Silent Vibrations Linked to Ghostly Sensations as Researchers Connect Infrasound to Human Stress Responses

New study reveals how 18 Hz infrasound spikes cortisol and irritability, offering a scientific cause for paranormal experiences in old buildings.

By: AXL Media

Published: Apr 27, 2026, 5:55 AM EDT

Source: Information for this report was sourced from EurekAlert!

The Invisible Trigger for Supernatural Sensations

Scientific inquiry into the unexplained has turned its focus toward the sub-audible frequencies that permeate modern and historical environments. According to Prof Rodney Schmaltz of MacEwan University, the agitation and mood shifts often reported in supposedly haunted locations may stem from infrasound, which is low frequency sound below 20 Hertz. These waves are frequently generated by mundane sources such as aging ventilation systems or vibrating pipes in basements. Because these sounds are undetectable to the human ear, individuals often look for external, sometimes supernatural, explanations for the sudden onset of unease or physical discomfort they experience in these settings.

Probing the Body’s Silent Alarm System

The study utilized a controlled environment where 36 participants were exposed to 18 Hz infrasound via hidden subwoofers while listening to music. This experimental setup allowed researchers to isolate the physiological impact of these low frequency waves from conscious auditory perception. Despite being unable to identify the presence of the sound, those exposed exhibited significantly higher levels of salivary cortisol compared to control groups. This suggests that the human body maintains a sensory bridge to the environment that operates entirely beneath the threshold of conscious awareness, triggering a biological stress response without a visible or audible catalyst.

Quantifying the Emotional Shift of the Unheard

Beyond the hormonal spikes, the psychological data revealed a consistent trend toward negative emotional states. Participants subjected to the 18 Hz tones reported feeling more irritable, less interested, and perceived the background music as sadder than it actually was. Kale Scatterty, a researcher from the University of Alberta, noted that the relationship between infrasound and these outcomes appeared to go beyond a standard stress reaction. The data indicates that the mere presence of these frequencies can skew an individual's appraisal of their surroundings, potentially turning a neutral environment into one that feels inexplicably heavy or mournful.