You're listening to a celebration in the Levin-Aufe village and the remote

highlands of the island nation of Papua New Guinea.

I was here with our Scientific American video crew last year to make a documentary.

I and my co-producer Kasso Harper didn't know what any of these words meant. But as the entire village, men, women,

kids, grannies, swung their hips, waved branches, and sang in this beautiful heartfelt

chorus, we knew intuitively that we were being welcomed.

After all of the singing, we were invited to partake in a mumu.

It's this delicious feast that's made from wrapping meats and vegetables and

spices in banana leaves and then cooking them in this massive earth oven with steam

and hot stones.

Finding myself here in an island nation that's home to more than 300 tribes and about 858 different languages

was one of the most remarkable experiences of my entire life. Papua New Guinea also happens to be the most linguistically

diverse place on Earth. But that incredible diversity is declining. Half of the roughly 7,000

languages spoken today could be gone by the end of the century.

And Papua New Guinea, which hosts more than 10% of the world's languages,

is now finding its own linguistic diversity under threat.

After this experience, I had to learn more.

Where have we lost languages in other parts of the world,

and how have they been forgotten? Are we trying to bring them back? More importantly,

how do we trace the roots of our collective memory back to the very sounds that first made

us human? Were Scientific Americans science quickly, this is too leak a both.

Everybody said, why have you come?

...