linguistic:voice_change, linguistic:paraphrasing, structural:summarization
Sound

Citizen Kane ' s sound was recorded by Bailey Fesler and re-recorded in post-production by audio engineer James G. Stewart, both of whom had worked in radio. Stewart said that Hollywood films never deviated from a basic pattern of how sound could be recorded or used, but with Welles "deviation from the pattern was possible because he demanded it." Although the film is known for its complex soundtrack, much of the audio is heard as it was recorded by Fesler and without manipulation.

Welles used techniques from radio like overlapping dialogue. The scene in which characters sing "Oh, Mr. Kane" was especially complicated and required mixing several soundtracks together. He also used different "sound perspectives" to create the illusion of distances, such as in scenes at Xanadu where characters speak to each other at far distances. Welles experimented with sound in post-production, creating audio montages, and chose to create all of the sound effects for the film instead of using RKO's library of sound effects.

Welles used an aural technique from radio called the "lightning-mix". Welles used this technique to link complex montage sequences via a series of related sounds or phrases. For example, Kane grows from a child into a young man in just two shots. As Thatcher hands eight-year-old Kane a sled and wishes him a Merry Christmas, the sequence suddenly jumps to a shot of Thatcher fifteen years later, completing the sentence he began in both the previous shot and the chronological past. Other radio techniques include using a number of voices, each saying a sentence or sometimes merely a fragment of a sentence, and splicing the dialogue together in quick succession, such as the projection room scene. The film's sound cost $16,996, but was originally budgeted at $7,288.

Film critic and director François Truffaut wrote that "Before Kane, nobody in Hollywood knew how to set music properly in movies. Kane was the first, in fact the only, great film that uses radio techniques.... A lot of filmmakers know enough to follow Auguste Renoir 's advice to fill the eyes with images at all costs, but only Orson Welles understood that the sound track had to be filled in the same way." Cedric Belfrage of The Clipper wrote "of all of the delectable flavours that linger on the palate after seeing Kane, the use of sound is the strongest."