Phonofilm is a sound-on-film system developed by inventor Lee DeForest in the 1920s.
Read more about Phonofilm: Introduction, Premiere of Phonofilm, Development of Phonofilm, DeForest's Use of Case Patents, Producer Pat Powers Attempts Takeover of Phonofilm, Hollywood Chooses Other Sound Systems, Phonofilm in The UK, Phonofilm in Australia, Phonofilm in Spain, Phonofilm in Latin America, Legacy of Phonofilm, List of Films Produced in Phonofilm, See Also