A clap is the sound made by striking together two flat surfaces, as in the body parts of humans or animals. Humans clap with the palms of their hands, often in a constant drone to express appreciation or approval (see applause), but also in rhythm to match sounds in music and dance. Seals are among the animals that clap. Some people slap the back of one hand into the palm of the other hand to signify urgency or enthusiasm; others consider it uncouth. Perhaps the best-known koan involves (at least superficially) consideration of the act of clapping: "What is the sound of one hand clapping?" Clapping is occasionally used as a percussion element in music, particularly in Gospel music. One composition by Steve Reich, Clapping Music, is entirely performed by clapping. The clapping patterns known as keplok are important in Javanese gamelan. Pedagogical applications Music students often clap the rhythm of written music to help learn the value of different notes and to get accustomed to the rhythm of new pieces. A book that is often used to demonstrate this is Rhythmic Training by Robert Starer. [edit] Acoustics applications Clapping can be used in acoustics to check the reverberation time of a room. The clap's decay time determines this. Pretty much any sound can be used to do this but a sound of a hand clap delivers a clear sound of short length and is readily available. [edit] Medical applications Inhalation therapists frequently use clapping (light slaps with a cupped hand on a patient's back, chest, and under arms) to dislodge mucus from breathing passages in order to improve airflow. Hope I Helped!

Generally, an audience will clap rhythmically in unison, about two claps per second, to indicate approval. When this rate is slowed down considerably and becomes synchronised throughout the audience participants, in many cultures this is considered an expression of mocking dislike or disapproval of the performer, and is termed a slow handclap. The person being slowly clapped at may interpret the clap as an insult and a sign to leave the stage. During musical events, however, it is common for an audience to clap in the rhythm of the song, to cheer the artists present on stage. A notable occurrence of a slow handclap took place during a speech made by British Prime Minister Tony Blair on 7 June 2000, when he was heckled and slow-handclapped by members of the Women's Institute. Hope I Helped Again!

In the deaf community instead of clapping their hands they hold both hands up , (approximately level with their head), fingers spread out, and rotate their wrists forward and then back VERY quickly. It looks similar to "jazz hands".