World's Quietest Room

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World's Quietest Room, Anechoic Chamber In Minneapolis

The anechoic chamber is located at Orfield Laboratory in Minneapolis, Minnesota and was designed for testing out hearing aid equipment. To make sure no outside noises are present, the chamber is hidden behind two vault doors and has sound-deadening wedges covering all of the flat surfaces. Rather than sound bouncing off the walls, ceiling, and floor like a traditional room, the sound is absorbed.

http://www.huffingtonpost.com/2012/04/04/worlds-quietest-room-the-anechoic-chamber-minnesota-minneapolis_n_1403476.html