Digital bioacoustic collections preserve important behavioural and ecological traits, as well as trackable evidence of the presence of species in space and time. Well-structured and open-source repositories provide valuable information for science and biodiversity conservation. Here, we introduce the Environmental Sound Collection - 'Mauricio Álvarez-Rebolledo' (Colección de Sonidos Ambientales IAvH-CSA) at Instituto Humboldt in Colombia, which is one of the most relevant natural sound repositories in South America. The collection was founded in 1998 as 'Banco de Sonidos Animales (BSA)' to document Colombian biodiversity and guide conservation actions, two aims that remain at the forefront of our daily work. After over 25 years, the collection has preserved more than 25,000 audio specimens from over 1,300 species. Here, we highlight the value of sound collections by presenting a historical overview of our collection and providing examples of its role in research and outreach. We also identify taxonomic and geographical gaps that need to be filled, analyse the impact of new technological advances on sound collections, and discuss the critical role of acoustics in the future of research and biodiversity conservation programmes.