The Silent Treatment
We all know about diminishing oil, dwindling water, food scarcity and endangered species, but there’s another disappearing resource among us that’s less noticeable: silence.
Trying to find a quiet space in the modern urban environment is nearly impossible. We live in a noisy world of roaring freeways and blaring ringtones. Even our traditional go-to sanctuaries have brought the noise: Airplanes regularly rumble over our bedrooms, and our libraries have gone all clamorous and interactive.
The scarcity of silence is a topic on the mind (and ears) of Trevor Cox, Salford University professor and author of The Sound Book: The Science of the Sonic Wonders of the World. In this excerpt in American Scientist, Cox seeks out some of the quietest places on the planet — places unpolluted, by nature or by design, with artificial sound. Encouragingly, one of those places is just south of us at Kelso Dunes in the Mojave National Preserve:
While I was on an expedition to record singing sand dunes, I experienced something quite rare: complete silence. The scorching summer heat kept visitors away. Most of the time my recording companion, Diane Hope, and I were on our own. We camped at the foot of Kelso Dunes, in a barren, scrubby valley with dramatic granite hills behind us. Virtually no planes flew overhead, and only very occasionally did a distant car or freight train create noise. Much of the day there was a great deal of wind, but at twilight and early in the morning the winds calmed down and the quiet revealed itself. Overnight I heard the silence being interrupted only once, when a pack of nearby coyotes howled like ghostly babies.
Sounds peaceful. Almost ... too peaceful. Curiously, Cox does find in his research that, yes, there is such a thing as deafening silence, and there is such a thing as the kind of menacing aural absence that can lead to a sensation of ants crawling on your brain. Even in the desert quiet of Kelso, he notices that the absence of sound compels his brain to stage a coup and start supplying its own noise — one theory to explain tinnitus, a chronic ringing in the ears:
Theories of tinnitus abound, but most experts agree that it is caused by some sort of neural reorganization triggered by diminished input from outside sounds. ... In a silent place, or when hearing is damaged, auditory neurons in the brain stem increase the amplification of the signals from the auditory nerve to compensate for the lack of external sound. As an unwanted side effect, spontaneous activity in the auditory nerve fibers increases, leading to neural noise, which is perceived as a whistle, hiss, or hum. Maybe what I was hearing on the dunes was the idling noise of my brain while it searched in vain for sounds.
But the aural mirages inspired by Kelso are a minor annoyance compared to some of the trippy effects induced by even quieter places he writes about — like the anechoic chamber at Salford University in Manchester. Get this: It’s so quiet that its sound levels are measured in negative decibels, which make the room not so much a sanctum of quiet serenity as a sensory distortion chamber that can freak out visitors with a psychic version of nails on a chalkboard:
An anechoic chamber has an impressive silence because it simultaneously presents two unusual sensations: Not only is there no external sound, but the room puts your senses out of kilter. Through their eyes, visitors obviously see a room, but their ears hear nothing that indicates a room. Add the claustrophobic drama of being enclosed behind three heavy doors, and some begin to feel uneasy and ask to leave. Others are struck with fascination at the oddness of the experience. I know of no other architectural acoustic space that regularly has such a strong effect on people. But it is remarkable how quickly the brain gets used to the silence and the contradictory messages from the senses. The magical impact of the first visit to an anechoic chamber is never really experienced again.
Silence is golden — and a rarity in the cacophony and caterwaul of modern life. Maybe we’d all do well to have our own anechoic chambers to gather our thoughts and calm our restless souls. Just don’t stay in there too long.
Copyright 2015 KNPR-FM. To see more, visit http://www.knpr.org/.