Many people are not familiar with the "sounding of the sirens" in rural towns. It has actually evolved through the years from the civil defense sirens of the 1960s to weather warning sirens and city-wide fire alarms today.
Every Wednesday at noon, there is a test siren from the local fire/police dispatch center. It is a systems test to make sure it works in a real-time emergency. The long, continuous sound is used there is an impending tornado in our immediate area.
At other times when you hear the siren sound that raises and lowers continuously for a minute or so, it is a fire alert warning. It is for local fireman, informing them of a need for fire service activation. They do have individual equipment and the siren is a backup system but can also alert citizens that approaching emergency vehicles are a possibility.
Certainly, no emergency warning system is perfect; however, in certain circumstances it could be lifesaving. So, know your local warning systems and be familiar with their sounds.