Gordon Hempton believes there’s a reason why “peace and quiet” is a common phrase. It’s because quiet cultivates peace.

Hempton, an acoustic ecologist who’s been recording the sounds of nature for more than 40 years, has witnessed the adverse effects of noise pollution on public health and the environment. Now, as the co-founder of the nonprofit Quiet Parks International, he’s on a quest to preserve quiet spaces around the world, before peace and quiet become extinct.