Smell-O-Vision was a system that released
odor during the projection of a
film so that the viewer could "
smell" what was happening in the movie. The technique was created by Hans Laube and made its only appearance in the
1960 film
Scent of Mystery, produced by
Mike Todd, Jr., son of
film producer Mike Todd. The process injected 30 odors into a movie theater's seats when triggered by the film's soundtrack.