Infrasound, vibrations below human hearing range, triggers measurable stress responses in people without their awareness. Researchers exposed study participants to these ultra-low-frequency waves and documented increased irritability, reduced engagement, and elevated cortisol levels. Participants remained unaware they had experienced anything at all.
The invisible vibrations pervade everyday environments, generated by traffic, machinery, and old buildings. This discovery offers a biological explanation for the "creepy" sensations people report in basements, abandoned structures, and locations considered haunted. Our bodies detect and react to infrasound through mechanisms our conscious minds cannot access.
The findings emerge from a small-scale experiment, but they establish that humans possess physiological sensitivity to frequencies we cannot consciously perceive. Future research will likely explore which structures produce problematic infrasound levels, how exposure duration affects health, and whether protective measures can reduce these effects. Understanding infrasound's role in human experience could reshape how we design buildings and interpret reports of unexplained unease in certain locations.