The term “noise pollution” first appeared in a 1966 New England Journal of Medicine article about the negative health effects of unwanted sound. Six years later the federal Noise Control Act was adopted, making it “…the policy of the United States to promote an environment for all Americans free from noise that jeopardizes their health or welfare.”
In the five decades since, however, sound seems to have grown in volume. According to the World Health Organization, noise is the second largest environmental cause of health problems, after air pollution.
Controlling excessive sound has largely been a local responsibility, with many cities, including San Francisco, relying on the 311 system to take noise complaints from citizens and allow them to track the response, something that’s more easily accomplished when the racket is coming from a fixed position, such as a party in a park or the neighbor’s house.
According to the 311 data, there were 67 noise complaints registered in Potrero Hill and Dogpatch in the six months between April and September 2023, on average one every three days. By way of comparison, there were 1,285 complaints about graffiti in the same neighborhoods during the same period.
One of the most difficult sources to control is the loud car.
Most gasoline-powered vehicles have a noise level of less than 75 decibels (dBs) thanks to the muffler in their exhaust system. Electric vehicles, on the other hand, are so quiet at slow speeds that the National Highway Traffic Safety Administration requires that they produce sound ranging from 43 to 64 dBs to ensure pedestrians can hear them approaching.
Some drivers want their gas-powered cars to be louder, an outcome that can be achieved through a combination of after-market parts or “muffler deletes,” a euphemism for removing the device from the automobile. California vehicle code allows these modifications so long as the vehicle weighs less than 6,000 pounds and the sound level doesn’t exceed 95 decibels, about equal to the average gas-powered lawnmower.
In the past, police issued “fix-it” tickets which allowed violators 30 days to make the necessary repairs. Assembly Bill 1824, passed in 2019, eliminated the grace period and made citations mandatory. Fines for first-time offenders are now around $200, with repeat offenders subject to up to $1,000 in penalties.
But while a radar gun can catch a speeding driver, how can law enforcement detect and identify moving vehicles with engines exceeding the 95 dB limit allowed by the code? Enter the noise camera, a device which combines audio monitoring with picture-taking technology similar to what’s used in red light violation devices and toll gathering systems at Bay Area bridges.
Noise cameras – which are distinct from ShotSpotter, a non-camera system that deploys up to 25 microphones per square mile to allow human operators to listen for gunfire – are being produced by two companies: SoundVue by United Kingdom-based Intelligent Instruments and Not-A-Loud in New Mexico. Not-A-Loud is the brainchild of Nick Ferenchak, a civil engineering professor at the University of New Mexico who specializes in traffic safety issues. He started the company shortly after he moved to Albuquerque in 2018.
“I was hiking about 20 miles east of downtown in the Sandia Mountains,” he said. “And I could still hear the traffic. I just remember thinking, ‘This is not okay.’”
In addition to the health problems that may be exacerbated by road noise, Ferenchak has identified a link between louder cars and more dangerous driving behaviors, such as speeding. He hopes the technology will reduce noise pollution and curtail other more deadly outcomes.
According to a 2023 survey reported by SkyNews, 58 percent of drivers in the United Kingdom favored using the technology to catch loud vehicles, while 44 percent were opposed or unsure. The SoundVue system has been tested in New York City and Knoxville, Tennessee, where 1,300 cars triggered the camera in the first six months of operation. Ferenchak’s device, which secured a patent earlier this year, has been tried in Santa Fe and Albuquerque.
Noise cameras, as well as less sophisticated devices, could be used to monitor static sources, such as intermittent late-night partying at Esprit, Jackson, Dolores, or other parks, creating an ability to dispatch Recreation and Park Department rangers without having to rely on angry citizen complaints.
Thomas Hunter II 
Jessica Zimmer