Signals, signs, symbols, and gestures may be found in every known culture. the basic function of a signal is to impinge upon the environment in such a way that it attracts attention, as, for example, the dots and dashes of a telegraph circuit. Coded to refer to speech, the potential for communication is very great. While less adaptable to the codification of words, signs contain greather meaning in and of themselves. A stop sign or a barber pole conveys meaning quickly and conveniently Symbols are more difficult to describe than either signals or signs because of their intricate relationship with the receiver's cultural perceptions. In some cultures, applauding in a theater provides performers with an auditory symol of approval. Gestures such as waving and handshaking also communicate certain cultural messager.