Terrifying Air Raid Siren Sound In USA ☢️🔊🇺🇸 A civil defense siren is a siren used to provide an emergency population warning to the general population of approaching danger. Initially designed to warn city dwellers of air raids (air-raid sirens) during World War II, they were later used to warn of nuclear attack and natural disasters, such as tornadoes (tornado sirens). The generalized nature of sirens led to many of them being replaced with more specific warnings, such as the broadcast-based Emergency Alert System and the Cell Broadcast-based Wireless Emergency Alerts and EU-Alert mobile technologies. By use of varying tones or binary patterns of sound, different alert conditions can be called. Electronic sirens can transmit voice announcements in addition to alert tone signals. Siren systems may be electronically controlled and integrated into other warning systems. Sirens are sometimes integrated into a warning system that links sirens with other warning media, such as the radio and TV Emergency Alert System, NOAA Weather Radio, telephone alerting systems, Reverse 911, Cable Override, and wireless alerting systems in the United States and the National Public Alerting System, Alert Ready, in Canada. This fluid approach enhances the credibility of warnings and reduces the risk of assumed false alarms by corroborating warning messages through multiple forms of media. The Common Alerting Protocol is a technical standard for this sort of multi-system integration.[2] Siren installations have many ways of being activated. Commonly used methods are dual-tone multi-frequency signaling (DTMF) or public switched telephone network (PSTN) using telephone lines, but activation can also be done via radio broadcast. This method opens up vulnerability for exploitation, but there are protections from false alarms. These sirens can also be tied into other networks such as a fire department's volunteer notification/paging system. The basics of this type of installation would consist of a device (possibly the same pager the firefighters have) connected to the controller/timer system of the siren. When a page is received, the siren is activated. In the United States, several sets of warning tones have been used that have varied due to age, government structure, and manufacturer. The initial alerts used during World War II were the alert signal (a 3–5-minute steady, continuous siren tone) and the attack signal (a 3–5-minute warbling tone, or series of short tone bursts on devices incapable of warbling, such as whistles). In 1950, the Federal Civil Defense Administration revised the signals, naming the alert signal red alert and adding an all clear signal, characterized by three one-minute steady blasts with two minutes of silence between the blasts. In the United States, there is no national level alert system. Normally, sirens are controlled on a county or local level, but some are controlled on a state level, such as in Hawaii. Sirens are usually used to warn of impending natural disaster; while they are also used to warn of threats of military attacks, these rarely occur in the United States. Throughout the Great Plains, Midwest, and South, they are typically used to warn the public to take cover when a tornado warning is issued, sometimes even for severe thunderstorm warnings, and very rarely used for anything else. They are generally required in areas within a ten-mile radius of nuclear power plants. In the South and on the East Coast (except for Texas, Maine, Florida and New Hampshire), sirens are used to inform people about approaching hurricanes. Coastal communities, especially those in northern California, Oregon, Washington, Alaska, and Hawaii, use siren systems to warn of incoming tsunamis. In 2011, the city of Honolulu created an Adopt-a-Siren website for its tsunami sirens. The site is modeled after Code for America's Adopt-a-Hydrant, which helps volunteers in Boston sign up to shovel out fire hydrants after storms. #terrifyingairraidsiren #terrific #air #raid #siren #airraidsiren #airsiren #airraidsirensound #airraidsirensoundeffect #cityairsiren #loudsiren #worldwar #unitedstates #america #sirensoundeffect #loudsirensound #cityalarm #citysirensound #citysiren #worldwarsiren #sirensoundeffectdownload #warningsiren #warningsoundeffect #trending #viral #usa #uk #germany #australia #canada #unitedstatesofamerica #unitedkingdom terrific air raid siren sound | city air siren sound | air siren sound effects | air raid siren sound effects | city siren alarm | city warning siren | loud siren sound effect | air raid siren sound effect free download | city siren sound effect free download | world war siren | free download sound effects | world war siren sound | warning siren | warning siren sound effect | united states of america | united kingdom | germany | australia