Low-frequency sound has also been investigated by the military as a possible basis for acoustic weaponry, and is informally referred to as the dreaded “brown note” because it can allegedly vibrate people’s bowels, causing them to defecate. Although sound engineers have known about this possibility for years, in 2000 the concept entered the public domain when an episode of the cartoon
South Park
depicted one of its child characters inadvertently broadcasting the note on the radio, causing the entire nation simultaneously to empty their bowels. Because of the resulting coverage, the science show
Myth Busters
tested the concept by subjecting people to high levels of infrasound. Although the presenters reported feeling nauseous, the study failed to produce the much-rumored effect.
There was, however, one problem. Most of the military and industrial investigations had used very high levels of infrasound, whereas Vic was speculating that much lower levels might be enough to induce a weird ghostly experience or two. It was time for an experiment.
A SMALL DRAFT, OR A COST-EFFECTIVE WAY OF FINDING GOD
Sarah Angliss, a long-time friend of mine, studies acoustics and produces sound installations for museums and other public spaces. One evening we were chatting about ghosts and Vic’s low-frequency sound hypothesis. Sarah was also interested in infrasound and suggested that we team up and conduct an experiment. We needed an event that would attract large numbers of people, and one in which they could rate how they felt while infrasound was either present or absent. Sarah had the idea of piping infrasound into certain pieces being played at a live concert to discover whether the secret sound wave affected the way in which the audience felt about the music. Could it, for example, induce the types of strange experiences often associated with the presence of a ghost, such as a sense of being watched, sudden feelings of cold, and a tingling on the back of the neck?
Sarah led the crack squad of engineers and physicists who built a high-tech infrasound wave generator that allowed us to produce infrasound at will. In reality, this was a seven-meter-long sewage pipe equipped with a low-frequency speaker in the middle. Sarah was present when the system was first turned on: “The pipe began to resonate strip lights, furniture and other objects. As the pipe made very little audible noise, this was an odd experience. Seeing objects vibrate for no apparent reason, it is easy to imagine how infrasonic energy could be mistaken for a ghostly sighting.”
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Teaming up with my PhD student at the time, Ciarán O’Keeffe, and two National Physical Laboratory acousticians, Richard Lord and Dan Simmon, we hired one of the main concert rooms on London’s South Bank and staged two unusual concerts. Each concert would consist of various pieces of contemporary piano music, performed by the acclaimed Russian pianist GéNIA. At four points during the concert, the audience would be asked to complete a questionnaire that measured emotional responses to the music and to note any unusual experiences, such as tingling sensations or suddenly feeling cold. Just before two of these points, the auditorium would be flooded with infrasound.
The two concerts would be identical, except for the timing of the infrasound. If the generator was turned on in one piece in the first show, it would be turned off in that piece in the second show. This counterbalancing procedure would enable us to minimize other sources of emotional effects, such as differences between the pieces of music. We would also be careful to produce a level of infrasound that was on the cusp of perception and this, coupled with the fact that it was masked by GéNIA’s music, would help ensure that members of the audience were never consciously aware of its presence.
Staging the concert was far from easy. The South Bank concert rooms were not far from the London Zoo, and there was an initial concern that some of the animals might be affected by the infrasound, thus re-creating the “unusual uproar” initiated by Galton’s sound studies over a century before. A few “back of the envelope” calculations revealed that our four-legged friends at the zoo had nothing to worry about. However, the same calculations also showed that if we were not careful, the humans in the hall did. High levels of infrasound can cause unpleasant effects on people’s bodies; naturally, we wanted to expose the audience only to levels that were safe. The potential problem was that as the infrasound bounced around the hall, there would possibly be areas of the auditorium where the waves added together to create an unusually loud, and potentially dangerous, effect. To prevent this happening, it was important to turn on the pipe before the concert, and then to have Richard and Dan carefully sweep through the auditorium checking the infrasound levels.
The team assembled on the morning of the concerts, the pipe was installed at the back of the hall and turned on to maximum power, and the sweep began. Thankfully, the results revealed that no parts of the hall were exposed to dangerously high levels of infrasound. Relieved, we continued with our preparations.
My role was to be master of ceremonies. To welcome people, explain the purpose of the experiment, and ensure that the questionnaires were properly completed. Ciarán had decided which pieces of music would include the infrasound and so sat with Richard and Dan as they controlled the pipe. Sarah was team leader, and also presented a talk after the concert explaining the science underpinning the event. GéNIA played each of the pieces during the concert.
Conducting these types of live events is always nerve-wracking. There can usually be only one chance to get everything right and, if anything does go wrong, there is a high potential for public humiliation. Good publicity had ensured that the event was a sell-out, and GéNIA and I waited nervously backstage as two hundred members of the public filed into the hall for the first concert. The lights in the auditorium slowly dimmed, and I walked onto the stage and welcomed people to the unique event. GéNIA played each of the pieces perfectly, the pipe was turned on and off on cue, and the audience had a thoroughly enjoyable time. Everyone completed the questionnaires at the end of the four experimental pieces of music and handed them to us as they left the hall. I needn’t have been nervous. The whole concert ran like clockwork. About an hour later, we repeated the entire process for the two hundred people attending the second concert, and then we retired to the nearest bar.
