The Clapper is a sound-activated electrical switch, sold by San Francisco, California based Joseph Enterprises, Inc., Robert E. Clapper, Sr., and Richard J. Pirong and marketed with the slogan "Clap On!" and as a separate phrase "Clap Off!". The Clapper works with any American standard electrical outlet. Although meant to activate by clapping, The Clapper can inadvertently be triggered by other noises, such as coughing, a dog barking, a cabinet or door being closed, laughter, yelling, banging, knocking on a door or a wall, other sharp sounds, or noises from televisions and speakers.