Emily Kwong

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Last year, host Noam Hassenfeld did a five-part series about the way our brains process sound.

It's called The Sound Barrier, and their second episode is about tinnitus.

That's when you perceive a ringing in your ear, this persistent sound that comes from nowhere.

Almost 15% of adults suffer from this, and there is no cure.

In fact, researchers are only just beginning to understand the cause.

Here's that piece, and you can check out the rest of The Sound Barrier series on the unexplainable podcast.

podcast feed.

Enjoy.

Even a slight impact on the wall could cause the brain to move within the skull.

And no helmet is going to protect you from that.

Okay, so you got luge.

That's where athletes are lying on their backs and initiating those turns with their very strong calves.

And then there's skeleton, which I think has the coolest helmets in the Olympics because those athletes are racing head first.

Uh-huh.

The helmets are definitely aimed to get that racer, to get that athlete going as fast as possible.

Cool as this looks, this sport, all these sports, they come with broken bones.

They come with concussions and one of the lesser known ailments, sled head.

Wow, my dad would really appreciate that joke.

The umbrella term of sled head describes a wide range of symptoms.