Watch Okay for Sound (1946) : Full Movie Online Free This short was released in connection with the 20th anniversary of Warner Brothers' first exhibition of the Vitaphone sound-on-film process on 6 August 1926. The film highlights Thomas A. Edison and Alexander Graham Bell's efforts that contributed to sound movies and acknowledges the work of Lee De Forest. Brief excerpts from the August 1926 exhibition follow. Clips are then shown from a number of Warner Brothers features, four from the 1920s, the remainder from 1946/47.