How the NoiseAbove Score works
The score rates how much aircraft noise reaches the ground at a location, from 1 (minimal) to 10 (extreme). It is built from a year of recorded flight tracks, not from airport forecasts, and it covers every kind of aircraft that broadcasts its position: airliners, business jets, small planes, helicopters, crop dusters and some military aircraft.
The score
Each 1.5 km grid cell gets two sub-scores, and the score is the higher of the two:
- Average level: the day-night average sound level (DNL) from aircraft alone, with night noise (10 pm–7 am) weighted +10 dB as the FAA does.
- How often: loud overflights per day (aircraft louder than 60 dBA outdoors), counting each night overflight three times because it can disturb sleep.
| Score | Label | Average level (DNL) | Loud overflights per day |
|---|---|---|---|
| 1 | Minimal | under 35 dB | under 0.5 |
| 2–3 | Minor | 35–45 dB | 0.5–5 |
| 4–5 | Moderate | 45–55 dB | 5–20 |
| 6–7 | Major | 55–61 dB | 20–75 |
| 8–9 | Severe | 61–70 dB | 75–300 |
| 10 | Extreme | 70 dB and up | 300 and up |
For reference, the FAA treats 65 dB DNL as significant for residential use, and a quiet rural area without aircraft is typically 35–45 dB from all sources.
Confidence
Flight positions come from a volunteer network of ground receivers. Near the ground, coverage has gaps, especially in mountains and remote areas. Each location gets a confidence rating from how much low flying the network tracked within about 7 km over the year. One sighting is one aircraft seen below about 2,000 ft above ground in one 1.5 km cell within 10 minutes, so a single low pass usually adds several sightings.
- High: about 8 or more low-flight sightings a day (3,000 a year). Receivers clearly see low aircraft here.
- Medium: about 1 to 8 a day (300 to 3,000 a year).
- Low: fewer than about 1 a day. Either almost nothing flies low here, or receivers can't see it. Low helicopters, crop dusters and military flights may be missed, so a low score here is less certain.
For example, towns with an airport and good receiver coverage see tens of thousands of sightings a year. Yuma, Arizona, which has scheduled airline and military flights, shows fewer than 100, so its quiet reading is rated Low.
Towns within 25 km of a military or joint-use airfield are also flagged: many military jets fly without broadcasting their position.
How it's calculated
- Flight tracks. Every 3rd day for a year, every aircraft position (every 10 seconds) below 20,000 ft over the 50 states, from the adsb.lol public archive.
- Aircraft identity. Each aircraft's transponder code is matched to the FAA aircraft registry for make, model, engine type and weight class. Aircraft not in the registry (military, foreign, anonymous) are classed by their speed.
- Loudness. Each aircraft family gets an estimated maximum sound level 1,000 ft below it, for climbing and for level or descending flight (our own estimates, rounded, typically within 3–5 dB).
- Sound at the ground. Tracks are interpolated to 2-second steps. Sound fades with distance, air absorption and extra ground loss for aircraft low on the horizon (SAE AIR 1751). Height above ground uses terrain elevation.
- Totals. Sound energy is summed per cell to give DNL. Each pass louder than 60 or 70 dBA at a cell is counted once.
Known limits
- Estimates from a model, not microphone measurements. Expect a few dB of error, more for unusual aircraft.
- Many military aircraft don't broadcast their position, so military noise is undercounted. Military training routes and operating areas are shown on the map for that reason.
- Altitudes are uncorrected pressure altitudes, and the grid is 1.5 km, so conditions can differ within a neighborhood, especially next to a runway or heliport.
- Aircraft only: road, rail and other noise are not included.
- Flight patterns change with runway use, seasons and new routes. The score reflects the sampled year.
Advertisement
Data sources and credits
| What | Source | License |
|---|---|---|
| Flight tracks | adsb.lol globe_history | ODbL 1.0 |
| Aircraft registry | FAA Releasable Aircraft Database | US government, public domain |
| Airspace, training routes, airports | FAA Aeronautical Data Delivery Service | US government, public domain |
| State and county boundaries, places, population | US Census Bureau (cartographic boundaries 2023, Gazetteer, population estimates) | US government, public domain |
| Terrain elevation | AWS Terrain Tiles (USGS 3DEP/NED, SRTM and others; attribution) | Open data with attribution |
| Base map | Protomaps © OpenStreetMap contributors | ODbL 1.0 |
| Aerial imagery | USGS The National Map | US government, public domain |
| Address search | US Census Geocoder | US government, public service |
Open data notice
The noise grid behind this map is derived from adsb.lol flight data, made available under the Open Database License (ODbL 1.0). The derived noise database is available under the same license on request: hello@noiseabove.com.
Software
- MapLibre GL JS, BSD 3-Clause License.
- PMTiles and Protomaps basemaps, BSD 3-Clause License.
- Noto Sans fonts, SIL Open Font License 1.1. Map icons derived from tangrams/icons, MIT License.
- Turbo colormap by Google LLC, Apache License 2.0.