Question: When did sound become a regular part of the motion picture viewing experience?
Disambiguated questions and answers: question: When did sound become introduced as part of the motion picture viewing experience?
When did sound become a regular part of the short motion picture viewing experience indicated by the first commercial screening of sound-on-film?
When did sound become a regular part of the motion picture viewing experience indicated by the release of the first feature talkie?
When did sound become a regular part of the motion picture viewing experience indicated by global acceptance?
answer: 1900
14 April to 12 November 1900
Paris Exposition in 1900
April 15, 1923
1923
October 1927
October 6, 1927
early 1930s
1930s
Natural Questions answer: 1929 (from the Wikipedia article "History of film")