Small mercy: fewer car alarms

As I was cycling home from work this evening, it struck me that my aural landscape is nowadays much less polluted by car alarms than it seems to have been 5 to 10 years ago. I don't think there are fewer cars, and I doubt the percentage of cars with car alarms has done anything but increase, so I wonder how this is possible. Are the alarm sirens now less obnoxious than they used to be? Are thieves better at stealing cars without setting off the alarms? Is it just that I've been living in a nicer and quieter neighbourhood post-2005 than pre-2005? Have I become less attuned to them? Whatever the reasons, I'm glad for this small mercy.