Scientists have long struggled to study how whales produce sound. A new paper in the journal Nature paints the most complete picture yet of how baleen whales produce their iconic, haunting calls.

COEN ELEMANS: All the baleen whales make extremely low frequency sounds, and it sounds like a bit like humming, like, (imitating whale sound), something like this. And it's really hard for me to do ...

KELLY: It's the song of a humpback whale, a type of baleen whale. COEN ELEMANS: All the baleen whales make extremely low frequency sounds, and it sounds like a bit like humming, like, (imitating whale ...