Noise Levels in Sulphur, SD | Find Quiet Neighborhoods With Our Sound Map
53 dBA
Average noise across Sulphur
Quiet office to normal conversation
216
Residents above the EPA 55 dBA threshold
23% of Sulphur residents
80 dBA
Loudest residential point
City bus interior
This map shows modeled outdoor noise across Sulphur 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 216 Sulphur residents, or 22.9%, live above that level. By land area, 32.2% of Sulphur is above 55 dBA.
67.8% below 55 dBA
32.2% above 55 dBA
See how noise in Sulphur compares to similar-sized cities.
Noise by Part of Sulphur
Average noise levels for Sulphur residents, grouped by direction from the center of Sulphur. Southern Sulphur carries the highest population-weighted average; Western Sulphur carries the lowest. Just 4% of residents in Western Sulphur live in blocks above the EPA's 55 dBA threshold, a fifth of the share in Southern Sulphur.
Central Sulphur
52.1 dBA · Moderate
Quiet office to normal conversation
Northern Sulphur
52.1 dBA · Moderate
Quiet office to normal conversation
Southern Sulphur
56.9 dBA · Moderate-loud
Normal conversation an arm’s length away
Western Sulphur
48.8 dBA · Mostly quiet
Quiet office
Southern Sulphur sounds about 75% louder than Western Sulphur to the human ear, a 8.1 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 80 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 quiet suburban street at night.
At source
80 dBA
City bus interior
165 ft
67 dBA
Highway traffic 50 ft away
330 ft
60 dBA
Normal conversation an arm’s length away
660 ft
52 dBA
Quiet office to normal conversation
¼ mile
45 dBA
Quiet suburban street at night
½ mile
38 dBA
Soft rainfall
Calculated from the model's calibrated attenuation formula. About 0% of Sulphur sits under tree canopy (much lighter than most cities) and roughly 10% 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.
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How Noise Is Distributed Across Sulphur
The bar chart below shows the share of Sulphur residents in each noise band. About 74% of residents live below the EPA's 55 dBA threshold, and roughly 0% live in blocks above 60 dBA. Long-term exposure in that range is linked to elevated stress hormones and cardiovascular risk.
How Sulphur Compares
Sulphur sits at the louder end of the spectrum. Below: how Sulphur's average outdoor noise and share of residents above the EPA threshold compare with Johnson Siding, Keystone, Ashland Heights, and New Underwood.
Average noise level (dBA)
Sulphur's 53.2 dBA pop-weighted average is at the louder end of the spectrum. South Dakota as a whole averages 52.6 dBA and the U.S. averages 52.0 dBA. Both are lower than Sulphur because most of either area is rural land away from major roads.
Share of residents above 55 dBA
About 22.9% of Sulphur residents live in blocks where outdoor levels exceed the EPA's 55 dBA threshold. That's in the middle of its peer group. Measured by land area instead, 32.2% of Sulphur's footprint sits above 55 dBA, against a South Dakota average of 20.8% and a national average of 28.1%.
What This Means if You're Moving to Sulphur
- Distance from highways matters more than the neighborhood name. Two homes in the same zip code can differ by 20 dBA if one sits 100 meters from and the other 500 meters away. The model captures this at 100-meter resolution, so noise exposure changes block by block.
- Tree canopy can help reduce modeled noise exposure. Roughly 0% of Sulphur is under tree cover (much lighter than most cities), and the dominant land cover is grassland. Both are measured from federal USDA Forest Service and USGS satellite imagery at 30-meter resolution. Streets with 60% or higher canopy show 3 to 5 dBA lower noise than comparable streets with bare ground or pavement, which is why the per-place decay rate above already accounts for it.
