There are people who swear their houses are haunted by ghosts, and there are those who make money claiming to be able to identify the supernatural beings making the noises. According to Rodney Schmaltz, a professor at Canada’s MacEwan University and the senior author of a recent study, your house isn’t haunted by ghosts — it’s haunted by old plumbing. “In an old building, there’s a good chance that infrasound is present, particularly in basements where aging pipes and ventilation systems produce low-frequency vibrations,” he explained. Infrasound is a very low-frequency sound, below 20 hertz, which humans typically can’t hear. Despite it being undetectable to the ear, our bodies respond to the nuisance, which causes higher cortisol levels, the body’s normal stress response. “Infrasound is pervasive in everyday environments, appearing near ventilation systems, traffic and industrial machinery,” Schmaltz said. So, the next time something feels inexplicably off in a basement or old building, consider that the cause might be vibrating pipes rather than restless spirits.
