The film is a loose adaption of Edgar Allan Poe's "The Raven" but also references "The Tell-Tale Heart" and "Lenore."
The flashback scene was the very last scene for production.
The story had changed dramatically throughout its re-writes. Originally, the film was set in Montauk, Long Island and Allan was a wealthy guilt-ridden widower who was suffering from his wife's suicide (she drowns herself in the ocean). In his guilt, he imagine Lenore haunting him in his study.
One of the biggest influences for the film's sound design was the sound design for the film, Zodiac (2007). Maeda felt the film utilized the radio as an effective way to add tension to the story. Another influence was Raging Bull (1980).
Director, Takeru Maeda, kept the prop raven when production wrapped.