World's Quietest Room: Strange Facts About Extreme Silence

The world's quietest room is an anechoic chamber at Orfield Laboratories in Minneapolis, Minnesota. Guinness World Records lists its background sound level at -24.9 dBA.

An anechoic chamber is a special room designed to absorb sound instead of reflecting it. Thick insulation and large sound-absorbing wedges cover the inside, while the chamber's construction also helps isolate outside noise and vibration.

Because the room is extremely quiet, sounds from your own body can become much more noticeable. Visitors have reported hearing their heartbeat, breathing, stomach sounds, and even the movement of their eyelids.

An interesting detail is that negative decibels do not mean there is “negative sound.” Decibels use a reference level, so a negative reading simply means the measured sound is below that reference.

The practical takeaway: complete silence may feel very different from the peaceful quiet we experience at home. Removing normal background sound can make tiny sounds surprisingly noticeable.