Noise Levels in 21631, MD | Find Quiet Neighborhoods With Our Sound Map
47 dBA
Average noise across 21631
Quiet office
219
Residents above the EPA 55 dBA threshold
8% of 21631 residents
74 dBA
Loudest residential point
City bus interior
This map shows modeled outdoor noise across 21631 at 100-meter resolution, combining road, aviation, and rail sources. Green areas measure below 45 dBA. Orange and red exceed the EPA's 55 dBA outdoor threshold linked to long-term health effects. Use the layer toggles to view each source on its own or all together.
Overall
Road
Rail
Aviation
Click the map to explore
35 dBa55 dBa (EPA limit)90+ dBa
3545557090
Quietest (dBA)Loudest
Colorblind friendlyoff
What the numbers sound like
30 dBAWhisper
40 dBASoft rainfall
45 dBAQuiet suburban street at night
50 dBAQuiet office
55 dBAEPA outdoor threshold: light traffic 100 ft away
60 dBANormal conversation an arm's length away
65 dBABusy restaurant
70 dBAHighway traffic 50 ft away
80 dBACity bus interior
Population Above the EPA Outdoor Threshold
The EPA's 55 dBA outdoor reference level is a common benchmark for residential noise exposure, especially for activity interference, annoyance, and long-term community noise concerns. About 219 21631 residents, or 8.4%, live above that level. By land area, 14.3% of 21631 is above 55 dBA.
Average noise levels for 21631 residents, grouped by direction from the center of 21631. Western 21631 carries the highest population-weighted average; Northern 21631 carries the lowest. Just 3% of residents in Northern 21631 live in blocks above the EPA's 55 dBA threshold, about half the share in Western 21631.
Eastern 21631
45.4 dBA · Mostly quiet
Quiet suburban street at night
12% of people above 55 dBA
QuietLoud
Northern 21631
44.1 dBA · Quiet
Quiet suburban street at night
3% of people above 55 dBA
QuietLoud
Southern 21631
46.8 dBA · Mostly quiet
Quiet office
8% of people above 55 dBA
QuietLoud
Western 21631
48.9 dBA · Mostly quiet
Quiet office
8% of people above 55 dBA
QuietLoud
Western 21631 sounds about 39% louder than Northern 21631 to the human ear, a 4.8 dBA gap. Every 10 dBA roughly doubles perceived loudness. Within any of these directions, two homes a quarter mile apart can still differ by 10 or more dBA depending on how close they sit to a major highway.
How far back from do you need to be?
produces an estimated 74 dBA at its loudest centerline points. Noise drops logarithmically with distance, with the exact rate depending on what's between you and the road. Tree cover, walls, terrain, and pavement type all matter. At roughly a quarter mile back, traffic fades into the noise level of a soft rainfall.
At source
74 dBA
City bus interior
165 ft
61 dBA
Normal conversation an arm’s length away
330 ft
54 dBA
Quiet office to normal conversation
660 ft
46 dBA
Quiet office
¼ mile
39 dBA
Soft rainfall
½ mile
35 dBA
Soft rainfall
Calculated from the model's calibrated attenuation formula. About 30% of 21631 sits under tree canopy (about average for zip codes) and roughly 6% is impervious surface like pavement and rooftops. Both are folded into the per-place decay rate above. Heavier canopy pulls noise down faster with distance; impervious surfaces slow the drop.
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Rail Noise
Active freight rail runs through parts of 21631. For most blocks the rail-only contribution is small. Combined road-plus-rail noise rarely exceeds road noise on its own. The exceptions are the handful of blocks within roughly a quarter mile of the right-of-way during pass-through hours.
Use the Rail toggle on the map above to isolate rail's contribution from road and aviation.
How Noise Is Distributed Across 21631
The bar chart below shows the share of 21631 residents in each noise band. About 93% of residents live below the EPA's 55 dBA threshold, and roughly 0% live in blocks above 60 dBA. Long-term exposure in that range is linked to elevated stress hormones and cardiovascular risk.
How 21631 Compares
21631 sits at the louder end of the spectrum. Below: how 21631's average outdoor noise and share of residents above the EPA threshold compare with 21673, 21837, 21663, and 21625.
Average noise level (dBA)
21631's 46.6 dBA pop-weighted average is at the louder end of the spectrum. Maryland as a whole averages 52.3 dBA and the U.S. averages 52.0 dBA. Both are lower than 21631 because most of either area is rural land away from major roads.
Share of residents above 55 dBA
About 8.4% of 21631 residents live in blocks where outdoor levels exceed the EPA's 55 dBA threshold. That's in the middle of its peer group. Measured by land area instead, 14.3% of 21631's footprint sits above 55 dBA, against a Maryland average of 32.9% and a national average of 28.1%.
What This Means if You're Moving to 21631
Distance from highways matters more than the neighborhood name. Two homes in the same zip code can differ by 20 dBA if one sits 100 meters from and the other 500 meters away. The model captures this at 100-meter resolution, so noise exposure changes block by block.
Tree canopy can help reduce modeled noise exposure. Roughly 30% of 21631 is under tree cover (about average for zip codes), and the dominant land cover is cultivated cropland. Both are measured from federal USDA Forest Service and USGS satellite imagery at 30-meter resolution. Streets with 60% or higher canopy show 3 to 5 dBA lower noise than comparable streets with bare ground or pavement, which is why the per-place decay rate above already accounts for it.
Sources & Methodology
The BestNeighborhood noise model is calibrated against nearly one million federal ground-truth measurements across four states. Road noise is computed from segment-level federal traffic data and propagated outward using physics-based acoustic decay, with attenuation rates that depend on the surrounding land cover.
All inputs are published federal datasets. Block-level noise is computed by combining road, rail, and aviation sound sources in the energy domain, the same physics used in professional environmental noise assessments. Read the full methodology.
