This map shows modeled outdoor noise across Marietta Historic District 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 1,025 Marietta Historic District residents, or 30.3%, live above that level. By land area, 36.3% of Marietta Historic District is above 55 dBA.
See how noise in Marietta Historic District compares to similar-sized neighborhoods.
Noise by Part of Marietta Historic District
Average noise levels for Marietta Historic District residents, grouped by direction from the center of Marietta Historic District. Southern Marietta Historic District carries the highest population-weighted average; Eastern Marietta Historic District carries the lowest. Just 12% of residents in Eastern Marietta Historic District live in blocks above the EPA's 55 dBA threshold, a third of the share in Southern Marietta Historic District.
Central Marietta Historic District
43% of people above 55 dBA
Eastern Marietta Historic District
12% of people above 55 dBA
Northern Marietta Historic District
11% of people above 55 dBA
Southern Marietta Historic District
42% of people above 55 dBA
Western Marietta Historic District
40% of people above 55 dBA
Southern Marietta Historic District sounds about 44% louder than Eastern Marietta Historic District to the human ear, 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 Front St do you need to be?
Front St produces an estimated 57 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 25% of Marietta Historic District sits under tree canopy (heavier than most neighborhoods) and roughly 41% 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.