A team of researchers from MacEwan University in Edmonton, Alberta, has uncovered a scientific explanation for the eerie feelings often associated with haunted houses. Their study suggests that infrasound, sound waves at frequencies too low for human hearing, can influence emotional states, potentially creating a sensation of being haunted.
Study Design and Findings
Led by Dr. Rodney Schmaltz, a professor in the Department of Psychology, the research involved 36 participants who sat alone in a room while listening to either relaxing or spooky music. Half of the participants were also exposed to infrasound at 18 Hertz, below the human hearing threshold of 20 Hertz, emitted by hidden subwoofers.
After the session, participants reported their feelings, rated the emotional tone of the music, and guessed whether infrasound was present. Saliva samples were collected before and after to measure cortisol levels, a biomarker for stress.
Key Results
The researchers found that those exposed to infrasound reported higher irritation, lower interest, and rated the music as sadder compared to those without infrasound. Cortisol levels were also elevated in the infrasound group. Notably, participants could not reliably detect the presence of infrasound.
Dr. Schmaltz noted that detecting infrasound typically requires specialized equipment, but a simple test using a lighter or match can reveal its presence if the flame bends without a breeze.
Implications for Haunted Locations
The study references previous research, including a 1998 paper titled “The Ghost in the Machine,” which suggested that 19 Hz standing waves could create ghost-like sensations. Infrasound is also generated naturally by tectonic activity, storms, and human-made sources like ventilation systems, air conditioning, and traffic.
These findings offer a rational explanation for haunted feelings, linking them to environmental infrasound rather than paranormal activity.
