This map shows modeled outdoor noise across South Dennis 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 1,440 South Dennis residents, or 41.1%, live above that level. By land area, 48.6% of South Dennis is above 55 dBA.
See how noise in South Dennis compares to similar-sized cities.
Noise by Part of South Dennis
Average noise levels for South Dennis residents, grouped by direction from the center of South Dennis. The highest population-weighted average is in central South Dennis; the lowest is in northern South Dennis, where just 19% of residents live in blocks above the EPA's 55 dBA threshold, about half the share in the loudest section.
Central South Dennis
44% of people above 55 dBA
Western South Dennis
39% of people above 55 dBA
Southeastern South Dennis
29% of people above 55 dBA
Northeastern South Dennis
22% of people above 55 dBA
Northern South Dennis
19% of people above 55 dBA
To the human ear, noise in central South Dennis sounds about 82% louder than in northern South Dennis, a 8.6 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 US Hwy 6 do you need to be?
US Hwy 6 produces an estimated 73 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 52% of South Dennis sits under tree canopy (heavier than most cities) and roughly 26% 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.