Would You Rather Spend an Hour in a Wind Tunnel or an Anechoic Chamber?

You’re standing inside a funnel-shaped room, wearing a harness with long straps attached to the floor. A massive fan behind you starts to spin. The whirling blades suck air out of the room, creating a powerful airstream. The straps keep your feet planted on the floor as your clothes and hair flap in the wind. The skin on your face gets smooshed back. It feels like sticking your head out the top of a speeding car—but way more extreme! This is what it’s like to stand in a wind tunnel.

Wind tunnels were developed to study aerodynamics—how air flows around objects. Engineers use these machines to learn how to make products faster, safer, and more efficient. Wind tunnels can be used to test how objects like tents or road signs handle varying wind speeds, so they can be designed not to break or blow away. They’re also used to examine how the slowing force of air resistance affects cars, bikes, airplanes, and even spacecraft as they move.

Wind tunnels can be small or large. The most powerful ones can generate wind speeds of up to about 24,700 kilometers (15,300 miles) per hour. That’s nearly seven times the speed of the fastest fighter jet! Even in a low-speed wind tunnel, “it feels like you’re in a hurricane,” says Cara Winter, who directs wind tunnel operations at the University of Washington Aeronautical Laboratory. “As wind speed increases, it gets harder and harder to stay standing,” she says. “And it’s super loud, so you want to wear protective earmuffs.”

You’re standing inside a funnel-shaped room. A harness with long straps attaches your body to the floor. A huge fan behind you starts to spin. The spinning blades suck air from the room. They create a strong stream of air. The straps keep your feet on the floor. Your clothes and hair flap in the wind. The skin on your face gets smooshed back. It feels like sticking your head out of a speeding car. But it’s more extreme! This is what it’s like to stand in a wind tunnel.

Wind tunnels were developed to study aerodynamics. That’s the way air flows around objects. Engineers use these machines when developing products. Wind tunnels help make things faster, safer, and more efficient. Wind tunnels can be used to test how objects handle different wind speeds. That way things like tents and road signs can be designed not to break or blow away. People use wind tunnels when designing cars, bikes, airplanes, and even spacecraft. The tunnels show how the slowing force of air resistance affects these objects.

Wind tunnels can be small or large. The strongest ones can create wind speeds of up to about 24,700 kilometers (15,300 miles) per hour. That’s nearly seven times the speed of the fastest fighter jet! Even in a low-speed wind tunnel, “it feels like you’re in a hurricane,” says Cara Winter. She directs wind tunnel operations at the University of Washington Aeronautical Laboratory. “As wind speed increases, it gets harder and harder to stay standing,” she says. “And it’s super loud, so you want to wear protective earmuffs.”

Imagine a place so quiet that you can hear your own heartbeat. It’s a windowless room where wedges of fiberglass—a lightweight material made from fine glass fibers—cover every wall. The soft and pointed shapes absorb any sound waves you produce. You’re inside an anechoic chamber.

Anechoic (a-nih-KOH-ik) means “without echo.” In an anechoic chamber, sound waves can’t reflect off the walls, so any sounds produced inside are dampened. To block out external noise, chambers are built inside a steel box that’s suspended by springs inside another steel box, surrounded by an even bigger concrete room. Inside, you’re completely cut off from the world, says Emma Orfield Johnston. She works at Orfield Laboratories in Minnesota. Her lab’s anechoic chamber holds the record for quietest place on Earth, with a noise level of -24.9 decibels. Anything below zero decibels is too quiet for humans to detect.

Anechoic chambers are typically used to test the sound quality of products like loudspeakers, refrigerators, or motorcycles to help make sure they aren’t annoyingly loud. When people enter an anechoic chamber for the first time, the silence can feel extreme. “For some people, it’s relaxing,” says Andy Piacsek, a physics professor who studies sound at Central Washington University. “For others, it’s disorienting.” With no sound bouncing back, visitors can hear their eyelids blink. Most people can't withstand being inside Orfield’s anechoic chamber for more than 45 minutes.

Imagine a place so quiet that you can hear your own heartbeat. It’s a windowless room. Wedges of fiberglass, a lightweight material made from glass fibers, cover every wall. The soft and pointed shapes absorb any sound waves you produce. You’re inside an anechoic chamber.

Anechoic (a-nih-KOH-ik) means “without echo.” In an anechoic chamber, sound waves can’t reflect off the walls. So any sounds produced inside are dampened. To block out external noise, chambers are built inside a steel box. The box is suspended by springs inside another steel box. The larger box is surrounded by a concrete room. Inside, you’re completely cut off from the world, says Emma Orfield Johnston. She works at Orfield Laboratories in Minnesota. The anechoic chamber there holds the record for quietest place on Earth. The noise level inside is just -24.9 decibels. Anything below zero decibels is too quiet for people to hear.

Anechoic chambers are used to test the sound quality of products. Engineers need to make sure that loudspeakers, refrigerators, or motorcycles aren’t annoyingly loud. The silence in the chambers can feel extreme. “For some people, it’s relaxing,” says Andy Piacsek. He’s a physics professor who studies sound at Central Washington University. “For others, it’s disorienting.” Visitors can hear their eyelids blink. Most people can't stand being inside Orfield’s anechoic chamber for more than 45 minutes