I spent an hour with four strangers in the quietest room in Minneapolis (and the world)

It's so silent inside the quietest room on Earth that you can hear your eyelids shut when you blink.

Tucked away in Minneapolis' Seward neighborhood, Orfield Laboratories has made a name for itself in the business of silence.

Ordained by Guinness World Records as the quietest place on Earth, the anechoic chamber at Orfield Labs is measured at an average of -13 decibels and a record of -24.9 decibels. Zero decibel is the threshold for human hearing, meaning -24.9 is a whole lot of nothing.

Yet the emptiness of the chamber feels heavy when you spend an hour inside with four strangers and the lights off. I went last Friday to the first of a series of group tours offered by Orfield Labs. The tours cost $75 per person and are nearly sold out, though more may be offered. I jumped at the opportunity.

A group session inside the chamber isn't the quintessential quietest-room-in-the-world experience, but it's the closest most people will ever get to perfect silence, said Steve Orfield, founder of Orfield Labs.

A long corridor snakes through the interior of the building, with a set of heavy doors leading into the chamber and an outermost wall of 12-inch-thick concrete. Emma Orfield Johnston, granddaughter of Steve Orfield, assured us that we wouldn't be trapped in the room.

The first thing that surprised me is the imposing otherworldliness of the 3-feet fiberglass wedges jutting from the chamber walls at varying angles. The smallness of the room became apparent as four strangers took seats around me. The platform we stood on was suspended over a net of aircraft cables with vibration-dampening springs below.

The lights would be turned off to ensure a fully immersive experience. Luckily, the four strangers sharing the dark were friendly. Two flew from Arizona just for the tour.

People with hearing loss tend to hear ringing in their ears while inside the chamber, Orfield Johnston said. To my horror, tinnitus was waiting as soon as the chamber door closed and the lights went off.

The loudest sound inside the chamber would be a creation of my own mind, a mistranslation of the distorted vibrations my ears were sending to the brain.

My group followed the no talking or phone use rules. Still, our bodies seemed in communication as disembodied rumbling and squelching of stomachs rose from the darkness. Anxiety creeped from within as I worried my bodily machinations were the loudest – I had skipped breakfast that morning.

The sound of swallowing was so loud I convinced myself my throat was drier than the Sahara. The slightest shift of the body created an embarrassing cacophony for my comrades in silence. At one point, I staunchly resisted a burp only for it to transform into an even stranger sound. I'd be dead last if this was a competition.

With little external stimuli, I needed to think of things to think about. My grumbling stomach, my poor sleep habits, my brother's first day at his new job, a long-gone golden retriever named Autumn, hours spent lying on my grandma's patio swing set and staring up at the tree canopy scattering the light like a kaleidoscope.

I thought of a line from the science fiction novel "Cloud Atlas" that hasn't left me since I first read it: "the mind abhors a vacancy & is wont to people it with phantoms."

And provide phantoms my mind did.

Inside the pitch-black chamber, the only difference between your eyes being open or closed is the phantoms your mind creates from the emptiness. There was a white glow here and there and a pink blob floating across my vision like a strange object drifting across the expanse of a starless night sky.

I lost nearly all sense of time. I knew it had been longer than five or 10 minutes, but had it been 20, 30 or 40? I had missed the bus and time had moved on from this realm I now shared with faces and bodies I could no longer picture.

Anxiety returned as I doubted whether I could last another 30 minutes. I started to feel itchy in random places, scratching like a game of Whac-a-mole.

Just as I managed to calm down, a glimpse of light appeared in the corner of my eye and slowly widened. The door was open. It was over. I survived.

My group exchanged thoughts in hushed tones, only beginning to return to the loudness of our world. Some said they could hear their heart beating, but I missed that. As we parted ways, my mind felt clear in a way it rarely does.

When I got home, I collapsed into bed and Googled "hearing loss."