On the worst nights, when the thudding bass from a nearby nightclub rattled his windows and drowned out the sound on his TV, the noise in John Heaney’s home in Providence felt more like an intruder than a nuisance.

“It’s a true violation because you can’t stop it,” he said. “It’s like someone has a key to your house, and they can come in whenever they want.”

Driven to activism, Mr. Heaney, a retired software engineer, joined a small group of residents in the Rhode Island capital who have lobbied city officials in recent years to crack down on excessive noise. Their campaign, known as the Providence Noise Project, has won vocal support from Mayor Brett Smiley, a Democrat who took office last year. But it has also raised complicated questions about noise, including what to do when not everyone agrees it’s a problem, and how to fairly enforce limits.

Across the city of 190,000 — which is split by Interstate 95, a major source of noise — there is little consensus on the issue. In each of its compact neighborhoods, sirens wail, motorbikes buzz like angry insects, ice cream trucks shriek singsong melodies, and car stereos scatter staccato beats. Some people wince at the cacophony; others barely notice.

Similarly, while some see a clear path, driven by data, to change the behaviors that lead to noise complaints, others are wary, anticipating prejudice and racial profiling.