Who you gonna call? Ghostbusters... or maybe the AC mechanic.
Your empirically minded Back Page scrawler does not believe in ghosts.
We are, however, also quite content to accept that occasionally things happen for which we currently have no scientific explanation in this deeply complex and poorly understood universe.
What’s more, we take heart from the fact that cleverer folks than ourselves are consistently coming up with plausible explanations for phenomena that others would choose to attribute to the supernatural.
An example of this would be this recent research by Canadian boffins on the effect of “infrasounds” on human perception, published in the journal Frontiers in Behavioral Neuroscience.
According to the study, infrasounds, which are sound waves emitted at below 20Hz and typically inaudible to the human ear, have the capacity to cause negative feelings and stress for some people.
Exposure to infrasounds could, the research team said, result in higher levels of cortisol in saliva as well as increased irritability, disinterest and sadness. Increased cortisol levels help the body respond to immediate stressors by inducing a state of vigilance.
To establish this link, the team recruited 36 participants and invited them to sit alone in a room while either calming or unsettling music was played.
For half the cohort, hidden subwoofers played infrasound at 18Hz, while the other half only experienced audible frequencies.
After listening, all participants were asked to report their feelings, their emotional rating of the music, and whether they thought the infrasound was present. They also gave saliva samples before the experiment and again 20 minutes after the tests.
The scientists found that participants’ salivary cortisol levels were higher if they had been listening to infrasound and that these participants also reported feeling more irritable and less interested, and thinking the music was sadder. But they couldn’t tell they were listening to infrasound.
Interestingly, some of the most common man-made producers of infrasound are air conditioning units, heavy machinery, aeroplanes and high-speed trains.
“Infrasound is pervasive in everyday environments, appearing near ventilation systems, traffic, and industrial machinery,” study lead author Professor Rodney Schmaltz, of MacEwan University, told media.
The fact that many people might be being unwittingly exposed to infrasound could possibly explain why some feel that buildings and places might be haunted, he added.
“In an old building, there is a good chance that infrasound is present, particularly in basements where aging pipes and ventilation systems produce low-frequency vibrations,” Professor Schmaltz said.
“If you were told the building was haunted, you might attribute that agitation to something supernatural. In reality, you may simply have been exposed to infrasound.”
Of course, the fact that you might feel a little spooked when entering an old building could be caused by some rattling old piping is nowhere near as thrilling as believing it’s the ghostly presence of a falsely accused witch who was hanged centuries ago in Salem, Massachusetts.
Science can be a real wet blanket when it comes to this sort of thing.
Send your ghostbusting story tips to Holly@medicalrepublic.com.au.
