Phonofilm

PhonofilmDe Forest Phonofilm crew on the grounds of the White House, Washington, D.C., 1924.

Phonofilm, system used in the 1920s to provide sound synchronized with motion pictures. A sound track was photographically recorded on the film by a beam of light modulated by the sound waves. The sound was reproduced during projection by directing a beam of light through the sound track onto a photocell, the response of which was electronically amplified.

This article was most recently revised and updated by Amy Tikkanen.
Citation Information
Article Title: Phonofilm
Website Name: Encyclopaedia Britannica
Publisher: Encyclopaedia Britannica, Inc.
Date Published: 27 September 2013
Access Date: February 22, 2025