The siren?history and applications

Posted by tedmark on April 10th, 2013

 The siren’s main purpose is to warn people of nearing or imminent danger. They vary in size and scope; from personal alarm systems designed for protection, to home alarm systems, to industrial or government-used alarm systems. Emergency vehicles are perhaps best known for their use of sirens, alerting other drivers on the road that they must yield the right of way. Ambulances, police cars and fire trucks use lights in conjecture with the siren systems, so as to emphasize the urgency of their assignments. Sirens have helped save millions of lives over the years since they’ve been in use, and technological advancements indicate that they will become even more effective, and help save even more innocent lives on the brink of disaster.

Loud sounds have been used as warning devices since the coming of age of man—distressing sounds get a clear message to people, so the more annoying they are, the better they succeed in their role to warn individuals. It will come as a shock to many, thus, to learn that the siren was first invented as a musical instrument, by one John Robinson in 1799. More specifically Robinson used sirens to power pipes in an organ. While early sirens were powered by external sources of compressed air, once commercial electric power became widely available, sirens came to be powered by electric motor, which used a simple centrifugal fan to generate the necessary flow of air.

The civil defense siren is most commonly referred to as air raid siren, because it was initially designed to warn people about air raids during World War II. Civil defense sirens have since been adapted to warn people of natural phenomena (such as tornadoes and earthquakes), or of nuclear attacks. The air raid siren is perhaps best known for first sounding the warnings in London, in September 1939. Air raid siren systems became a regular, even daily part of people’s life in 1940 in London, during the height of the Blitz. For a “Red Warning” of impending danger, the air raid siren produces once single continuous tone, which rose and fell between a high and low tone. When people heard the air raid siren they would know to stop anything they were doing and take cover immediately, and thousands of lives were saved thanks to this type of siren system.

Today, siren systems are used in a variety of applications, with a wide scope. You can purchase a personal alarm system, a mini-siren, so to speak, for the purposes of self-protection. If you find yourself walking along and facing some sort of danger, using a personal alarm system will alert passers-by of your distress, and might even discourage any possible attackers. Home alarm systems are also available for purchase. They combine external and internal sensors, and the noises they produce are extremely customizable. If you have a good sense of humor, try setting the sound of your home alarm system to aggressive dog barks, and see the funny results.

Since its creation, the siren has helped save countless lives. The civil defense siren, also known as the air raid siren is used to warn people of imminent dangers, whether from natural phenomena, nuclear or military attacks.