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 the THX Deep Note, part two.

That somewhat ominous sound you just heard is the THX audio logo known as the Deep Note.

At first, it seems to go everywhere, and nowhere.

And then comes together at the end for a larger-than-life resolution.

The Deep Note is an announcement that's been played during the trailers and movie theaters for decades.

It started way back in 1983.

It let audiences know that they were in a THX certified theater and that their audio experience would be phenomenal.

THX certification was pioneered by George Lucas.

It made sure that return of the Jedi would be experienced with the best sound theaters could provide.

In the last episode, we explored how Andy Moore used cutting-edge computer technology to make it.

We also found out that everyone at Lucasfilm loved it, but before it could be used in theaters, they lost the only recording of it.

We'll get to that in a moment.

But first, let's hear what sound people think when they hear the THX Deep Note.

Our producer Kevin Edds took a stroll around our studios here at De facto Sound to hear what our staff thinks.

I think at some point in my life, it did feel uncomfortable.

And actually, like the thing that reminds me of the most of this, at the very, very beginning of 2001, a space Odyssey, when it's just black.

And there's just this very dissonant creeping score.

And there's just no visual with it at all.

And it kind of reminds me of that, that it's interesting feeling why does this make me uncomfortable.

And then so quickly, it changes from that to just feeling like this big, epic thing.

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