Microsoft’s new anechoic chamber now holds the Guinness World Record for the Quietest Place on Earth. The room, which was built by Eckel Noise Control Technologies, sits on anti-vibration springs that isolate it from the building’s foundation. The walls, floor, ceiling, and door are covered in wedges of sound absorbing material. Microsoft has an interactive website where you can take a look inside the record-setting room.
The chamber is located at the Microsoft Research Redmond Lab, just outside Seattle. At the lab, engineers use the anechoic chamber to test and improve products such as the Surface (tablet), HoloLens (virtual reality) and Cortana (personal assistant technology). In complete silence, they evaluate the acoustic properties of speakers, test microphone performance, and try to distract Cortana with various background noises.
This chamber gives us the opportunity to look for those really small signals that can have an impact to the end user. We always want to have the best tools available for the job. And that’s what this is. It’s a great accomplishment.
The new chamber is so quiet that it pushes the limits of physics. It could only be quieter if engineers could find a way to silence the air. Independent tests by professional sound specialists from Brüel & Kjær confirmed that the chamber’s sound floor is -20.6 decibels (dB), which is just slightly above the quietest known sound on Earth. Brownian motion, the sound of particles moving in a gas or liquid, is -23 dB. The chamber is actually closer to Brownian motion than it is to any other anechoic chamber. The previous record of -13 dB was held by another Eckel anechoic chamber at Orfield Laboratories in Minneapolis.
“We are absolutely thrilled with the results of our chamber for Microsoft,” said Eckel Vice President Jeff Morse. “Not only did we fulfill the requirements they needed for their testing, but we were able to deliver a facility that set a new world record. We couldn’t be more honored to have been part of this exciting project.”
Source: Business Wire | Microsoft | Photo by Guillaume Paumier 
