|This article does not cite any references or sources. (February 2012)|
The Clapper is a sound activated electrical switch, sold by San Francisco, California based Joseph Enterprises, Inc and marketed with the slogan "Clap On!" and as a separate phrase "Clap Off!". The Clapper works with any American standard electrical outlet.
Two upgrades have been made.
- The Smart Clapper allows control of two devices, based on if a person claps two or three times.
- A design revision known as the Clapper Plus includes a remote control function in addition to sound-based activation.
The Clapper can sometimes be triggered by coughing, a dog's bark or clapping that emanates from televisions and stereo speakers set at high volume, making it somewhat inconvenient for households with dogs and loud appliances.
There is also an away setting on the clapper that turns on whatever is plugged into it at any detection of noise. It can also be used to turn lights on whenever a room is occupied without having to clap.
The Clapper, was issued US Patent #5493618 on July 9, 1985 and first sold to the public on September 1, 1986.
The melody of the catchy jingle used in the commercials ("Clap on, clap off...") had been used earlier back in the mid 1980s for Sine-Off cold medicine, in a commercial featuring women at an army base.
In popular culture 
- Prior to the Clapper being marketed, the idea showed up in popular culture. On the 1970s show Nanny and the Professor (S1E2), the Professor's oldest son, Hal, shows off his invention of a sound activated switch that is triggered by him clapping. Coincidentally, the show also goes on to show the problems of the switch with other loud household noises - something the commercial version would also contend with.
- In the 1989 film Uncle Buck, the title character uses The Clapper to turn on the lights in his apartment
- In the pilot episode of Tyler Perry's Meet The Browns, Leroy Brown talked about how he went to a store and asked an employee if the store were selling The Clapper. Brown, however, referred to The Clapper as "The Clap".
- In the 2013 film, The Conjuring (film), Lili Taylor's character is tormented by a clapping ghost which repeatedly turns out the lights.
- In the 2006 film, Night at the Museum, when Larry Daley (Ben Stiller) is at the Job agency presenting his resume, he mentions that he created "The Snapper", and that "The Clapper" stole "a bit of his thunder".
- In the 2003 dark comedy, Duplex, Alex (Ben Stiller) installs the clapper in Mrs. Connelly's TV so that he can turn it off from his apartment below by clapping. One night the two of them go back and forth in a clapping battle, Alex turning her loud TV off, and Mrs. Connelly turning it back on, and back off, and then back on, etc.
- The Clapper appears in Bruce Almighty where God clapped off the lights, then recites "The Clapper" jingle.
- In the 19th episode of The Simpsons´ ninth season, titled "Simpson Tide" originally aired on the Fox network on March 29, 1998, a reference to "The Clapper" is made where Homer tells his wife Marge that "We live in a highly technological age where fighting a war is as simple as turning off a light!" then proceeds to clap with his hands... and the light remains on.. he continues clapping while Marge says "We don't have a clapper" the gag ends with the lamp flying out the window to turn it off.
- In the 1999 comedy Austin Powers: The Spy Who Shagged Me, Austin Powers (Mike Myers) claps twice to activate the "seduction lighting" in his apartment. An impressed Ivana Humpalot (Kristen Johnston) asks "When did you get ze Clapper?". Austin, thinking she means "the clap" replies "Dutch East Indies, shore leave."
- In the Mary-Kate and Ashley Olsen film "Passport to Paris", the twins clap their hands- turning off the lights.
- In The Big Comfy Couch, Loonette and Molly clap their hands twice to turn their big lamp on and off.
- In 9 to 5 the musical, written by Patricia Resnick and music by Dolly Parton, in the finale it is referenced as one of the characters was said to have invented it. The stage appears in a blackout until Dolly Parton, projected to the stage, claps.
- In the Space Quest 6 demo (But not the full game!), Roger Wilco uses a clapper (Or a "ClapMaster" in the case of the game) to defeat the evil Bjorn who have invaded his space ship.