- -20.35 decibel(s) (A-weighted)
- United States (Redmond)
The quietest place in the world is the anechoic chamber at Microsoft Headquarters, Redmond, Washington, USA. Ultra-sensitive tests performed on 10 June 2015 gave an average background noise reading of -20.35 dBA (decibels A-weighted).
Two ultra-sensitive tests were performed in the chamber. One test result was -20.6 dBA and the other was -20.1 dBA.