Every living thing emits sound—birds sing, whales whistle, streams burble and trees pop and fizzle. In Listen Up, young readers are introduced to all the sounds of the natural world, from the first Big Bang to the complex soundscapes of the rainforests. Readers will also discover how the invasion of human sounds, from airplanes, traffic and machines, is threatening the survival of species that have adapted to their habitats over thousands of years. Conserving the sounds of nature is an important part of addressing the biggest challenges facing humanity today—protecting the planet's biodiversity and the future of our natural world.