Arthur C. Clarke once said that any sufficiently advanced technology is indistinguishable from magic. Does plumbing count? It should, at least according to new research suggesting that many “ghostly” experiences in haunted houses may come down to something as mundane as rumbling old pipes.

A recent experiment detailed in Frontiers in Behavioral Neuroscience points are suggesting that the ghostly creeks and moans you might hear when exploring a spooky dilapidated building that is supposedly haunted are really just infrasound, aka sound waves below 20 Hz, which are beyond the range of human hearing. That leads to an obvious follow-up question: if it’s beyond the range of what our ears can detect, how are we hearing them well enough to be spooked into thinking that they were the sounds of spectral apparitions?

Your ears don’t pick them up, but the rest of your body is definitely picking up the vibe they give off, like you’re a big tuning fork. The vibrations can be produced by old plumbing, creaky boilers, dusty ventilation systems, nearby traffic, or even just a passing breeze. When your body gets hit with a wave of these bad vibes, it can immediately detect them and, if you’re so inclined, interpret them as phantasmal rather than what they actually are: old infrastructure in desperate need of maintenance.

Scientists Found a Boring Explanation for Why Haunted Houses Feel Haunted

Researchers exposed volunteers to both calming and unsettling music, sometimes layering in infrasound through hidden speakers. The participants couldn’t hear the infrasound with their ears, but their bodily signals suggested they were detecting it nonetheless. Cortisol has become a bit of a buzzword nowadays, so you likely already know that it’s the hormone tied to stress. The researchers found that cortisol levels rose significantly, and people reported feeling more irritated and on edge as soon as the infrasounds began. Even those listening to calm, serene music began to feel overwhelmed by a vague sense of ominousness.

Knowing that, imagine yourself walking through a supposedly haunted house. A deep sense of unease looms over you, and you’re not quite sure why, but your brain is definitely filling in the absence of information with as much spookiness as it can generate. Rodney Schmaltz, the study’s co-author, said in a statement that people are misattributing these feelings to the spiritual when the real answer is in a combination of sound waves and our brains pulling a Fox Mulder because they want to believe. If you believe a place is haunted, the low-grade, ominous stress provided by infrasounds will be interpreted as evidence of the supernatural, when it’s really just some sh—y pipes.

These findings aren’t necessarily new, but they do support some findings from a pair of studies dating back just over 20 years, as noted by Ars Technica. Researchers found that supposedly haunted locations like Hampton Court Palace in Surrey, England, left people feeling as if they were among otherworldly spirits, but their experiences were actually strongly correlated with environmental factors such as lighting, magnetic fields, and humidity. Basically, the same stuff that makes a Hollywood set designer good at their job. People were reacting to literal spirits, but common real-world physical sensations.

The research doesn’t provide explanations for other hallmarks of the haunted house experience, such as moving objects or the sighting of full-bodied apparitions. But the researchers did find patterns consistent enough to suggest that what people are interpreting as the work of ghosts is really just the subtle hum of aging toilet pipes.