Catalyst: Acoustic Ecology Lab

“Catalyst” explores the importance of listening and how the environment and our hearing are intertwined.

WATCH: See more from season 2 of “Catalyst”

Sponsor message:

In this segment:

Garth Paine, Sabine Feisst, Kyle Hoefer

Sponsor message:

American Experience: Citizen Hearst

Take a deeper look into the wild career of William Randolph Hearst in a two-part series from "American Experience."

In Their Own Words: Jimmy Carter

A new look at former President Jimmy Carter displays fresh perspectives of family members, journalists, colleagues and more.

In Their Own Words: Elon Musk

Elon Musk is part of a new breed of "thrillionaires" — high-tech entrepreneurs using their wealth to turn science-fiction dreams into reality