This week, we explore communication: how do we talk? how do we hear? and what the hell are we even saying? And what about the rest of the animal kingdoms? African elephants don’t just communicate through trumpeting – they also use seismic waves. Elephant behavior expert Caitlin O’Connell explains this “second language,” and how it’s helping advance hearing aid technology. She also tells us about her new work of fiction, Ivory Ghosts, which draws attention to the intensifying problem of illegal ivory trade. We then talk to evolutionary biologist Nicole Creanza, who explains that we can learn a lot about early human migration across the globe not just through genetics, but also through our languages.