Mayor James J. Fiorentini and Police Chief Alan DeNaro have launched Operation Quiet to keep Haverhill peaceful during the July Fourth holiday and beyond. “Every year at this time, my office is besieged with complaints from residents about noise throughout the city,” Fiorentini said in a written statement. “Our residents deserve peace and quiet.” Two police officers have been assigned to an unmarked car and will be patrolling neighborhoods, ticketing people who are making excessive noise, playing loud music, or shooting off fireworks, which are illegal in Massachusetts. The officers, who will be carrying noise meters, will issue tickets and fine violators. City code prohibits excessive noise as measured on the A-weighted decibel system. Excessive noise is defined as noise from music devices, car and motorcycle exhaust systems, and other sources in excess of 50 dBA, which is equivalent to the noise generated by a refrigerator, between the hours of 11 p.m. and 7 a.m. Fines also will be assessed for noise in excess of 70 dBA, equivalent to the sound of a garbage disposal, at all other hours. To report a problem, call the Police Department at 978-373-1212.