Area Noise Monitoring: Workplace vs Property-Line Surveys
When a California facility calls and says “we need a noise survey,” the first job is figuring out which kind.
When a California facility calls and says “we need a noise survey,” the first job is figuring out which kind. The phrase covers two completely different services that share a name, a unit of measurement (dBA), and almost nothing else.
A workplace noise survey measures employee exposure inside the facility against Cal/OSHA limits. A property-line or community noise survey measures sound at the facility boundary against a city or county ordinance. Different regulators, different methods, different equipment settings, different reports. Picking the wrong one wastes money and doesn’t answer the question that triggered the call.
This piece walks through the differences so you can route your situation correctly. For the full overview of how noise fits into the rest of your facility’s exposure assessments, see our industrial hygiene services in California pillar.
Two Surveys, Two Different Questions
A workplace noise survey answers: are my employees overexposed to noise on the job? The benchmark is Cal/OSHA’s 85 dBA action level and 90 dBA permissible exposure limit, calculated as an 8-hour time-weighted average (TWA). The driver is usually a Cal/OSHA inspection, an employee complaint, an insurance request, or a hearing conservation program review. The detail on the regulation itself sits in our OSHA noise monitoring requirements guide.
A property-line or community noise survey answers: is the noise leaving my facility within the limits set by the city or county? The benchmark is a local noise ordinance, often expressed as dBA limits by zoning category (commercial, light industrial, residential) and time of day. The driver is almost always a neighbor complaint, a planning department request, a conditional use permit, or a CEQA-related noise study.
The most common source of confusion: someone calls because a neighbor complained, and they assume Cal/OSHA noise rules apply. They don’t. We had an inbound this spring where the request had to be reframed on the first call: “this is more of a community noise survey rather than an OSHA thing.” Residential inquiries (homeowners worried about a 24/7 neighbor noise problem) also land in the same bucket and need the same redirect.
Side-by-Side Comparison
| Dimension | Workplace Noise Survey | Property-Line / Community Noise Survey |
|---|---|---|
| Question it answers | Is employee exposure over the action or permissible limit? | Is sound at the facility boundary within local ordinance limits? |
| Regulator | Cal/OSHA (8 CCR §5095–5097) and federal OSHA (29 CFR 1910.95) | City or county planning or code enforcement; sometimes CEQA review |
| Benchmark | 85 dBA TWA (action level) / 90 dBA TWA (PEL) | Local ordinance, often a zoning-based dBA limit (e.g., 70 dBA at a commercial or industrial line, lower at a residential line, with night-time reductions) |
| Where you measure | Inside the facility, breathing zone of the employee or at workstation | Outside, at the property boundary nearest the receiver |
| Equipment | Personal audio dosimeter and/or area sound level meter | Integrating sound level meter, often with octave-band capability; sometimes long-term unattended logging |
| Settings | Threshold 80 dB, criterion 90 dB, 5 dB doubling, A-weighting, slow response | Per local ordinance; often includes tonal and impulsive component adjustments |
| Duration | 6 to 8 hour shift, representative of normal operations | Varies by ordinance: short sample, full daytime period, or 24-hour log |
| Deliverable | TWA comparison to action and permissible levels; hearing conservation recommendation | Boundary measurements compared to ordinance limits; mitigation recommendations |
| Triggers the next step | Hearing conservation program if TWA reaches 85 dBA | Source-control or barrier recommendations; possible permit condition response |
Workplace Noise Surveys: How They Work
A workplace noise survey is the industrial hygiene measurement that determines who, if anyone, must be enrolled in a hearing conservation program under Cal/OSHA Title 8, §5097. We deploy calibrated dosimeters worn by representative employees through their normal shift, with the regulation’s required settings (80 dB threshold, 90 dB criterion, 5 dB doubling rate, A-weighting, slow response). The report tabulates each employee’s 8-hour TWA against the 85 and 90 dBA thresholds and tells you whether a hearing conservation program is required.
When we walk a facility for a workplace survey, the first thing we look at is whether the work is consistent throughout the shift or has peak periods. A six-hour TWA can miss a one-hour peak that drives the day. The second thing we confirm is whether employees rotate tasks. Rotating roles change the sampling strategy. For deeper detail on how workplace surveys are run and what the report contains, see our noise monitoring services page.
Property-Line and Community Noise Surveys: How They Work
A property-line noise survey is a different animal. The receiver is not an employee inside the building, it is a neighbor across the fence. The benchmark is not Cal/OSHA, it is whatever the local jurisdiction’s noise ordinance says. Cities and counties in California write their own ordinances, so the limits, time-of-day adjustments, and measurement protocols vary. Most ordinances set different dBA limits for daytime and night-time and reduce the allowed level at residential boundaries.
Property-line work also looks at tonal and impulsive components. A steady fan hum at 65 dBA can be code-compliant on a raw dBA reading but still violate an ordinance because the tone is recognizable and penalized. Boundary measurements typically involve longer measurement durations, statistical metrics that separate the source from background, and a written comparison against the specific ordinance section that applies.
If your facility is going through a conditional use permit, a CEQA noise study, or a code enforcement complaint, this is the service you need. A workplace noise survey will not produce the data the planning department or code enforcement officer is asking for.
How to Tell Which One You Need
Use this short decision check:
- Who is asking? Employee, safety manager, insurance carrier, or Cal/OSHA inspector → workplace survey. Neighbor, planning department, code enforcement, or your land-use attorney → property-line survey.
- Where is the concern? Inside the facility, at a workstation, around loud equipment → workplace. Outside the building, at the fence, in a nearby home → property-line.
- What rule is being cited? Cal/OSHA, OSHA, 85 dBA, hearing conservation → workplace. City or county noise ordinance, zoning, “after 10 p.m.” → property-line.
- What is the deliverable used for? Defending against a Cal/OSHA citation or kicking off a hearing conservation program → workplace. Responding to a complaint, satisfying a permit condition, or supporting a CEQA filing → property-line.
If you genuinely have both problems (loud operations inside and noise leaving the building), they are two separate engagements with two separate reports. The dosimeter data and the boundary data are not interchangeable.
What Happens After Each Survey
The follow-on path is different too. A workplace survey that comes back at or above 85 dBA triggers a hearing conservation program: audiometric testing, hearing protection, training, and annual review. Our next-steps guide for a survey that exceeded 85 dBA walks through what that program looks like. A property-line survey that exceeds an ordinance limit triggers mitigation: source enclosures, barriers, schedule changes, or equipment replacement, depending on what is feasible. Confusing the two means recommending the wrong fix.
Started with a phone-app reading? See what separates app data from a defensible survey →
Trusted throughout California
BSY started working with CDMS last year after our in-house EHS person departed the company. CDMS reviewed our existing operational permits as well as any additional Federal, State and Local regulations that could apply and helped us to create a comprehensive compliance calendar to track regulatory deadlines and submittal due dates. The CDMS team does an excellent job of tracking everything and can be relied upon to complete the forms accurately and assist with submittals, allowing me to focus on our business.
Speak with a CDMS EHS expert
Tell us about your facility and your deadline. You’ll get a clear read on what applies and a scoped plan to handle it.