Ample evidence attests to the emergence of a 'documentary project' in radio by the 1930s, located in multiple sites of creation, many of which developed concurrently, or in dialogue, with the documentary movement in cinema gathering momentum in these same years. Across diverse sites practitioners built bodies of work, some influencing other authors through their ideas, approach or sensibility towards the subjects they chose to explore and reveal. As in the world of film making, a small number of key individuals-auteurs-and centres of production-workshops, studios-helped shape the wider field and offered a vision, as well as encouraging considerable institutional support. Becoming aware of experiments in documentary in cinema, these new radio 'producers' also developed techniques to explore all kinds of subject matter in an array of new forms. They took their microphones and new recording apparatus 'en plein air', gathering the 'acoustic expression of life' to compose a whole new auditory field for documentary creation. More than the "creative treatment of actuality" (Grierson and Hardy 1946: 11), this also included work close to the radio drama. As with cinema, this expansion of the documentary in radio and sound evolved in relation to other arts and literature, and with the rise of another new field: broadcast journalism and reportage. We can encounter a host of new terms employed in the first decades of radio which refer to this emerging international field for documentary; some of these terms also announced a new art form which drew on radio's own distinctive qualities. Here we encounter the 'sound picture', 'actuality', 'acoustic film', 'radio-film' and 'feature'-with terminology in German and Danish ('Hörfolge', 'Hørebilleder', 'Hörfilme',) mirroring some of these terms; in French the 'suite radiophonique', 'mosaïque', and 'film radiophonique' reveals these influences and echoes other media art forms.