It's a situation that everyone has experienced - you're walking down the street, when a vehicle drives by that's so loud, people cover their ears and cast angry glances at the driver. You assume that it's illegal to use a muffler that's so ineffective, or to have a stereo turned up that high, but if it is ... how come so many people seemingly get away with it? Well, part of the reason is manpower. While speeders and red-light-runners can be ticketed in the thousands using automated systems, actual police officers need to go out and manually check cars and motorcycles for noise violations. The designer of Noise Snare, however, claims that his unmanned system can automatically detect and identify overly-audible vehicles.

Noise Snare was invented by Mark Nesdoly, an electrical engineer from Edmonton, Canada. He was inspired to create it after a neighbor's loud motorcycle woke up his young daughter.

The system can be covertly mounted on a vehicle, which is then parked and left unattended at a location that municipalities wish to monitor. Once everything is armed, a microphone proceeds to register noise levels of passing vehicles. When a vehicle that exceeds legal noise levels is detected, a video camera captures footage of it, which is recorded - along with stereo audio - to DVD. Information such as the time, date and location of the infraction are superimposed on the footage, along with the vehicle's sound level in decibels.

As with photo radar, vehicle owners are identified via license plate numbers on the footage. Users can simply view the DVD to find out who's getting a ticket, or the system can notify them as it detects violations, via text messages or email. According to Nesdoly's company, Street Noise Reduction Systems, the system is able to accurately identify which specific vehicle is the guilty party, even in heavy traffic or on multi-lane roads.

The city of Calgary will start testing the Noise Snare within the next couple of months, pending council approval, and may become its first adopter.

Below is some test footage captured by the system, of vehicles that exceeded local allowable noise levels.

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