A Public Address System is a set of audio equipment or sound system allowing broadcasts over a certain area. It is a set of equipment that amplifies a sound and distributes the sound to its intended recipients. It is used for announcements or any immediate information that has to be communicated for example in schools, churches and other office buildings. It enables communication to a large scale audience.
Also known as PA system, the simple ones are composed of a basic microphone, an amplifier and a loudspeaker. The equipment is placed and distributed at strategic places of the area where the broadcast is necessary. An amplifier is needed to reinforce the sound level so that it reaches the farthest distance required. In case variation of sound level is needed, a sound mixer solves the problem. The broadcast is basically processed by transmitting the audio source to a sound system through connected cables to the output speakers. The audio source could be a human speaking through a microphone or it may be a digital audio such as CD player or radio connected to the output speakers. Large scale PA systems, which use the same technology but of higher fidelity called hi-fi systems, are used for concerts and other theater activities.
PA systems are chosen depending on the needs of its application. Some of the considerations may the kind of music or speech being played as well as how loud does the output sound needs to be. The area where the sound is to be distributed is also a crucial factor. Public Address systems are used on Australian beaches throughout summer by Life Saving Australia to assist in the safety of swimmers.