Throughout its long history, theology has debated the application of the word of God—its “scientific object”—to the human world. While some argued that any human attempt at such application is fundamentally condemned to fail, others explored speech arts, humanities knowledge, and media practices as means to pursue an applied theology. This lecture examines how German-speaking theologians—whether “applied” or not— engaged with a new mass medium in early radio sermons of the 1920s and 1930s, especially with regard to speech style and acoustic performance.