From de facto sound, you're listening to 20,000 Hertz.

The stories behind the world's most recognizable and interesting sounds.

I'm Dallas Taylor.

This is the story of how our bodies and minds are actually shaped by sound.

Sounds can startle us, make our hearts race.

Sounds can cause us to cry, to laugh, or bring us into a deep meditative state.

There are so many sounds that impact our bodies on a daily basis.

I mean, to start, just think about the sounds that might interrupt an otherwise peaceful

day.

For example, a police siren.

Blaring by as we commute to work.

And what about the cries of an unhappy baby?

Or a vacuum cleaner waking you up from your Saturday nap?

Whatever the sounds, good or bad, we want to get to the bottom of what leads us to make

judgments about those sounds.

What's going on in our brains that make us evaluate sounds in the ways that we do?

And is there any truth to that lurking feeling that for some sounds, we all kind of hold

a similar judgment?

I mean, is there someone out there who likes the sound of fingernails on a chalkboard?

And a tiny aside here.

I want to pledge to you right here and now that this won't be an episode of completely

cringe-inducing sounds.

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