Imagine a place so quiet, you can hear your
heart beat, your lungs breathe and your stomach digest.
The anechoic (meaning echo-free) chamber at Orfield Labs
in Minnesota absorbs 99.99% of sound, making it the quietest place in the world,
according to the Guinness Book of World Records. To absorb all possible noise,
the chamber walls are made from 3ft of sound-proofing fibreglass wedges and
insulated steel and concrete, and the floors are covered in a semi-permeable, trampoline-like mesh.
While a human can normally hear sounds as low
as zero decibels (an average conversation runs at about 30 decibels), the
background noise in the anechoic chamber has been measured at -9.4 decibels. This
sensory deprivation makes the room extremely disorienting, and people can rarely
stay in the dark space for longer than 45 minutes. Without the subtle, but
vital auditory feedback that establishes a human’s sense of space, balance and
walking become a challenge.
The chamber is not just for fun, though. Companies
use the chamber to test the sound levels of products, such as washing machines,
refrigerators and Harley Davidson motorcycles. NASA uses a similar chamber to
perform stress tests on astronauts.
tours of the labs are available a few times a year and include a brief stop
at the anechoic chamber (call the lab for details). But the facility has had so
much interest in the 45-minute challenge that the founder Steven Orfield is
considering making that option available to the public within the next year,
and is working with the Guinness Book of World Records to establish an official
record for the longest time spent in an anechoic chamber.
The 45-minute challenge will not come cheap,
however, as companies renting the space normally pay $300 to $400 an hour, and
someone trained from the lab must be able to supervise the participants to
ensure their safety.