You're listening to 20,000 Hertz. I'm Dallas Taylor.

In our busy modern lives, it's not often that we stop and really think about what we hear.

Most of the time, we just accept these human-made sounds without a second thought. But it's

important to remember that our world didn't

always sound this way. Matter of fact, the sound of our world changes constantly. Our cities and

towns sound completely different now than they did 50 or 100 years ago. So what will our cities

in town sound like 50 or even 100 years from now?

What if we could collectively sound design our world?

What would that Sonic Utopia be like?

And how can we get there?

In our future Sonic Utopia, there will certainly be sounds we want to remove.

The first thing that comes to mind is the screech of the New York City subway, which is incredibly loud and is sort of emblematic of the lack of updating of that city's infrastructure.

That's Rose Eveleth.

I'm the creator and host of a podcast called Flash Forward,

which is all about the future.

I love New York, but standing on the one train platform,

the train rolls in,

and you really feel like you're being stabbed in the ear.

We all know that loud noises can cause hearing loss,

but that's just the tip of the iceberg.

When we're exposed to loud noise, our bodies release stress hormones.

These hormones raise our blood pressure,

...