This map shows modeled outdoor noise across 21821 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 43 21821 residents, or 5.3%, live above that level. By land area, 7.3% of 21821 is above 55 dBA.
See how noise in 21821 compares to similar-sized zip codes.
Noise by Part of 21821
Average noise levels for 21821 residents, grouped by direction from the center of 21821. Western 21821 carries the highest population-weighted average; Eastern 21821 carries the lowest. Just 2% of residents in Eastern 21821 live in blocks above the EPA's 55 dBA threshold, a fifth of the share in Western 21821.
Eastern 21821
2% of people above 55 dBA
Northern 21821
6% of people above 55 dBA
Southern 21821
3% of people above 55 dBA
Western 21821
23% of people above 55 dBA
Western 21821 sounds about 66% louder than Eastern 21821 to the human ear, a 7.3 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 62 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.
Calculated from the model's calibrated attenuation formula. About 37% of 21821 sits under tree canopy (heavier than most zip codes) and roughly 4% 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.