Silence is a hidden treasure in today’s world. And with the world moving at a rapid place, sound quickly becomes noise and the humans find themselves submerged in it. From tapping of keys to hammering sounds on roads, the human brain is never really quiet.
But Microsoft‘s Building 87 has managed to become the quietest place on Earth. A specialised anechoic chamber, it locked out from the rest of the world and any sound produced inside cannot possibly escape.
Located in Redmond, Washington at the Microsoft head office, the chamber even made a Guinness World Record for being just above the decibel levels of Brownian Motion – the quietest sound on earth at -20 dB. Resistant to echoes, the clapping sounds will sound eerily similar to a creepy background noise.
A silent sensory experience
“As soon as one enters the room, one immediately feels a strange and unique sensation which is hard to describe,” wrote Hundraj Gopal, a speech and hearing scientist and the principal designer of the anechoic chamber at Microsoft, in an email.
The ‘background’ noise in the room is so low that is nears the absolute zero of sound, with the next step being vacuum.
Describing what it feels like to step into an anechoic chamber, Gopal said the experience is unlike anything most people have encountered. “Most people find the absence of sound deafening, feel a sense of fullness in the ears, or some ringing. Very faint sounds become clearly audible because the ambient noise is exceptionally low. When you turn your head, you can hear that motion. You can hear yourself breathing and it sounds somewhat loud,” he explained.
According to Gopal, the strange sensation stems from the fact that our ears are rarely exposed to complete silence in everyday life. In the outside world, there is always a background layer of sound—whether it’s distant traffic, air conditioners, or the rustle of leaves—which creates a constant level of air pressure on the eardrums. Inside an anechoic chamber, however, that familiar acoustic environment disappears entirely. Because the specially designed walls absorb sound instead of reflecting it, there is virtually no echo or ambient noise, leaving the ears without the constant sound reflections they are accustomed to.
“This is a novel experience,” Gopal wrote, highlighting why many first-time visitors find the chamber both fascinating and deeply unsettling. In the near-total absence of external noise, the body’s own sounds—from breathing and swallowing to subtle movements—suddenly become impossible to ignore.
How the room was built
Achieving near-perfect silence requires far more than simply building thick walls. The anechoic chamber is engineered with an “onion-like” structure, featuring multiple protective layers that isolate it almost completely from both the rest of the building and the outside world.
The room is constructed using six layers of concrete and steel, creating a formidable barrier against external noise. It is also physically separated from the surrounding structure, resting on an array of specially designed vibration-damping springs that minimise even the slightest tremors from footsteps, traffic, or nearby machinery.
Inside, every surface has been carefully designed to eliminate sound reflections. Sharp fiberglass wedges line the walls, ceiling, and even the floor, absorbing and scattering sound waves before they have a chance to bounce back and create an echo. Instead of a solid surface, the floor consists of a suspended grid of sound-absorbing cables, allowing the wedges beneath to continue trapping sound. Together, these engineering innovations create one of the quietest environments imaginable, where almost every external sound is eliminated and even the faintest noises made by the human body become strikingly audible.