Fire alarms are a standard safety sound in buildings around the world, designed to be loud, repetitive and impossible to ignore during an evacuation. Recordings of that siren have become a staple sound effect online because listeners recognise it instantly, without any explanation. Creators use it to signal emergencies, fake evacuations, school drills and over-the-top panic, often pairing the alarm with flashing lights or a sudden cut. Its familiarity is the point: one burst tells the audience something urgent, or hilariously out of control, is happening.