If you were asked where the most silent place on Earth is, you might respond Antarctica or somewhere in the Sahara Desert, but you'd actually be wrong.

It's in Minnesota—where among the many buildings of Orfield Laboratory lies the Anechoic Chamber, a place so scientifically configured to absorb sound, that a mere blink becomes deafening.

The ambient noise inside the Anechoic Chamber is at negative decibels—minus-24.9 dBA to be exact—which is a Guinness World Record and so quiet that it's actually below the threshold of human hearing. With zero sound of any kind, visitors, who sometimes can hardly stand the silence, report hearing their body's minute functions like blood pumping and eyes blinking.