This map shows modeled outdoor noise across Hemphill 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 125 Hemphill residents, or 5.2%, live above that level. By land area, 8.7% of Hemphill is above 55 dBA.
See how noise in Hemphill compares to similar-sized cities.
Noise by Part of Hemphill
Average noise levels for Hemphill residents, grouped by direction from the center of Hemphill. The highest population-weighted average is in northwestern Hemphill; the lowest is in southern Hemphill, where just 0% of residents live in blocks above the EPA's 55 dBA threshold, a third of the share in the loudest section.
Northwestern Hemphill
1% of people above 55 dBA
Northeastern Hemphill
1% of people above 55 dBA
Southeastern Hemphill
0% of people above 55 dBA
Southern Hemphill
0% of people above 55 dBA
To the human ear, noise in northwestern Hemphill sounds about 21% louder than in southern Hemphill, a 2.8 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 60 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 60% of Hemphill sits under tree canopy (heavier than most cities) and roughly 6% 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.