In 2015 Microsoft created what is considered by the Guinness Book of Records as the quietest place on the planet. It is a room full of curious wedge-shaped panels that absorb sound and make the room so quiet that it is overwhelming: no human being can last more than a few minutes in it.
anechoic chamber. To make the panels in this room absorb all the sounds, Microsoft engineers used six layers of cement and steel and “disconnected” the room from the main building. To do this, they placed it on top of a matrix of springs capable of damping vibration.
Inside, they used fiberglass panels on the floor, ceiling, and walls to “break up” the sound before it has a chance to bounce back into the room. We were already able to do some very special tests in a camera of this type: some aimed at measuring the radiation emitted by different smartphones.
What is this room used for?. Microsoft uses that ability for something very striking: studying what noise all kinds of elements of its products make—connecting them to the current, turning them on, pressing buttons—to assess whether or not they are too noisy. The idea: that the noise does not bother us. Being able to measure those noises with this room is an excellent way to avoid complaints and problems later. That is where, for example, they evaluated the behavior of their voice assistant, Cortana.
decibels. Any particle in the air moves randomly —Brownian motion— and collides with the molecules of the air (or liquid) in which it moves. In doing so, it generates noise, but that noise is absolutely imperceptible to the human ear, and is around -23 decibels (dB).
In a quiet office the noise is around 40 dB. Noise pollution in Madrid is around 65 dB during the day and 55 dB at night. A conversation causes a noise of 60-65 dB, a vacuum cleaner about 80 dB, a rock concert about 105 dB and an airplane 150 dB (100 m away). Do you know how much noise there is in this room?
-20.3dB. The measurement is spectacular, and it was the one that Microsoft engineers achieved in October 2015 when they registered the Guinness record. The goal, by the way, was to get to -13 dB. Currently engineers at Orfield Laboratories in Minneapolis are working on another anechoic chamber that they say achieves -24.9 dB. In the Guinness Book of Records they are checking if the measurement is valid, which would make this room the new quietest place in the world.
No one can last an hour there. The room is so quiet that it ends up being oppressive for the human being. Within a few minutes you hear the sound of your heart, and shortly after you also hear your own blood flowing through your veins or your bones moving. That almost absolute silence causes an unbearable ringing to end up appearing in your ears. The lack of reverberation ends up making one lose balance and our spatial perception.
a deafening silence. As Microsoft engineers explained on CNN, “Most people feel the absence of sound as deafening, and have the sensation of full sound in their ears, or some kind of whistle. […] When you turn your head, you can hear the movement. You can hear your breathing and it’s surprisingly loud.”