental factors could contribute to these eerie sensations that many people attribute to ghostly presences.

In a groundbreaking experiment conducted by scientists in Canada, volunteers were exposed to low-frequency sounds, known as infrasound, which are typically inaudible to the human ear. When compared to control subjects, those exposed to infrasound reported elevated feelings of irritability and exhibited increased levels of cortisol, a hormone associated with stress. The findings indicate that hidden sources of infrasound may trigger the unsettling feelings often linked to locations reputed to be haunted, according to the researchers involved in the study.

“It is crucial to clarify that infrasound does not induce beliefs of having witnessed a ghost. Rather, it may create inexplicable discomfort, which some individuals could interpret as evidence of a haunting,” explained Rodney Schmaltz, the senior study author and psychology professor at MacEwan University, in an interview with Gizmodo.

Could Infrasound Be the Explanation Behind Haunting Experiences?

A YouGov poll conducted last October, conveniently around Halloween, revealed that a significant 60% of Americans believe they have experienced at least one paranormal event in their lifetimes. Among these experiences, the most frequently reported sensation, at 35%, was the eerie feeling of “perceiving a presence or unfamiliar energy.”

Many of the narratives behind the most notorious ghost sightings lack credibility. Moreover, some individuals’ paranormal encounters may simply reflect how susceptible our minds are to the mere suggestion that an old house or shadowy basement could harbor restless spirits. However, certain locations worldwide consistently evoke feelings of unease, leading some scientists to explore answers grounded in reality, including the role of infrasound.

Infrasound is characterized as sound with a frequency at or below 20 hertz. Although humans typically cannot perceive these low frequencies, higher-intensity infrasound can still be felt physically as vibrations or pressure changes. Individuals often report feelings of discomfort in the presence of infrasound, prompting some researchers to investigate its potential role in explaining haunting phenomena, although findings have been mixed.

Schmaltz and his research team previously studied the effects of infrasound in notable locations known for their spooky reputations. This time, they designed a controlled laboratory experiment involving 36 participants. Each volunteer was instructed to sit in a room while listening to either calming or unsettling music. Half of the participants were subjected to infrasound (18 hertz) emitted by hidden subwoofers. Their cortisol levels were measured through saliva samples before and after the session, and they were surveyed regarding their mood. After the experiment, they were asked if they believed they had been exposed to infrasound during their session.

Overall, those who listened to infrasound reported feeling more irritated and less engaged on average during and after the music session compared to those who did not hear infrasound, and their salivary cortisol levels increased significantly. Additionally, participants tended to describe the music played during the experiment as sadder.

“An important detail to note is that the results did not depend on whether participants believed that infrasound was present. When we asked them at the end of the session if they thought they had been exposed, their responses were no more accurate than random guessing, and their beliefs did not influence their mood or cortisol levels,” Schmaltz stated. “Thus, the observed effects were not a result of conscious awareness of the stimulus and subsequent reaction.”

The findings from this study were published on Monday in the journal Frontiers in Behavioral Neuroscience.

What Are the Implications of This Research?

The researchers acknowledge that the sample size for this study is relatively small, though the results remained consistent across various sensitivity analyses, which are designed to assess the reliability of a study’s findings.

Simultaneously, other research has corroborated the notion that infrasound can heighten our sense of creepiness. In 2002, for example, a well-known study conducted by psychologist Richard Wiseman and colleagues exposed hundreds of concertgoers in London to inaudible notes of infrasound embedded within particular songs. Following this exposure, participants were 22% more likely to report “unusual experiences,” such as a sensation of unease during the songs that included infrasound.

The researchers view their work as a foundational step toward understanding how infrasound influences the human body, even beyond the context of reputedly haunted locations.

Low-frequency sounds are prevalent in many everyday environments. Sources such as ventilation systems, furnaces, heavy traffic, large appliances, and industrial machinery can all generate these sounds,” Schmaltz remarked. “If even modest exposure to infrasound can negatively impact our mood and elevate cortisol levels without individuals realizing it, this has significant implications for any environment where these sound sources are present over extended periods.”

The research team aspires to conduct larger and more intricate studies that can more accurately delineate the physiological effects of infrasound. This may involve exposing participants to a broader range of low-frequency sounds for longer durations, more representative of real-world sound sources. They are already working on a new study aimed at determining whether well-known haunted locations exhibit higher levels of background infrasound compared to similar buildings that are not considered haunted.

In the meantime, some individuals might find comfort in the notion that their previous encounters with the supernatural were neither purely paranormal nor entirely a product of their imagination.

“None of this negates other explanations for reported hauntings. Expectation and misperception play significant roles in why someone might claim to have experienced a haunting. Nevertheless, infrasound may serve as an additional factor in the overall equation,” Schmaltz outlined. “For individuals already predisposed to interpret strange sensations as evidence of a presence, infrasound could be enough to sway an ambiguous moment toward a ghostly interpretation.”