New York City is known for its noise. A cacophony of sounds bombards residents every time they step outside — screeching subway cars, jackhammers drilling away, late-night revelers leaving bars and clubs.

Still, more than 50,000 noise complaints are filed every year by New Yorkers who have become fed up with the commotion, according to a spokesman for the city’s Department of Environmental Protection.

The noise generated by vehicles, including cars with modified mufflers, loud motorcycles and drivers who honk excessively, accounts for only a small fraction of those complaints, the spokesman said, but it’s the target of a new tool intended to turn down the city’s volume: noise cameras.

The cameras are activated when they record a sound louder than 85 decibels, which is about as loud as a lawn mower. And they are increasingly being used by the Department of Environmental Protection to ticket drivers, according to Rohit T. Aggarwala, the department’s commissioner.