A room in the Orfield Laboratories in South Minneapolis is the quietest place on Earth and you might be surprised to learn that your brain can only tolerate so much silence before you begin to hallucinate. Inside the room, you will hear the sound of your lungs expanding and contracting, your stomach digesting food, even the sound of your own heartbeat. Without sound feedback to assist your equilibrium, if you stand up, you will likely become disoriented and stumble. At most, you will be able to tolerate the “golden silence” for no more than 45 minutes. Even Mr. Oldfield, the owner of the sound chamber, admits that he can stay in the room for no more than 30 minutes. The sound of his heart valve drives him crazy.
Mr. Oldfield explained:
“When it’s quiet, ears will adapt. The quieter the room, the more things you hear. You’ll hear your heart beating, sometimes you can hear your lungs, hear your stomach gurgling loudly. In the anechoic chamber, you become the sound. And this is a very disorientating experience. It’s so disconcerting that sitting down is a must. How you orient yourself is through sounds you hear when you walk. In the anechnoic chamber, you don’t have any cues. You take away the perceptual cues that allow you to balance and maneuver. If you’re in there for half an hour, you have to be in a chair.”
Any sound below 0 dBA is undetectable by the human ear. The Orfield sound chamber has an astonishing decibel rating of –9.4 dBA. With 99.99% of the sound absorbed by the specially constructed walls, the “anechoic chamber” achieves its unusually quiet environment using 3.3 foot thick fiberglass acoustic wedges, double walls of insulated steel, and concrete one-foot thick. Scientists challenge people to sit in the dark room. The record is 45 minutes.
The chamber is used by companies to test the loudness of their products and to detect small sounds that their devices make (such as the sound of a switch in an automobile). NASA puts astronauts in it (inside a water tank no less) to test how well the astronaut will be able to handle the silence of space while remaining focused on their work. Harley Davidson used the room to test the loudness of their bikes in an effort to build a quieter Harley that still retained the classic Harley Davidson sound. And we can all appreciate that Whirlpool used the room to help build a quieter washing machine.