What you should know about Police Siren and their Uses

The main factor distinguishing police cars from others on the road is the audio and visual signals installed in them. Of the two, sirens are more effective as they can be heard much before the arrival of the vehicle at the scene of an incident. These sirens are either mechanical or electronic devices. The type that can be installed on police cars are strictly mandated by law in the USA and any deviation leads to strict fines and penalties. 
Police sirens have evolved greatly over time and before you buy police siren for car, you should know more about its intricacies. The early versions of police sirens were mechanical devices that required a lot of maintenance and were not very reliable. Now, electronic sirens are used that have to be simply plugged into the car’s power unit. Various pitches and frequencies can be generated from this one device through in-built oscillators, modulators, and amplifiers. The options before a police officer are sounds ranging from a yelp to wail, hi-lo and pierce/priority.

These sounds are used in specific situations. For instance, the piercing wail or yelp siren is switched on when a police vehicle is traveling at high speed and the road before it has to be cleared. The warble, air-horn, whoop or piercer is usually activated for getting the attention of people and pedestrians. It is thus not difficult to understand the intention of the police car by hearing the type of sound emitted from the siren box.

Incidentally, the first electronic siren that replaced the mechanical devices was invented in 1965 by Motorola employees Ronald H. Chapman and Charles W. Stevens.     


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