This week, Emily Hart takes you on a sonic tour of Colombia, with the Humboldt Institute’s Natural Sound Collection: not only are we going to be hearing about this amazing project, we are going to be listening to some of the more unusual and noteworthy sounds from the collection itself and exploring what they tell us about Colombia’s natural environments and those who inhabit them. We’ll hear a giant otter’s bark, the snore of a fish, a frog cocktail party, and mosquito love songs, plus bizarre and beautiful birds – along with a few other Colombian nature noises. We are joined by the collection’s curator, Hoover Pantoja – expert in bioacoustics, technological development, and innovation; and Curator of Birds, Gustavo Bravo - evolutionary ornithologist and expert in the systematics, ecology, and evolution of Neotropical birds. This soundbank – known as the Mauricio Álvarez Rebolledo Collection - is the second largest repository of natural sounds in Latin America, with more than 24,000 audio recordings - of 20 species of mammals, 1064 birds, 131 amphibians, 17 insects, and numerous ambient recordings of Colombia’s innumerable ecosystems. It has been built sound by sound since the 1990s, providing a crucial resource on a vastly underrated dimension of Colombia’s biodiversity, and ecology more generally. We’ll be talking about its evolution, from one man in the wilds of Colombia wielding a tape recorder through to the high-tech solutions – including of course artificial intelligence – being applied to the collection and the discipline more widely today. This sound bank is open to everyone - we'll be sharing the links so you can explore it for yourselves too. We are going to be journeying through the unseen universe of natural sound – sounds we often don’t or even can’t hear - talking about which animals have evolved to make and hear sounds - and why, and how sound can be used to understand evolution and measure the health of ecosystems. In the next hour, we’ll travel across Colombia from the Amazon to the Eastern Plains and beyond – with an unplanned but somewhat inevitable detour through Central Medellin.