However, these early attempts were made by theater owners, and not part of the films themselves, and thus were seen as an offense to film aesthetics, as the audience could be distracted by the scents instead of focusing on what the film director intended. Furthermore, because of the size of the theaters, large amounts of perfume had to be released in order to reach all members of the audience. This caused another problem: The human nose has a difficult time transitioning between smells until the molecules that triggered one smell are completely cleared from the nose, and with that volume of perfume, the scents would mix together, becoming muddled.
Laube's technique, which he dubbed "Scentovision", was to connect pipes to individual seats in theaters, so that the timing and amount could be carefully controlled by the projectionist using a control board. He introduced this system in the 1939 New York World's Fair. The New York Times reported in 1943 that Scentovision "is said to have produced odors as quickly and easily as the soundtrack of a film produces sound."
Laube's system, which was renamed "Smell-O-Vision" by Todd, had been improved in the intervening time. Now, instead of the scents being manually released, it used what he called a "smell brain", which was a series of perfume containers linked in a belt, arranged in the order that they would be released. The belt was then wound around a motorized reel. As the film threaded through the movie projector, markers on it would cue the brain. Needles would pierce membranes on the containers, releasing the scents, which would then be blown by fans through the pipes to individual vents underneath the audience members' seats.
Both Laube and Todd understood that the system had aesthetic limitations. For example, a heavy drama was not the sort of film that could employ it well. Thus, the system was to be deployed with the mystery-comedy Scent of Mystery, which would be the first film in which smells revealed certain plot points to the audience. For example, one character is identified by the smell of pipe tobacco.
Unfortunately, it didn't work as intended. According to Variety, aromas were released with a distracting hissing noise and audience members in the balcony complained that the scents reached them several seconds after the action was shown on the screen. In other parts of the theater, the odors were too faint, causing audience members to sniff loudly in an attempt to catch the scent. These technical problems, in conjunction with generally negative reviews of the film itself, signaled the end of Smell-O-Vision.
In homage to Smell-O-Vision, American film director John Waters released an enhanced "Odorama" version of his film, Polyester in 1982. Waters included scratch and sniff cards that the audience could use while watching the movie. Although this approach solved the problems inherent in previous attempts at this technology, it did not gain widespread usage for other films. The idea, however, was duplicated twice: Once in the mid-1980s when MTV aired Scent of Mystery in conjunction with a convenience store promotion that offered scratch and sniff cards; the second time was the 2003 animated film Rugrats Go Wild!, the makers of which claimed it was an homage to Waters.
The Walt Disney World and Disneyland Resorts currently make use of this idea, in their 3-D films and other attractions. The Animal Kingdom's attraction It's Tough to Be a Bug (also at Disney's California Adventure) releases an unpleasant odor coinciding with a stink bug on-screen, causing an audience reaction, similarly Mickey's Philharmagic at the Magic Kingdom in Orlando produces pie scents. Soarin' Over California and Soarin' include orange blossom, pine forest, and sea air fragrances as the scenery flies below the passengers. Heimlich's Chew Chew Train drips watermelon scented water onto the riders before crawling through an Animal cracker scented box. Monsters, Inc. Mike & Sulley to the Rescue! briefly takes riders through a ginger scented sushi house. It is unknown, however, if the technology behind this is the same or a derivative of Laube's work.
In 2006, NTT Communications, a Japanese telecom giant, developed a new way to display odors during the release of Terrence Malick's The New World. During 7 key moments throughout the film, scents were emitted by an internet server that was linked to the reel of film, effectively downloading the scent. The schedule can be seen here: The scents used were supposed to evoke from the audience the emotions that were trying to be expressed in the film. Further reading of how it this system works can be seen here: including an illustrated schematic for a visual representation for how it worked. Scents included: floral for romance scenes,peppermint & rosemary for tear-jerking moments,orange & grapefruit for joyful sequences, and eucalyptus, tea tree & herbs for angry scenes.
In 1965, BBC TV played an April Fool's Day joke on their viewers. The network aired an "interview" with a man who had invented a new technology called "Smellovision" that allowed viewers at home to experience aromas produced in the television studio. To demonstrate, the man chopped some onions and brewed a pot of coffee. Viewers called in to confirm that they had smelled the aromas that were "transmitted" through their television sets.
On the animated sitcom Futurama, which takes place 1000 years in the future, Smell-O-Vision has successfully taken off. Harold Zoid, a washed up movie director, comments he flopped after they invented "Smell-O-Vision".