Noise Levels in 21678, MD | Find Quiet Neighborhoods With Our Sound Map
45 dBA
Average noise across 21678
Quiet suburban street at night
96
Residents above the EPA 55 dBA threshold
4% of 21678 residents
77 dBA
Loudest residential point
City bus interior
This map shows modeled outdoor noise across 21678 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.
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 96 21678 residents, or 4.4%, live above that level. By land area, 3.2% of 21678 is above 55 dBA.
96.8% below 55 dBA
3.2% above 55 dBA
See how noise in 21678 compares to similar-sized zip codes.
Noise by Part of 21678
Average noise levels for 21678 residents, grouped by direction from the center of 21678. The highest population-weighted average is in southern 21678; the lowest is in eastern 21678, where just 2% of residents live in blocks above the EPA's 55 dBA threshold, three-quarters of the share in the loudest section.
Southern 21678
47.9 dBA · Mostly quiet
Quiet office
Southwestern 21678
44.4 dBA · Quiet
Quiet suburban street at night
Northern 21678
42.9 dBA · Quiet
Quiet suburban street at night
Northwestern 21678
42.8 dBA · Quiet
Quiet suburban street at night
Eastern 21678
42.6 dBA · Quiet
Quiet suburban street at night
To the human ear, noise in southern 21678 sounds about 44% louder than in eastern 21678, a 5.3 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 77 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
77 dBA
City bus interior
165 ft
62 dBA
Busy restaurant
330 ft
54 dBA
Quiet office to normal conversation
660 ft
45 dBA
Quiet suburban street at night
¼ mile
37 dBA
Soft rainfall
½ mile
35 dBA
Soft rainfall
Calculated from the model's calibrated attenuation formula. About 14% of 21678 sits under tree canopy (lighter than most zip codes) and roughly 3% 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 21678. 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 21678
The bar chart below shows the share of 21678 residents in each noise band. About 98% 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 21678 Compares
21678 sits at the quieter end of the spectrum. Below: how 21678's average outdoor noise and share of residents above the EPA threshold compare with 21623, 21661, 21919, and 21635.
Average noise level (dBA)
21678's 45.1 dBA pop-weighted average is at the quieter end of the spectrum. Maryland as a whole averages 52.3 dBA and the U.S. averages 52.0 dBA. Both are lower than 21678 because most of either area is rural land away from major roads.
Share of residents above 55 dBA
About 4.4% of 21678 residents live in blocks where outdoor levels exceed the EPA's 55 dBA threshold. That's fewer than any of its peer group. Measured by land area instead, 3.2% of 21678'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 21678
- 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 14% of 21678 is under tree cover (lighter than most 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.
