The World’s Quietest Room

In 2012, Guinness World Records named the anechoic chamber at Orfield Laboratories the quietest place on earth. But you’ll find more than just a really quiet room inside this unassuming building in Minneapolis, Minnesota. From testing equipment to a reverberation chamber, Orfield Labs offers services in acoustics, vision, lighting, architecture and market research. Heading up the lab is Steve Orfield, a deep thinker who clearly looks at things with a unique and studied perspective. Together, Steve and his team, along with all their equipment, help make concert halls, religious spaces, restaurants and auditoriums as visually and audibly pleasing as possible. And when it comes to the world of audio, Orfield Labs’ two “sound” rooms test products we use every day, but in completely different ways.

Redefining quiet—the anechoic chamber

Designed to test, among other things, the output and continuity of audio equipment, anechoic, or echo-free chambers, completely absorb the reflections of sound while being insulated from exterior noise.

To achieve this, every wall, even the floor and ceiling, are padded with three-foot-thick acoustic wedges. The surface you stand on is wire mesh, suspending you in the space with the treated “floor” below you. The room is actually one room inside another — this prevents any sound or vibration from entering the space. As the doors of these two “separate” rooms close behind you, you’re encased in a chamber that is more deafening than silent, as you begin to hear your own heartbeat.

When Guinness did their testing, they rated this room at -13 dBA (decibels A-weighted). That’s 8 times quieter than most anechoic chambers, making it one of, if not the best for doing accurate product testing. That includes assessment in sound quality, sound dispersion, distortion and frequency response. With this information, audio brands like Sennheiser, Yamaha and many others have been able to design and create products that have greater precision, clarity and accuracy.


Crank up the reverb – the reverberation chamber

Down the hall from the world’s quietest room is a space that Mr. Orfield describes as being exactly the opposite. “This room is perfectly diffuse, perfectly reflective, while the anechoic chamber is perfectly absorbent.”

Being perfectly diffuse means the sound is even across the entire space, it doesn’t drop by more than a half decibel as you move across the room. This room measures the sound absorption of products and the sound transmission of things like walls, doors and windows. “We can measure sound reflection, sound absorption and sound power—which is the total amount of sound coming from a product,” Steve told us.

What silence can teach us about sound

While these rooms can teach us a lot about the output and absorption of audio equipment, they also teach us a good lesson in acoustic design. Orfield Labs does a lot of work with architects to create spaces that are acoustically pleasing. As Steve told us, “What we want is absolute clarity, we don’t want anyone to notice the sound system. So if you turn things back and let them be elegant, quiet the room—silence your heating and cooling system, and add in some good isolation from outside noises, then your sound will be incredibly clear, and you can let your ears relax and simply enjoy.”

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