Network public address, also known as public broadcasting services or public media, refers to the non-profit electronic media established and operated by government budgets or public funds. This kind of media makes and broadcasts programs mostly on the basis of the discussion of public policy, the art of culture and education, or the knowledge. The purpose of these media is to improve the knowledge level of the nation and promote public participation in political decision-making. In general, the news media that is not controlled by the non-democratic government is called public media. Although the television stations of this kind are also supported by the government's funds, these media are generally lacking in the independence of editing and operation, and the independence of the broadcast content and operation is an important symbol of the public media.
The public address system is a systematic project. It is a combination of various disciplines such as electronic technology, electroacoustic technology, sound building technology, acoustic art, etc. The sound effect of the public address system is not only related to the comprehensive performance of the electroacoustic system but also closely related to the sound transmission environment architectural acoustics and live tuning. The final effect of a public address system is determined by the best cooperation between the correct and reasonable design and debugging of the electrical sound system, the good sound transmission conditions, and the correct live tuning technology, the three are supplementary to each other and indispensable. In the system design, the above aspects must be taken into consideration. On the basis of the sound electrical equipment with good performance, the sound and natural sound effects of electroacoustic sound can be achieved through careful system design and debug, and good sound building conditions.