query: When was sound introduced to film?
passage: 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.
passage: Silent film
Although attempts to create sync-sound motion pictures go back to the Edison lab in 1896, only from the early 1920s were the basic technologies such as vacuum tube amplifiers and high-quality loudspeakers available. The next few years saw a race to design, implement, and market several rival sound-on-disc and sound-on-film sound formats, such as Photokinema (1921), Phonofilm (1923), Vitaphone (1926), Fox Movietone (1927) and RCA Photophone (1928).