This map shows modeled outdoor noise across Great Brook Valley 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 1,073 Great Brook Valley residents, or 35.7%, live above that level. By land area, 39.4% of Great Brook Valley is above 55 dBA.
See how noise in Great Brook Valley compares to similar-sized neighborhoods.
Noise by Part of Great Brook Valley
Average noise levels for Great Brook Valley residents, grouped by direction from the center of Great Brook Valley. Southern Great Brook Valley carries the highest population-weighted average; Western Great Brook Valley carries the lowest. Just 0% of residents in Western Great Brook Valley live in blocks above the EPA's 55 dBA threshold, a fifth of the share in Southern Great Brook Valley.
Central Great Brook Valley
31% of people above 55 dBA
Northern Great Brook Valley
14% of people above 55 dBA
Southern Great Brook Valley
80% of people above 55 dBA
Western Great Brook Valley
0% of people above 55 dBA
Southern Great Brook Valley sounds about 89% louder than Western Great Brook Valley to the human ear, a 9.2 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 65 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 18% of Great Brook Valley sits under tree canopy (about average for neighborhoods) and roughly 57% 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.