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  2. Siren (alarm) - Wikipedia

    en.wikipedia.org/wiki/Siren_(alarm)

    Many fire horn systems were wired to fire pull boxes that were located around a town, and this would "blast out" a code in respect to that box's location. For example, pull box number 233, when pulled, would trigger the fire horn to sound two blasts, followed by a pause, followed by three blasts, followed by a pause, followed by three more blasts.

  3. Warning system - Wikipedia

    en.wikipedia.org/wiki/Warning_system

    There are 8,200 alarm sirens for civil protection throughout Switzerland. They are tested once a year, on the first Wednesday in February. [1] Sound sample ⓘ Warning light indicating danger of laser exposure. A warning system is any system of biological or technical nature deployed by an individual or group to inform of a future danger. Its ...

  4. Q2B - Wikipedia

    en.wikipedia.org/wiki/Q2B

    This Q2B or "Q-siren" is mounted on a Pierce Platform Aerial Fire Truck owned by the City of Bellingham, WA. The Q2B siren (" Q-siren ") [ 1 ] is an electromechanical siren that is produced by the Federal Signal Corporation and is most recognizable for its sound, which is trademarked , and the look of the siren.

  5. Fire alarm notification appliance - Wikipedia

    en.wikipedia.org/wiki/Fire_alarm_notification...

    The standard fire alarm sound used in most of North America [citation needed]. Coding refers to the pattern or tones a notification appliance sounds in and is controlled either by the panel or by setting jumpers or DIP switches on the notification appliances. The majority of audible notification appliances installed prior to 1996 produced a ...

  6. Fire alarm system - Wikipedia

    en.wikipedia.org/wiki/Fire_alarm_system

    Most fire alarm systems in Europe sound like a siren with alternating frequencies. Fire alarm electronic devices are known as horns in the United States and Canada and can be continuous or set to different codes. Fire alarm warning devices can also be set to different volume levels.

  7. List of unexplained sounds - Wikipedia

    en.wikipedia.org/wiki/List_of_unexplained_sounds

    The following is a list of unidentified, or formerly unidentified, sounds. All of the NOAA sound files in this article have been sped up by at least a factor of 16 to increase intelligibility by condensing them and raising the frequency from infrasound to a more audible and reproducible range.

  8. Emergency population warning - Wikipedia

    en.wikipedia.org/wiki/Emergency_population_warning

    It consists in a modulated sound going up and down (up to 380 Hz) during the first minute, and repeated three times. The end of alert is a continuous signal lasting 30 seconds. The system is tested the first Wednesday of every month at 11.45 in the north, 12.00 in the center, and at 12.15 in the south; for tests, the modulated signal is played ...

  9. PASS device - Wikipedia

    en.wikipedia.org/wiki/PASS_device

    In the United States, the National Fire Protection Association sets standards for PASS devices in NFPA 1982. [ 1 ] The PASS device is normally used in conjunction with breathing apparatus; it is a small, battery-powered device attached to the self-contained breathing apparatus (SCBA) harness which enables the firefighter to summon help by ...