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The quietest place on Earth, where you can hear your eyes blink, is in...
Due to its design, the ambient sound levels in the chamber are so low that they fall below the noise floor.
Have you ever heard your eyelids blinking or blood flowing through your veins? It might sound strange, but there is a place on Earth where you can actually hear sounds like these.
This place, the quietest on Earth, is the anechoic chamber at Orfield Laboratories in Minneapolis, Minnesota, USA.
Most of the chambers and anechoic rooms at Orfield Laboratories are designed to accurately measure the sound produced by various items. The chamber consists of a large room made of concrete and masonry, lined with 10.5 cm thick steel plates. Inside this, there is a smaller steel room suspended by springs that absorb vibrations, as stated by Guinness World Records.
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Room's design
The custom design includes heavy insulation and glass-fiber wedges that extend 85 cm into the room and the floor to prevent sound transmission. Users must stand on a suspended mesh to minimize sound transfer from the ground. The room’s usable dimensions are 3.7 x 3.1 x 3.52 metres.
Due to its design, the ambient sound levels in the chamber are so low that they fall below the noise floor. This means that even the background electrical hiss of the most sophisticated scientific instruments is quieter than the noise floor in the room. To measure accurately in this environment, two Brüel & Kjær type 4145 microphones, each with its own preamplifier, were used, according to reports.
As electrical noise is random, the two microphones were exposed to slightly different noise between the channels. However, the measurement of the room itself remained unaffected by this noise. The final reading was determined by cross-correlating the signals from both microphones and using the matching parts of the signal.
