This map shows modeled outdoor noise across Middlesex County 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 576 Middlesex County residents, or 5.6%, live above that level. By land area, 8.8% of Middlesex County is above 55 dBA.
See how noise in Middlesex County compares to similar-sized counties.
Noise by Part of Middlesex County
Average noise levels for Middlesex County residents, grouped by direction from the center of Middlesex County. Western Middlesex County carries the highest population-weighted average; Northern Middlesex County carries the lowest. Just 2% of residents in Northern Middlesex County live in blocks above the EPA's 55 dBA threshold, about half the share in Western Middlesex County.
Eastern Middlesex County
6% of people above 55 dBA
Northern Middlesex County
2% of people above 55 dBA
Southern Middlesex County
4% of people above 55 dBA
Western Middlesex County
6% of people above 55 dBA
Western Middlesex County sounds about 24% louder than Northern Middlesex County to the human ear, a 3.1 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 67 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 48% of Middlesex County sits under tree canopy (much heavier than most counties) 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.