95% of car alarm activations are false, each blasts 125 dB for 20-30 minutes, and less than 1% of people who hear one call the police -- yet no U.S. city has banned them

Experts estimate that 94 to 98 percent of car alarm activations are false -- triggered by passing trucks, wind, thunderstorms, a pedestrian brushing the vehicle, or another car's horn. When triggered, a typical car alarm produces 100 to 125 decibels (some models advertise 125 dB as a feature) and sounds continuously for 20 to 30 minutes before auto-resetting, at which point it can be triggered again. A survey by Progressive Insurance found that fewer than 1% of people who hear a car alarm would notify the police. The U.S. Census Bureau reports that noise is Americans' chief complaint about their neighborhoods and the primary reason they wish to move. In New York City, more than 80% of calls to the quality-of-life hotline concern noise, with car alarms representing a significant category. The practical result is an anti-security device: car alarms produce enormous amounts of noise pollution while providing essentially zero theft deterrence. Because nearly everyone ignores them, they do not protect vehicles. But they do wake hundreds of people per activation. A single falsely triggered alarm at 3 AM on a residential street exposes every household within audible range to noise levels that the WHO classifies as immediately harmful. Repeated nighttime awakenings of this kind cause the same cascade of health effects as other chronic noise exposure: elevated cortisol, cardiovascular strain, impaired immune function, and cumulative sleep debt. Residents in dense urban areas may experience multiple false car alarm events per week, each one a 20-minute sleep interruption with no recourse. No major U.S. city has banned car alarms outright, despite their demonstrated uselessness. New York City's noise code limits car alarm duration to 3 minutes, but enforcement requires someone to identify the specific vehicle, file a complaint, and wait for an officer to respond -- by which time the alarm has typically stopped and restarted. The political barrier is that car alarm manufacturers and automotive insurers have successfully framed alarms as a security feature, even though modern anti-theft technology (immobilizers, GPS tracking, encrypted key fobs) has made audible alarms obsolete as a theft prevention tool. Vehicle manufacturers continue to install them as a default feature, creating an installed base of tens of millions of nuisance devices with no coordinated effort to phase them out.