Spooky Feelings
My hometown of Asheville, North Carolina, is widely considered “the most haunted city in North Carolina.” So rich is our stock of haunted places that the city offers no fewer than five widely advertised ghost tours guiding visitors either by bus or on foot to the dozen or more locations reputed to contain spiritual entities of one sort or another. As tour guides describe various encounters people have reputedly had in these “haunted” places, one of the most frequently mentioned phenomena associated with the experience is a “feeling” the witnesses had—a sudden sense of uneasiness, fear, or sadness that came upon them for no apparent reason. A study recently conducted at MacEwan University in Edmonton, Canada, suggests that, whatever other strange phenomena they may experience, the feeling of uneasiness witnesses describe may not originate from the realm of nature but from below the audible sound.
Not Heard, but Felt
“Infrasound” is a type of low-frequency sound below 20 hertz, which is outside the range of human hearing. Occurring naturally in sources such as tectonic activity and thunderstorms, and also generated by artificial sources such as ventilation systems, low-rumbling pipes, traffic, and various other components of urban life, infrasound has been postulated to induce unpleasant feelings in people when they are exposed to it. Experimental attempts to establish such a connection, however, have been inconclusive; they are based largely on self-reports by participants with no physiological data to draw a correlation. The study at MacEwan University attempted to bridge the gap between subjective experience and objective evidence by “combining verified infrasound exposure with convergent self-report and physiological outcomes.”
Participants in the study listened to either of two audio clips, one calming (an instrumental piece designed for meditation) and one unsettling (a horror-themed ambient audio recording). While listening to these clips, half of the participants were also unknowingly exposed to infrasound from speakers located just outside the testing rooms. Following the experiment, participants completed surveys regarding their emotional reactions to the audio clips. To also test their physiological responses to the clips, the research team took saliva samples from the participants to measure cortisol levels, a hormonal biomarker for stress.
Regardless of the audio clip they listened to—calming or creepy—participants exposed to infrasound described the music as sadder, less interesting, and generally more irritating than participants who listened to the clips without infrasound accompaniment. Significantly, in addition to their reported emotional reactions to the audio, the cortisol levels in the participants exposed to infrasound were measured as higher than those of participants not exposed, indicating higher stress levels in the presence of infrasound.
Infrasound Can Give Us the Creeps
Even though they were not consciously aware of it, exposure to infrasound gave participants an inexplicable feeling of uneasiness, not dissimilar to that described by people in creepy old buildings reputed to be haunted. This finding suggests that the many witnesses cited by ghost tour guides in “haunted» places such as Asheville very likely did feel something in those places; however, it was far more likely to have been aging pipes or an antiquated boiler that they felt than the presence of some spiritual entity.
Ghost aficionados still have plenty of other forms of “evidence” they can cling to (the pinkish glow associated with the famed “Pink Lady” of Asheville’s Grove Park Inn, for instance); when it comes to the ubiquitous uneasy feeling associated with so many haunted places, that’s far more likely a result of physics than it is of spirits. Or, to loosely paraphrase Ebenezer Scrooge from Charles Dickens’ famous ghost story, there’s more of plumbing than the paranormal about most such ghostly encounters.
www.psychologytoday.com
