Testing the Body’s Stress Response
A recent conversation with neuroscientist Kale Scatterty sparked a new study focusing on stress responses. Scatterty had previously co-authored a paper showing that zebrafish exhibited an anxiety response to infrasound, leading them to avoid certain areas in their tanks. This finding raised the question for Schmaltz about whether similar physiological reactions occur in humans. To investigate, they designed a lab experiment to see if exposure to infrasound would increase cortisol levels in participants’ saliva, a known indicator of stress.
In the study, thirty-six participants were placed alone in a room, exposed to either soothing music typical of a yoga class or more disconcerting ambient sounds, with half of them also subjected to infrasound from hidden subwoofers. Initially, Schmaltz theorized that those experiencing infrasound would find the calming music even more comforting, while the unsettling tunes would be perceived as more disturbing.
Contrary to those expectations, the findings revealed that participants felt increasingly irritated and uneasy when the infrasound was active, regardless of the music type. Their cortisol levels rose notably, and interestingly, none of the participants could accurately sense when infrasound was present. This indicates that humans may react physiologically to infrasound, even if we’re not consciously aware of it.
Although these results are intriguing, it’s unlikely that infrasound is the only factor affecting our experiences with hauntings. Other elements likely play a role, such as earlier findings on suggestibility by Wiseman. Schmaltz clarified, “Infrasound isn’t necessarily ‘causing’ hauntings. We’re not claiming to have solved the mystery of hauntings. But in older buildings, low rumblings from pipes might be generating infrasound, and if someone expects something eerie to occur, that sound could amplify those feelings. So, while infrasound doesn’t account for everything, it might be a contributing factor in some haunting experiences.”
