Noise is the No. 1 reason New Yorkers call 311 — from traffic and construction to late-night music, according to the Department of Environmental Protection.

But a new tool aims to help the city crack down on the constant commotion.

The city’s Department of Environmental Protection has launched NYCNoise, a free app that lets users log sound issues in their neighborhoods.

“Report, especially anonymously — it’d be wonderful. Hopefully it’ll clean the city up and stop noise pollution,” one resident said.

The app measures noise levels in decibels over a five-second recording period but does not capture actual audio.

Users instead select the noise source — such as loud music or traffic — after taking the measurement.

“The big problem here is the cars with the big speakers,” another resident said. “They just park, and you can hear it from four blocks away.”

Some say the tool fills a real need.

“Yes, I think it’s needed. Can I use it for neighbors? Yes, definitely,” a resident said.

Noise remains the most common 311 complaint, according to the DEP.

Each app entry logs the time, date and location, giving the city more precise data than ever before.

Still, not everyone is convinced.

“Most of the time when they do something like this, it’s money poured into something that doesn’t give you the results you want,” one resident said.

As more reports come in, the DEP plans to build a noise map to identify hotspots, allowing inspectors to target problem areas and ultimately reduce noise citywide.