Mickey Mouse
Audiences at the time of "Steamboat Willie"'s release were reportedly impressed by the use of sound for comedic purposes. Sound films or "talkies" were still considered innovative. The first feature-length movie with dialogue sequences, "The Jazz Singer" starring Al Jolson, was released on October 6, 1927. Within a year of its success, most United States movie theaters had installed sound film equipment. Walt Disney apparently intended to take advantage of this new trend and, arguably, managed to succeed. Most other cartoon studios were still producing silent products and so were unable to effectively act as competition to Disney. As a result, Mickey would soon become the most prominent animated character of the time. Walt Disney soon worked on adding sound to both "Plane Crazy" and "The Gallopin' Gaucho" (which had originally been silent releases) and their new release added to Mickey's success and popularity. A fourth Mickey short, "The Barn Dance", was also put into production; however, Mickey does not actually speak until "The Karnival Kid" in 1929 when his first spoken words were "Hot dogs, Hot dogs!" After "Steamboat Willie" was released, Mickey became a close competitor to Felix the Cat, and his popularity would grow as he was continuously featured in sound cartoons. By 1929, Felix would lose popularity among theater audiences, and Pat Sullivan decided to produce all future Felix cartoons in sound as a result. Unfortunately, audiences did not respond well to Felix's transition to sound and by 1930, Felix had faded from the screen.
Filmmaking technique of Luis Buñuel
Buñuel has been hailed as a pioneer of the sound film, with "L'Age d'Or" being cited as one of the first innovative uses of sound in French film. Film scholar Linda Williams has pointed out that Buñuel used sounds, including music, as nonsynchronous counterpoint to the visual image, rather than redundant accompaniment, in accordance with theories that had been advanced by Sergei Eisenstein and others in a 1928 manifesto on the sound film. Critic Marsha Kinder has posited that Buñuel's years as a film dubber in Europe and Hollywood put him in the position of "mastering the conventions of film sound, to subvert them more effectively". In his later years, Buñuel was almost completely deaf, but he continued to assert control over the sound effects in his films, such as "The Discreet Charm of the Bourgeoisie", in which seemingly important speech, especially political discourse, is often drowned out by the noise of urban life, in such a systematic manner that Kinder has identified Buñuel as one of the first professional sound designers in cinema. As further illustration of this, scholar Sally Faulkner has described the means by which, in his film "Tristana", Buñuel "engineers a kind of figurative deafness, or disability, in the spectator" in scenes which involve deaf characters, by, for example, combining the sound of gushing water with an image of a stagnant pool, or exaggerating the volume level of chiming bells.