A new study looked at how humans respond to infrasound, a type of sound we cannot hear, inspired by zebrafish research by Kale Scatterty that showed the fish avoided infrasound areas. This suggested infrasound might cause stress. Researchers wanted to see if this was true for people, so they tested if cortisol, a stress hormone, increased with infrasound exposure.
The study involved 36 people who sat in a room while listening to either relaxing or unsettling music. Some were also exposed to infrasound, which was played through hidden speakers. Researchers thought infrasound would make relaxing music more soothing and unsettling music scarier.
However, results showed that all participants felt more irritated and stressed when infrasound was on, no matter the music. Their cortisol levels went up, and they could not tell when they heard the infrasound. This means people can react physically to infrasound even if they don’t know it’s there.
Although this finding is interesting, infrasound alone does not explain why people might feel a place is haunted. Other factors, like our expectations, play a role. While infrasound might contribute to these feelings, it is not the main cause. It might be one part of what makes some buildings feel haunted.
