Sound film
The primary steps in the commercialization of sound cinema were taken in the mid- to late 1920s. At first, the sound films which included synchronized dialogue, known as "talking pictures", or "talkies", were exclusively shorts. The earliest feature-length movies with recorded sound included only music and effects. The first feature film originally presented as a talkie was "The Jazz Singer", released in October 1927. A major hit, it was made with Vitaphone, which was at the time the leading brand of sound-on-disc technology. Sound-on-film, however, would soon become the standard for talking pictures.
Live event support
In 1935, 16 mm Kodachrome film projectors added the first fully animated visual reinforcement to live events.A sound reinforcement system is professional audio, was first developed for movie theatres in 1927 when the first ever talking picture was released, called "The Jazz Singer". Movie theatre sound was greatly improved in 1937 when the Shearer Horn system debuted. One of the first large-scale outdoor public address systems was at 1939 New York World's Fair.