(If you wanna get right to the whistle sounds, skip to around the 2:13 mark)

Imagine hearing this sound at night, in the woods.

The Aztecs thrived from around the years 1300 to 1521. So, this whistle that was recovered survived their downfall. It's probably because it holds the souls of all of them. The sound that this whistle makes is terrifying.

After you've listened to the sound, imagine 20 or 30 of those being blown from a distance that you can't see where it's coming from. That just makes it scarier.

Honestly, I'm not sure what these whistles were used for, but if I had to take a guess, they were used to scare the ever-lovin out of their enemies. I know I wouldn't dare go looking for the source of that sound.