This map shows modeled outdoor noise across Grand Isle 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 16 Grand Isle residents, or 0.8%, live above that level. By land area, 0.6% of Grand Isle is above 55 dBA.
See how noise in Grand Isle compares to similar-sized cities.
Noise by Part of Grand Isle
Average noise levels for Grand Isle residents, grouped by direction from the center of Grand Isle. Eastern Grand Isle carries the highest population-weighted average; Central Grand Isle carries the lowest. Just 0% of residents in Central Grand Isle live in blocks above the EPA's 55 dBA threshold, a fifth of the share in Eastern Grand Isle.
Central Grand Isle
0% of people above 55 dBA
Eastern Grand Isle
0% of people above 55 dBA
Northern Grand Isle
1% of people above 55 dBA
Southern Grand Isle
2% of people above 55 dBA
Western Grand Isle
0% of people above 55 dBA
Eastern Grand Isle sounds about 22% louder than Central Grand Isle to the human ear, a 2.9 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 Th-1 do you need to be?
Th-1 produces an estimated 49 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 46% of Grand Isle sits under tree canopy (heavier than most cities) and roughly 1% 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.