Professional audio, also ' pro audio' , refers to both an activity and a type of audio equipment. Typically it encompasses the production or reproduction of sound for an audience, by individuals who do such work as an occupation, using equipment designed for the purpose. ( By contrast, consumer audio is usually confined to the reproduction of sound in the home.) Professional audio can include but is not limited to broadcasting radio, audio mastering, sound reinforcement such as a concert, DJ performances, Audio sampling, public address, surround sound movie theatres, and in some cases piped music application.