I cannot tell you if the use of sirens in your community are excessive. I know there are sirens where the sound level can be adjusted, but that may not be affordable for your community. Usually, the sirens are necessary. They can be overused. Back in my newspaper reporting days in a small town. I found the night shift at the fire dept. using the sirens to go to and from a grocery store, since no one wanted to cook. That soon came to an end. In my current city, a volunteer fire dept. for an outlying area has a Christmas parade that goes on forever with excessive use of sirens. That kind of noise pollution should be reduced. Response to true emergency situations, require the sirens so people will get out of the way.
I would be grateful in people would not play their radios excessively loud with the car windows down and if certain restaurants would lower the music so I could hear the person sitting across the table. There are all kinds of noise pollution. Some of it we have to accept as necessary. Some is just excessive. I can understand your concern, but can offer no real solution.