1920s

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1920

The first regular radio entertainment broadcasts begin in Buenos Aires.

1923

Lee De Forest's Phonofilm makes the first screening of shorts with optical sound incorporated in the film (the future standard system).

1926

The Vitaphone system is created for adding the sound to films. The first sound films with this system, Don Juan and The Jazz Singer, herald the era of sound films.

1927

Austrian engineer Fritz Pfleumer uses cigarette paper covered with iron oxide powder to record sound, the forerunner of magnetophonic tapes.

1928

Harry Nyquist publishes his theorem on the sampling of an analogue signal that lays the theoretical foundations for the digitization of sound.