[martin8412]

To argue in court that a vehicle is too loud, they'd need a meter in their cars similar to how they measure speed to be able to argue in court that you were speeding. So in effect, you'd have the exact same thing except it would be mobile.

[johnwalkr]

As the article said, several microphones are required to pinpoint the location of sound. Location and distance are very important to measuring sound.

I forget what city recently tried to enforce vehicle noise, but I recall reading that virtually all tickets were thrown out under argument that the distance, angle of meter, nearby materials weren't perfect enough to measure adequately.

Furthermore as far as I've seen, measurements are with a handheld meter after the vehicle is pulled over, not when the driver is wide-open-throttle and over the speed limit.

It makes much more sense to measure from a fixed location while the vehicle is in motion.

[dealuromanet]

You'd need police officers in police cruisers waiting for the sign of trouble. The officers would communicate with one another when they notice a loud vehicle pass by. Then they can use a noise gun to get a decibel reading. This is an intentional physical bottleneck placed on the surveillance apparatus so that it is limited to only identifying and pursuing those cars that are too loud. You would have the same end result if the fines are hefty enough without needing to build and deploy a surveillance dragnet that you won't be able to escape from once it exists.

A town or city would do better with a few police officers in cruisers keeping an eye on things than with these boxes deployed on every streetlight listening 24/7.