An ambulance siren is a loud, high-pitched sound used by emergency vehicles to alert other road users of their presence. The siren helps clear a path for the ambulance, allowing it to reach patients quickly. Different siren patterns can indicate various situations, such as urgency or the need for immediate attention. The sound of an ambulance siren is designed to be attention-grabbing and can be heard over traffic noise. In many countries, the use of sirens is regulated to ensure they are used appropriately during emergencies, helping to save lives by reducing response times.