11 county-level rules, plus city-specific rules for 1 city in Los Angeles County, California.
Verified from official government sources
HVAC systems and mechanical equipment in unincorporated LA County must comply with Chapter 12.08 exterior noise standards. Residential HVAC units cannot exceed 50 dBA daytime or 45 dBA nighttime at the neighboring property line.
Bars and entertainment venues in unincorporated LA County must comply with Chapter 12.08 exterior noise standards. Commercial zone limits are 60 dBA daytime and 55 dBA nighttime. Conditional use permits often impose stricter noise conditions.
Car alarms in unincorporated LA County are regulated under Chapter 12.08 and California Vehicle Code §22651.5. Alarms sounding for extended periods may result in vehicle towing. Owners are responsible for ensuring alarms do not create a nuisance.
Generators and power equipment in unincorporated LA County must comply with Chapter 12.08 exterior noise standards. Portable generators commonly exceed residential noise limits and should use sound enclosures. Emergency generators have limited exemptions.
FAA federal preemption blocks LA County from regulating helicopter altitude or routes. Title 12.08.330 still bars willful operation creating disturbing ground noise. LASD Air Support, news, traffic, and hospital helipads dominate countywide rotorcraft activity.
LA County Code §12.08.440 caps powered construction equipment at 75 dBA measured at 50 feet from the source in unincorporated areas. Work allowed Mon-Sat 7am-8pm; banned on Sundays and holidays. LASD and DPW handle citations.
LA County Code §12.08.500 limits motor-vehicle noise to 75 dBA at 50 feet on local streets. California Vehicle Code §27007 bans amplified sound systems audible 50 feet from a truck. Early-morning grocery and trash deliveries draw most complaints.
Federal law preempts LA County from designating helicopter flight paths. The LA Helicopter Noise Coalition, FAA, and operators publish voluntary routes over freeway corridors and avoid residential overflight where practical. LASD Air Support and tour operators participate but compliance is non-binding.
Hospital helipads in LA County need a building permit under California Building Code §1503.3 plus LACOFD Title 32 fire approval. Medevac flights enjoy emergency exemptions from §12.08.330 noise rules, but routine training flights must minimize residential disturbance.
LA County does not regulate aircraft engine run-ups; airport operators do. LAX (Los Angeles World Airports) caps run-ups at designated bays with hush-house enclosures. Bob Hope (Burbank) restricts maintenance run-ups overnight. Long Beach Airport's Noise Ordinance is the strictest in California.
LA County Code Title 12.08 measures low-frequency bass from sound systems on the C-weighted scale, capping levels at 60 dB(C) inside neighboring residences in unincorporated areas. LASD investigates throbbing-bass complaints from clubs, parties, and modified vehicles.
1 cities in Los Angeles County have their own noise from specific sources rules. Each link goes to that city's dedicated page with code citations.
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