type of signaling device that alerts people to a dangerous condition

An alarm is something used to alert people quickly to something. Most alarms use loud noises and/or flashing lights. Some alarms may use other ways of attracting peoples attention quickly, such as turning off loud machinery, shaking a bed or pillow.

An alarm for warning railway track workers, using a siren and flashing light, in Germany.

Types of alarms

  • Alarm clock - A clock designed to make noise to wake up people.
  • Burglar alarm - An alarm that sounds if a person tries to enter a building without permission.
  • Siren on an emergency vehicle (ambulance, fire truck, police car).
  • Severe weather sirens - Used to warn of severe weather, such as tornadoes or tsunamis.
  • Klaxon - A type of siren, known for it's distinct sound. Often found on submarines.
  • Fire alarm - An alarm for warning of fire inside of a building.