A Canadian study published in Frontiers in Behavioral Neuroscience found that an 18 hertz (Hz) infrasound tone raised cortisol and worsened mood without participants’ awareness. In a controlled, blinded study, 36 students sat alone to listen to either calming or unsettling music. Half were exposed to an 18 Hz infrasound signal while the others were not. Those exposed reported heightened irritability, nervousness, and discomfort, and they rated even serene music as sadder, according to The Independent.
Saliva samples showed a measurable jump in cortisol among those exposed, and participants’ expectations failed to account for the physiological and mood changes, according to Deutsche Welle.
A new wave of research is reshaping explanations for “haunted” house experiences, pointing to infrasound as a likely driver of unease, the sensation of a presence, and sudden urges to leave a room. In older buildings, those vibrations can be generated by aging pipes and boilers, rattling ventilation ducts, or creaking heating systems. Outside, passing traffic, storms, or even a steady breeze can feed the same frequencies into a structure.
The waves can travel long distances and pass through walls and floors. Because people typically cannot hear such low tones, their bodies register them as pressure or a subtle force, not as sound, which can tilt mood and focus toward apprehension and be misread as something supernatural in dim light, unfamiliar corridors, or with a story of a restless spirit.
The mechanism may help clarify why certain rooms, corridors, and basements in older buildings feel oppressive or uncanny. When infrasound resonates in a space, people can experience a sense of external pressure, unexplained shortness of breath, or an impulse to move away, even in the absence of obvious noise. Psychologists note that these bodily signals, combined with the brain’s tendency to map ambiguous sensations onto familiar narratives, can be mistaken for a paranormal presence.
Many famous “haunted houses” also share physical features—antique radiators, old plumbing, and ventilation shafts—that are well-suited to generating or channeling low-frequency vibrations. A 2002 concert experiment that mixed an 18 Hz tone into musical performances found a 22% rise in reports of a sinking feeling, vague unease, and other unusual experiences among attendees during the low-frequency segments.
In separate lab setups over the years, volunteers placed in rooms with infrasound and variable electromagnetic fields have reported tingling, pressure, or fleeting apparitions. Work inspired by engineer Vic Tandy’s observation that ~20 Hz vibrations might disturb vision—by resonating with the eye or subtly altering perception—has been echoed by studies using “horror rooms,” where infrasound proved as effective as magnetic pulses at producing odd sensations. Taken together, these strands suggest that minimal, unconscious perturbations—faint hums or field shifts—can be enough to kindle the feeling of not being alone.
Source:
www.jpost.com
