What do the different siren sounds mean?

sounds mean

With their use being adopted all over the United States shortly after world war two, outdoor warning sirens are known for the piercing loud sound they produce. Designed to warn people located outdoors of incoming danger, when heard, they should be taken as an indication to take cover and head indoors towards safety. Sirens work by pushing air stream against a rotating surface which typically contains holes or perforations.

Mechanical sirens utilize these by pushing air streams against said perforated disk causing the airflow to be interrupted and allowed to pass through intermittently, creating a fluctuation that will generate the high pitch sounds we hear. Although similar electrical sirens in contrast, work by relying on the electric motor turning a fan spinning inside a slotted drum, sucking the air from the front and letting it out through the sides. Regardless of type, both sirens create identifiable high-pitched tones which serve as an indication to people who hear them of, the course of action to be taken.

What do they mean and what we should do?

The context you’re in will typically dictate the course of action to be taken when hearing the tone of a siren as, you will usually find yourself located outdoors when hearing one. The general idea is always to head for cover or seek shelter indoors. Multiple tones can be projected with each one having its own respective meaning. There are essentially three types of tones: a fixed intermittent tone, a “wavy” tone and lastly, a fixed continuous tone.

The intermittent or single tone lasts for a fixed amount of time and is used to indicate nearing danger, synonymous with emergency alerts, this tone is commonly used to announce an incoming storm, flood, natural disaster or, emergency. The up and down tone or “wavy” tone, sounds like it’s coming towards and away from you and will also last a fixed amount of time, it’s mostly used to signal incoming or occurring danger and implies an impending attack is looming on the local community. Lastly, you could hear a third type of tone which is continuous, in comparison with the intermittent tone it also lasts a fixed amount of time but, as the name indicates is continuous and is mostly used as an “all clear” signal to indicate danger has passed.

What do the different siren sounds mean?

Used in times of war, emergency and even peace like during instances of industrial or natural disaster for example, being able to identify and know what course of action to follow when exposed to said siren tones is vital. Having this broad understanding can lead to life saving action being taken in a timely manner, often resulting in many lives being saved.

For this reason, many place and institution will choose to incorporate siren test days and times to get individuals acquainted and familiar with the way they operate, work and most importantly, what they mean and what to do upon hearing them.


Amy Rey
the authorAmy Rey

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