The following week, my research assistant entered the questionnaire data into a computer and analyzed the results. Had all of Sarah’s careful planning and preparation paid off? Had the infrasound really produced any spooky effects in our concert going guinea pigs? If so, this would be the first experimental evidence to suggest that Vic was right to think that some alleged ghostly experiences may be due to low-frequency sound waves. The good news was that no member of the audience had experienced the dreaded “brown note” phenomenon. The very good news was that, as predicted, they had reported significantly more strange experiences during the pieces that incorporated infrasound. The effect was far from trivial, with people reporting, on average, about 22 percent more unusual experiences with infrasound present. People’s description of their unusual experiences made for fascinating reading. When the infrasound was flooding into the concert room during one piece, one audience member reported a “shivering on my wrist, odd feeling in stomach”; another said that he had an “increased heart rate, ears fluttering, anxiety.” At another point in the concert, one man said he “felt like being in a jet before it takes off,” and a woman reported a “pre-orgasmic tension in body and arms, but not in legs.”
These findings were reported by the world’s media. As a result, the team was contacted by theme parks asking whether they could use infrasound to make their scariest rides even more terrifying. But this was not the most curious spin-off from the project. We had shown that some “ghostly” experiences may be caused by infrasound. And some academics have taken the idea one step further, suggesting that the same low-frequency waves might also play a key role in creating allegedly sacred experiences. Aeron Watson and David Keating from Reading University have constructed a computer model of a Scottish Neolithic passage grave.
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Using this model, the researchers have argued that the site has an infrasonic resonant frequency such that a person beating a 30-centimeter drum could produce powerful low-frequency sounds.
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Others have suggested that some large organ pipes found in certain churches and cathedrals are also capable of producing similar effects.
As part of the preparation for the concert, the team visited several churches and cathedrals that contained especially large organ pipes and discovered that some were indeed creating significant levels of infrasound. This suggests that people who experience a sense of spirituality in church may be reacting to the extreme bass sound produced by the pipes. Further support for the idea came from one pipe manufacturer who informally told the team that the sounds from these pipes are inaudible, and that they can be viewed either as a very expensive way of creating a small draft or as a cost-effective way of helping the congregation find God.
4
MAKING YOUR MIND UP
The Strange Science of Decision Making
I
magine that you decide to buy a nice new calculator. You go to your local electronics store and the salesperson shows you a range of devices. After careful consideration, you choose a model that costs $20. At this point, the clerk looks slightly anxious and explains that the following day the store is going to have a sale. If you come back then, the calculator will cost $5. Do you buy the calculator then and there, or return the following day?
Now let’s imagine a slightly different scenario. This time you decide to buy a new computer. You’re shown a range of machines. After careful consideration, you choose a computer costing $1,999. Once again, the assistant looks anxious, and then explains that the following day there will be a sale. If you come back then, the computer will be reduced to $1,984. Do you buy the computer, or return the following day?
Researchers examining the psychology of decision making have presented these two scenarios to lots of people. In both instances, there is the opportunity to save identical amounts of money, and so it would be rational to treat each choice the same way. People should either buy the calculator and computer right away or, if they want to save $15, return the following day. However, most people treat the two scenarios very differently. About 70 percent of people say that they would put off buying the calculator until the following day, but purchase the computer right then and there.
Even without a calculator, it is clear that the figures don’t add up. Why do so many people act in such an irrational way? It seems that they view their potential saving not in absolute terms but rather as a percentage of the amount of money they are spending. In absolute terms, each time they stand to save $15. However, this represents 75 percent of the price of the calculator, but just 1.5 percent of the price of the computer. Seen in relative terms, the former seems to be a much better deal than the latter, and so well worth waiting for.
This is just one example from the large amount of research investigating how people make up their minds. The work has examined how people make many different types of decisions, including whom they should marry, which political party they should support, the type of career they wish to pursue, the sort of house they should live in, the size of car they should have, and whether they should give it all up and move to the countryside.
Here are just a few of the questions this unusual research has explored: whether subliminal messages can increase sales of Coke, popcorn, and bacon; whether something as simple as the height of political candidates can cause voters to switch allegiance from one party to another; whether your surname influences where you live and the career you pursue; whether Hollywood movies influence the verdicts returned in courtrooms around the world; and why certain online chat rooms and personal ads are more effective than others.
We start by delving deep into the strange world of subliminal perception.
DRINKING COKE, EATING POPCORN, AND BUYING BACON
In September 1957, a market researcher named James Vicary announced the results of a remarkable experiment proving that subliminal stimuli exerted a powerful influence over people’s buying behavior.
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According to Vicary, moviegoers in New Jersey had been secretly exposed to the subliminal messages “Drink Coke” and “Eat Popcorn” while watching their favorite films. The messages had been flashed onto the screen from a high-speed projector designed by Vicary, with each exposure lasting just one three-thousandth of a second. Although the audience had been unaware of the messages, sales of Coke and popcorn had increased by 18 percent and 58 percent, respectively. Vicary’s announcement generated a considerable furor among the public and the politicians. Could people’s thoughts and behavior really be manipulated by subliminal messages? Could they be persuaded to buy products they didn’t want, to vote for politicians they didn’t support? Could these messages even be broadcast on national television and influence an entire nation?