This week: Endangered Languages: the various human languages, encompassing sounds ranging from whistling to drums as well as vocal sounds, are significant acts of making. It is estimated that there are between 6,000 and 7,000 languages spoken, and that between 50 and 90% of these will become extinct by 2100. The Endangered Language Archive is a digital repository specialising in preserving and publishing endangered language documentation materials from around the world. Andrew Prescott talks to Mandana Seyfeddinipur of ELAR and Dr John Wynne, Reader in Sound Arts, London College of Communication, about the work of preservation. Endangered sounds will be heard.