Ambulances And Cop Cars Are Ready To Rumble

Take a look around next time you're stuck in rush hour traffic. The woman in the car next to you is putting on her eye makeup and breastfeeding. The guy on the other side is drinking a coffee, talking on his cell phone, and shaving. All around you, motorists are multitasking and distracted.

Enter the Rumbler Intersection Clearing System, a safety product designed to grab the attention of drivers numb to the flashing lights and blaring sirens of police cars and ambulances. The system allows emergency vehicles to generate a low-level vibration as they approach, the idea being that drivers will look up from their Croissan'wiches just long enough to see that they're about to get nailed by an ambulance.

"People were cocooning themselves so much inside
their vehicles that in some cases, the siren and lights didn't seem to
be enough," says Tom Morgan of Federal
Signal Corp, the company that makes the Rumbler. "That increases the risk to an officer or to the citizens in an area where an emergency is occurring." Well said, Mr. Morgan.

The technology behind the rumbler is surprisingly simple. The complete system includes an amplifier, a timer, an electronic siren (mechanical sirens won't work), and two sub-woofers. When the siren blares, the system reads the output and duplicates it, but drops it to a frequency that is two octaves lower. These low tones, amplified through the sub-woofers, penetrate and shake solid materials, creating a vibration that demands attention. The coffee can sized speakers can be easily installed in vehicle wheel wells, and controls mount under a car's hood or in the trunk.

The Rumbler was designed for installation in Crown Vics, but is also being used in SUVs, Chargers, and Impalas. Sixty different law enforcement agencies, most of them in densely populated urban areas, are using the Rumbler and loving it. The  Metropolitan Police Department in Washington DC has equipped 80 of its Impalas and Crown Vics with the Rumbler, and says the technology has been so successful that it will eventually be deployed fleet wide.

But not everyone is in the Rumbler business. The Citizens Coalition Against Noise Pollution (they'd prefer you call them Noise Off) says that the Rumbler creates an "ear splitting sound" and points out that the product's own marketing materials warn that "sirens and speakers may cause hearing damage." When urging city councils to block purchase and deployment of the Rumbler, Noise Off explains that exposure to this type of noise on a regular basis can result in hearing loss, sleep deprivation, chronic fatigue, anxiety, hostility, depression and hypertension. Not qualities you look for in emergency service professionals.

Not surprisingly, the company disagrees with Noise Off's assessment. Federal Signal's Morgan says that the Rumbler actually operates at 109 dB, versus 119 dB for a standard siren, and 120 dB for a clap of thunder. "I think some people expect it to be like somebody pulling up to them with a boom box going so loud that they see everything start to vibrate around them," he says. "Although it operates on the same kind of principle at lower frequency, it's more subtle than that."

Public reaction to the Rumbler has been mixed, with some drivers complaining that the sound and vibration is annoying. But isn't being annoying the whole point? An irritating vibration sure beats getting blindsided by a police cruiser.

Photo by Flickr user VeryBadLady