How to distinguish the screams of ambulances, police cars and fire engines?

The fire alarm is slow: low-high-low-high-low.

Early warning of middle police car: low-high-low-high-low.

The ambulance goes up and down: high-low-high-low-high-low-low-low-high-low.

It's just Malik Li San's cross talk, which is quite interesting.

The siren of the fire truck is three seconds long, and it goes back and forth at intervals of one second. As Mr. Ma Lao said: fire ~ ~ ~ fire ~ ~ ~

Ambulances pitch for one second, pitch for one second, interval for one second, and so on. Mr. Ma Lao described it as: alas ~ ~ yo ~ ~ alas ~ ~ yo ~ ~

The siren of the police car is very urgent and there is no interval. Mr. Ma described it in one word: it's over, it's over, it's over. ......