Boards
Sirens
When I was a kid I could tell the difference between fire engines, police cars and ambulances by their siren. Like, I could tell you what was coming before I saw them.
Fire engine was the easiest, nee naw nee naw nee naw. Police car is weeeeaaooowwwweeeeeooaaaaww, that one. Ambulance is wowowowowow.
Nowadays it seems as though the last two are interchangeable. Just seen an ambulance and it did both, and then that excellent deafening white noise one. Fire engines keep it classic, nee naw all day long.
Sirens eh