The world's quietest room is so silent that you can hear your own blood flowing through your veins.

Located in Building 87 at Microsoft's headquarters in Redmond, Washington, this anechoic chamber holds the Guinness World Record for the quietest place on Earth. In 2015, tests measured the background noise level at -20.35 dBA. For context, the sound of air molecules colliding is approximately -24 dBA, meaning this room approaches the absolute physical limit of silence.The chamber uses a "room-within-a-room" design with six layers of concrete and steel to block external vibrations. Inside, the walls, floor, and ceiling are lined with large fiberglass wedges that absorb sound waves before they can reflect. This prevents any echo, creating a completely "dead" acoustic environment far below the threshold of human hearing.When external noise is removed, the human auditory system automatically amplifies its sensitivity to detect signals. This causes you to perceive internal bodily functions that are normally masked by ambient sound. Visitors frequently report hearing blood rushing through their cerebral arteries and the audible clicking of their bones moving. This sensory deprivation often leads to disorientation and mild hallucinations within 30 to 45 minutes.