This map shows modeled outdoor noise across Northern Arizona University 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 3,227 Northern Arizona University residents, or 33.3%, live above that level. By land area, 50.3% of Northern Arizona University is above 55 dBA.
See how noise in Northern Arizona University compares to similar-sized neighborhoods.
Noise by Part of Northern Arizona University
Average noise levels for Northern Arizona University residents, grouped by direction from the center of Northern Arizona University. Southern Northern Arizona University carries the highest population-weighted average; Eastern Northern Arizona University carries the lowest. Just 3% of residents in Eastern Northern Arizona University live in blocks above the EPA's 55 dBA threshold, a fifth of the share in Southern Northern Arizona University.
Central Northern Arizona University
24% of people above 55 dBA
Eastern Northern Arizona University
3% of people above 55 dBA
Northern Northern Arizona University
54% of people above 55 dBA
Southern Northern Arizona University
57% of people above 55 dBA
Southern Northern Arizona University sounds about 168% louder than Eastern Northern Arizona University to the human ear, a 14.2 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 ~~i~040~~~~~~~~~~~~~~~~~~~~~~~~~ do you need to be?
~~i~040~~~~~~~~~~~~~~~~~~~~~~~~~ produces an estimated 76 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 10% of Northern Arizona University sits under tree canopy (lighter than most neighborhoods) and roughly 56% 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.