Well, actually you’ve asked a surprisingly complicated question. Sound didn’t just suddenly appear with the production of one film, and the line between the “silent–era” and the “sound–era” is blurry at best. As Donald Crafton points out in his book, “The Talkies”, sound did not arrive in Hollywood all at once like an express train. “Metaphorically speaking it came gradually, in little crates ‘on approval’, and some left the factory but never arrived at their destination.”
We know that Thomas Edison, perhaps as early as 1893, experimented with using a phonograph record to synchronize sounds with his kinetoscope films, and during the first 30 years of motion picture history there were a great many other experiments with synchronized sound. For instance, D.W. Griffith’s 1921 film “Dream Street” was intended to be screened with a portion of disc–recorded music, but the synchronized sequence was quickly abandoned because of poor synchronization and inferior sound reproduction.
The most successful method for supplying sound–on–disk (where a pre–recorded disk was mechanically synchronized to a film as it was being shown) was the Vitaphone system developed by the Western Electric Company and purchased by Warner Bros. When Warner Bros., who would become the talking–picture pioneers, first thought of utilizing sound they initially saw it as a gimmick to spice up silent film programs, and then as a money–saving (and union–busting) alternative to the pit orchestra in small towns.
On August 6, 1926, Warner Bros. released “Don Juan” starring John Barrymore and Montague Love. “Don Juan” used the Vitaphone sound–on–disk system to synchronize music with the film. The first commercial feature film to have actual synchronized dialogue was the Warner Bros. movie “The Jazz Singer” starring Al Jolson. “The Jazz Singer” was released on October 6, 1927, and it contained both silent scenes and sound sequences (consisting of both synchronized singing and synchronized dialogue). After “The Jazz Singer” proved to be a huge commercial success, it didn’t take long for the other Hollywood studios to convert their production facilities so that they could also make “talking pictures”. Although the awkward Vitaphone system was rather quickly replaced by optical–soundtrack technology (where the soundtrack was placed directly on the film) most people date Hollywood’s official transformation to sound films to that 1927 release of “The Jazz Singer”.
By the way, the following year (1928) Warner Bros. released the first movie to use synchronized dialogue throughout the picture. Advertised as “The First All Talking Picture”, it was a low–budget gangster film starring Helene Costello and Cullen Landis called “Lights of New York”. Costing only $23,000 to make, the movie brought in over $1 million at the box–office.