Brockton, MA Noise from Specific Sources: Car Alarm Limits (2026)

Chapter 14, Sec. 14-50 is Brockton's citywide noise-control ordinance, and it lists specific noise sources exempt from its general restrictions. Under subsection (g)(1)f, "noise created by warning devices not operated continuously for more than thirty minutes per incident" is exempt from the noise code at all times, which covers a car alarm that sounds briefly. Once an alarm runs past 30 continuous minutes, that exemption no longer applies and the sound falls back under the general noise restrictions in subsection (d): it is unlawful to "make, generate or be the cause of" any noise that "annoys, disturbs, injures, and/or endangers the comfort, repose, health, peace, and/or safety" of other residents.

m. m. Friday and Saturday), the ordinance caps noise at 50 decibels measured from 50 feet away or the nearest lot line. Enforcement runs through the Brockton Police Department: officers use standard electronic sound meters to confirm a violation, and a first substantiated complaint results in a written warning logged in the department's computer system, with a copy mailed to the property's owner of record within seven days.