Study: Infrasound Elevates Cortisol, Irritability

A new study from researchers at MacEwan University in Canada has found that brief exposure to infrasound, low-frequency vibrations below 20 hertz that humans cannot consciously hear, elevates stress hormone levels and increases feelings of irritability, offering a potential scientific explanation for unease in supposedly haunted buildings.

The research, published in Frontiers in Behavioral Neuroscience, involved 36 undergraduate students who sat alone in isolated rooms listening to either calming instrumental music or unsettling ambient tracks. Half the participants were unknowingly exposed to 18-hertz infrasound delivered through hidden subwoofers, including units placed in adjacent spaces. Afterward, they completed surveys on their mood and music perceptions and provided saliva samples to measure cortisol, a key stress biomarker.

Participants exposed to infrasound reported higher irritability, discomfort, and disinterest in the music. They also rated it as sadder, regardless of whether it was calming or horror-themed. Cortisol levels rose significantly in these individuals, about 20 minutes post-exposure, compared to the control group. Crucially, participants could not...