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.
Sound film
The development of commercial sound cinema had proceeded in fits and starts before "The Jazz Singer", and the film's success did not change things overnight. Not until May 1928 did the group of four big studios (PDC had dropped out of the alliance), along with United Artists and others, sign with ERPI for conversion of production facilities and theaters for sound film. Initially, all ERPI-wired theaters were made Vitaphone-compatible; most were equipped to project Movietone reels as well. However, even with access to both technologies, most of the Hollywood companies remained slow to produce talking features of their own. No studio besides Warner Bros. released even a part-talking feature until the low-budget-oriented Film Booking Offices of America (FBO) premiered "The Perfect Crime" on June 17, 1928, eight months after "The Jazz Singer". FBO had come under the effective control of a Western Electric competitor, General Electric's RCA division, which was looking to market its new sound-on-film system, Photophone. Unlike Fox-Case's Movietone and De Forest's Phonofilm, which were variable-density systems, Photophone was a variable-area system—a refinement in the way the audio signal was inscribed on film that would ultimately become the standard. (In both sorts of systems, a specially-designed lamp, whose exposure to the film is determined by the audio input, is used to record sound photographically as a series of minuscule lines. In a variable-density process, the lines are of varying darkness; in a variable-area process, the lines are of varying width.) By October, the FBO-RCA alliance would lead to the creation of Hollywood's newest major studio, RKO Pictures.