Hello buddy, have you ever seen when you were on the road, then you heard such a vehicle with a loud sound like “ninu ninu ninu” then spontaneuosly people around you moved aside to give it a way?  Yes, the vehicle is using a police siren to alert the person that there is a serious situation.

What is police siren ? And who can use it?

Siren is like an alarm that a loud and making device to warn a natural disasters or alert the people that there is a serious situation . Sirens are used on emergency service vehicle such as ambulances, police cars and fire trucks. read more