Calgary police Howler car: How it works

You're listening to your favourite song on the radio and cruising down the highway when suddenly, your steeringwheel feels shaky and your whole body starts tovibrate.

No, it's not an earthquake,it's probablya police car trying to get your attention with their new Howlersystem, a low frequency amplifier.

"You kind of feel it in your bones, you kind of feel it in your body as it emits that low vibration," saysInsp. Ken Thrower, commanderof the Calgary policetraffic section.

Two years ago, Calgary Police Service started to change over their fleetwith brand new blackandwhite vehicles. All marked and unmarked vehiclescomeequipped with the device.

So far, 180 Howlercars are on the road. That number will reach 375 in the next two years.

"It's really an assist to the siren when the police car is in an emergency situation," says Thrower.

"Officers tell me they believe that people are more aware now when they come up to an intersection, for example."

No broken windows

According toThrower, some people expressed concernson social media that the device would damage property.

So the CBC went out withCalgary mother Marie-Pier Reid and her babyto testthe device.

The police followed and "howled"at Reid's SUV from about fivemetres without disturbing her three-month-old baby.

"I hear a kind of loud and deep noise," she said during the experiment.

"It feels like they are super close, though, it feels like they are in the car with us. It's buzzing."

Not everyone can feel the device and location has a lot to do with the feeling, says Thrower.

"It depends on the environment, the conditions, the buildings around.... Maybe onDeerfootit won't be asnoticeable, I would say that downtown, it would be morenoticeableto people walking by, and it's a high pedestrian area."

The frequencies have a total range of 60 metres.