Whenever there are announcements, people would pause for a while and listen. The inherent curiosity among humans causes this kind of reaction. Even animals are very receptive to sounds they are hearing. To be more effective, announcements are done through public address system. For small applications like shops and bars, a Portable pa system will do the job. A centralized system would be too expensive for this purpose.

In the past, a public address system can be very costly because of the very low demand. There are only few establishments and organizations that use the equipment and only those that constantly issue announcements have requirement of the unit. As more affordable technologies are introduced, the pa system has also transformed to be more cost effective. There are now different versions of the device that can be considered by various end users. It would now be easier to convey information to more number of people using more audio systems.