The emergency evacuation sirens are an indication of an emergency. When you hear this siren, you leave whatever you are doing and carefully make your way to the exit route. In condos, factories, schools, and other types of dwelling, these sirens are a mandatory requirement. A failure to put the evacuation sirens can result in penalization by the legal administration.
There are specific protocols to follow when the emergency evacuation sirens go off. Almost all places hold mock drills where they put a situation of a fire hazard, earthquake, or any other simulation. Through these mock drills, they check the evacuation sirens and also educate the people on how to react when they hear the siren. These systems are life-saving instruments, so it comes as no surprise that they are in place in all types of working and residential buildings.