Immobilizers, not loud noise, effective in stopping automobile theft

Car alarms would appear to be the perfect modern-day example of the classic fable, "The Boy Who Cried Wolf." The kid reported so many false alarms that his weary neighbors paid no mind when a hungry wolf actually showed up looking for lunch meat.

The New York Police Department published a pamphlet a few years back, "Police Strategy No. 5," that called car theft deterrents that emit an audible alarm an "annoying and sometimes unbearable disturbance for residents in their homes;" they "frequently go off for no apparent reason;" and, as one of the "signs that no one cares," they "invite both further disorder and serious crime."

The auto insurance industry, which has a financial interest in the best possible theft prevention, conducted a study that shows "car alarms do nothing to stop car theft." The car alarm industry, of course, would beg to differ. Industry spokesmen point to statistics that show a drop in car thefts in general in recent years as "proof" their products work. Actually, the drop in thefts would seem to correspond to the increasing popularity of silent alternatives.

The NYPD says it has no evidence that audible alarms work; it has no statistical proof on the arrests (if any) that vehicle alarms have led to. In fact, a department spokesman admitted officers usually ignore the alarms.

New York City has sought to ban sale, installation, and use of audible car alarms as a public nuisance. A group called "The Silent Majority" calls audible alarms, which can exceed 125 decibels, a health hazard. The World Health Organization warns that even for those who think they can "tune out" or ignore such noise, physical tests show "increased levels of stress hormone and elevation of resting blood pressure."

Silent alternatives seem to be winning the battle for acceptance in the marketplace. Another insurance industry study has found immobilizers, which disable a vehicle's electrical system if tampered with, cut theft rates "in half"; the same study found cars with audible alarms "show no overall reduction in theft losses."

Opponents of audible car alarms say "a vast majority" of alarm activations are "false alarms." Such alarms can be triggered by vibration, touching, electrical malfunctions, and even weather . People within earshot of such alarms have in many cases been found to be "conditioned" not to pay any attention to them. Many car owners report they don't even respond to their own car's alarm going off.

Automobile manufacturers such as General Motors and Ford report only a fraction of their customers even ask for audible alarms anymore. Most vehicles nowadays come with "security systems," which include technology like immobilizers. All Harley-Davidson motorcycles for 2006 have immobilizers that deactivate the bike's electronics when someone tries to start the vehicle, unless the correct key is in the ignition.

Most audible alarms are very easy to disable; since they need an electrical source to provide power to the alarm, cutting a wire is usually all it takes to defeat them.

Statistics show about 80 percent of stolen cars are taken by professional thieves, who know how to deactivate an alarm in just a few seconds.

Anti theft devices such as vehicle immobilizers, tracking systems, and silent pagers have proven to be much more problematic for thieves to defeat, and in many cases they cost no more than would an elaborate audible alarm.

The NYPD recommends that owners of vehicles with audible alarms have them removed and replaced with one of these more effective silent alternatives.