Overview
- The peer-reviewed study, published Monday in Frontiers in Behavioral Neuroscience, found that brief 18 Hz exposure raised salivary cortisol and increased irritability in 36 volunteers who could not tell the sound was playing.
- In the lab setup, hidden subwoofers emitted infrasound under calming or unsettling music, and saliva samples taken before and after exposure showed higher cortisol alongside reports of feeling more annoyed and less interested.
- Infrasound means very low-frequency sound below 20 Hz that people usually cannot hear, and common sources include ventilation systems, aging pipes, traffic, and machinery that can make old buildings feel eerie without an obvious cause.
- The authors caution the result is preliminary because it used a small, fairly similar group, one frequency, and short exposures, and they are planning broader tests across more frequencies and longer durations along with measurements in reputedly haunted sites.
- The work builds on mixed earlier evidence, including Richard Wiseman’s concert study linking infrasound to more reports of unusual sensations and Vic Tandy’s extractor-fan case, positioning infrasound as a plausible contributor rather than a catch-all explanation.