The "silent" room at the Redmond complex of the US technology giant Microsoft is the quietest place on the planet.
The room is used to perform sensitive tasks that require quiet, including adjusting the headset and improving mouse clicks.
The company found the room very quiet for most people and no one could stay more than 45 minutes indoors.
A few who entered the room complained about the high sound of their breathing and the sensation of an annoying belly in the ears.
"Some people come for a minute and want to get out right away," said Hondraj Gopal, Microsoft's chief human factor engineer who led the room's Echoing Team, "People can not cope with the atmosphere of the room. They are cluttering their brains."
He also revealed that the room cost alone amounted to $ 1.5 million, which shows how serious the company is about sound design.
The room, measuring 6.36 meters in each direction, is designed to be as quiet as possible to allow engineers to adjust sound and sound devices in ideal conditions.
The room is surrounded by six layers of concrete, each with a thickness of 12 inches, which helps to block sounds from the outside world.
The walls, the floor and the roof are covered with giant foam-fiber pegs to get rid of the echo.
The chamber floats on 68 springs of vibration damping springs, mounted on a separate baseboard separated from the rest of the building.
The floor was designed from steel ropes used to stop fighter aircraft as they landed on aircraft carriers.