Police Sirens

Police sirens are more than just noise makers. They’re life savers. They’re crime stoppers. They’re alert systems. And , yes, police sirens make noise.

The word siren comes from Greek mythology where it referred to mermaids who lured sailors to their deaths with their beautiful songs. The siren sound we know today is a warning sign to either stop, go or get out of the way.

The first sirens were developed in the early 19th century using a pneumatic tube and two perforated discs, one of which rotated. The pneumatic tube produced air which flowed to the fixed disc, and as the other disc rotated, it interrupted the airflow through the perforations and created a sound with high and low tones.

Later models feature two slotted, concentrically placed cylinders. One rotates and the other stays still. The spinning cylinder interrupts the airflow to produce the sound.

When electricity was invented, the pneumatic tube was replaced with a fan that was outfitted inside the rotating cylinder to produce the airflow needed to achieve the sound. To make the sound more powerful, manufacturers added a horn that increased the volume of the noise output.

Today’s police sirens come in a variety of models, style, sounds and mounting options. There are even siren options available for installation on motorcycles, bicycles and golf carts. For undercover work, there are police sirens that can be mounted in remote locations. Other models, like the Whelen 2955L 100, offer hands-free operation for the ultimate in flexibility. Some sirens, such as the Rumbler, use sound and vibration to alert surrounding pedestrians and motorists that a police vehicle is in the area at a high rate of speed.

Sirens produce a variety of sounds from a yelp or yodel to a wail or a scream, and some even include an air horn to add additional help to clearing an intersection.  No matter what sound they make though, police sirens are an important part of an officer’s duty to protect and serve.