Drum roll for...Orfield Laboratories in Minnesota, awarded by the Guinness Book of World
Records 'The Quietest
Place on Earth.'
How do they do it?
Start with a room
within a room, within a room. A six-sided anechoic
chamber floats over a pit on I-beams that sit on top of
springs. And then a five-sided chamber of identical construction surrounds all that.
Both chambers are made of double-wall
steel-insulation-steel and are held within a larger room that was built with solid one
foot thick concrete walls and ceiling panels. (Keeping up?) The smaller room is filled
with 3.3 feet thick fiberglass acoustic wedges.
On January 21st of 2004 engineers measured the room at negative 9.4 dB (with A-weighting), thus
earning it the GBOWR title.
The result is that all reverberation is removed; all sounds that aren't coming from your own body disappear. After a few moments in the anechoic chamber you hear your heart beat, your blood pulse, and the sound of your own ear buzzing and your body functioning like you've never heard before.
In complete silence, you lose all sense of space and surroundings. The absence of reflected sound and reverberation makes "feeling out" the room impossible.
"Why?" you're asking.
Orfield Labs specializes in acoustic research for a wide range of products, including motorcycles, dishwashers, and artificial heart valves.