During the First World War, thousands of young African men conscripted to fight for France and Britain were captured and held as prisoners of war in Germany, where their stories and songs were recorded and archived by German linguists. In Knowing by Ear, Anette Hoffmann demonstrates that listening to these acoustic recordings as historical sources, rather than linguistic samples, opens up possibilities for new historical perspectives and the formation of alternate archival practices and knowledge production. She foregrounds their archival presence as individual speakers and positions their recorded voices as responses to their experience of colonialism, war, and the journey from Africa to Europe. By engaging with the recordings alongside written sources, photographs, and artworks depicting the speakers, Hoffmann personalizes speakers from present-day Senegal, Somalia, Togo, and Congo. Knowing by Ear includes transcriptions of and audio links to specific recordings of spoken and sung texts, revealing acoustic archives as significant yet under-researched sources to recover historical speaking positions of colonized subjects and listen to the acoustic echo of colonial knowledge production.