Radio documentary is a spoken word radio format devoted to non-fiction narrative. It is broadcast on radio as well as distributed through media such as tape, CD, and podcast. A radio documentary covers a topic in depth through one or more perspectives, often featuring interviews, commentary, and sound pictures. A feature can include original music compositions and creative sound design or can resemble traditional journalistic radio reporting, but cover an issue in greater depth. Current notable examples of this format include work by The Kitchen Sisters and non-fiction segments on This American Life.
The early stages of non-fiction audio storytelling did not entirely resemble what would later be called radio documentary. In the 1930s, with radio stations like WYNC entering the airspace, reporters documented real people and real life scenarios through short on-the-ground interviews rather than dramatization. Other notable documentary broadcasts include the unrefined one-shot audio recordings of events, such as the Hindenburg disaster in 1937. By 1939, CBS responded to growing anxieties about immigration in the U.S. with a six-month series, titled "Americans All…Immigrants All," that highlighted the stories of immigrant communities.
The lack of documentary style reporting in this era can be attributed, in part, to technological limitations; recording equipment was not easily portable.
An important moment in the establishment of radio documentary as a widely used and discussed format is the expansion of portable audio recording devices. In 1945, sound archivist and radio producer, Tony Schwartz began to use portable audio recording equipment to collect the sounds of his neighborhood in New York City to share on his WNYC radio show; his features ran for 30 years and grew to include the sounds of daily life recorded by and mailed to him from people around the world. This style of sharing true-life sound bytes would remain in public radio documentary.
In 1946, one of the most pivotal developments in the spread and stylization of radio documentary was the creation of the CBS Documentary Unit. It was the first sector of a major media network dedicated to this format of radio. The unit was "'devoted exclusively to the production of programs dealing with major domestic and international issues and involving extraordinary research and preparation'". Not only did the content deviate from programming that favors advertisers, the style deviated from the standard, creating a well known format. The style of reporting for the CBS features was adopted and melded by ABC and NBC networks. The format included extensive interviews to gain multiple perspectives of an issue, an adherence to journalistic ethics, and often a call to action; the programming was usually released as multiple segments and at peak times. Examples of these first documentary projects include CBS' 1946 war feature, The Empty Noose, and ABC's 1949 program, V.D., A Conspiracy of Silence, addressing the lack of public attention to venereal disease.