public address systems

Examples of other technologies include : Cable Television ( CATV ) Services, Display Systems and Public Address Systems ( PA ).

例如: 有线电视 ( CATV ) 服务 、 显示系统和公共广播系统 ( PA ) 等.

The acoustic feedback problem is a long-standing problem appearing in sound reinforcement systems and public address systems.

在扩声系统及公共广播（Public Address，PA）中，声反馈是一个长期存在的问题。

These developments enable new functionalities in the public address systems for the benefit of railway operators and passengers.

继续发展的这些技术，给旅客信息系统提供了有利于铁路运营部门和旅客的新功能。

public address systems (pa systems) are commonly used in american malls, airports and grocery stores.

公共广播系统在美国的商场、机场、和杂货店普遍使用。