Donna Kennedy, age 11, of Englewood, Fla., for her question:
HOW IS SOUND PUT ON MOVIE FILM?
A few motion pictures used sound before 1900 but they depended on hookups with phonographs. Then during the 1920s) Bell Telephone developed a system that combined and coordinated sound on records with the projector. The era of silent films ended in 1927, however, when Warner Bros. studio was able to let A1 Jolson speak and sing in a movie called "The Jazz Singer."
Sound motion pictures were quickly accepted by public as soon as they were introduced. Yearly movie attendance in the United States was 60 million in 1927. But with sound added to the films, attendance increased to more than 110 million persons in 1929.
The first sound system was called Movietone. Sound was photographed directly on the film rather than put on a phonograph record.
In the early days, many silent film stars had voices unsuited to sound pictures.
When you watch a motion picture today, you hear music, dialogue and other sounds that are recorded along one side of the motion picture film called the sound track. The sound track is a composite of dozens of separate sound tracks.
Individual tapes are recorded for a movie's dialogue, for its backgground music and for all special sounds such as boat whistles, forest fires or crowd noises. All of the individual sound tracks are then blended together through a complicated process called dubbing and the result is the composite sound track we hear in the movie.
Dubbing requires a delicate balance of combining the various sounds. They must be properly mixed so that none overpowers the others.
Dubbing is handled in a small projection room after a film's editing is almost complete. Technicians sit behind a sound console and face a viewing screen. Each technician is responsible for certain sounds.
Following a special script, the producer, director and sound technicians then control the fading in and out of the various sounds. All the sounds for each scene in the movie are thus blended into a master tape.
If all of the sounds are not balanced perfectly, the tape is erased and the dubbing is repeated until all are satisfied. When all sound elements are correct, the master tape is used to produce the movie's composite sound track.
In composing music for a motion picture, the score must follow a second by second breakdown of the action. The composer must note where significant action occurs, where dialogue begins and where other important sounds are heard.
After many weeks of writing and long hours of rehearsal with an orchestra, the music is finally recorded with the conductor watching the film so he can match the music with the action.