About NoiseCheck postcode values
Last reviewed: 12 October 2026
How the values are assigned
NoiseCheck assigns illustrative decibel values to postcode districts using lookup groups for airports, motorways, railways and industrial areas. A postcode's group membership selects which source categories are included. The generator uses a postcode-derived hash to assign values within preset ranges. Ambient values are assigned from an urban or rural category and another preset range.
When population data is missing, the generator uses a fallback population category to select an urban or rural classification. It adds preset industrial values for urban and suburban areas without an explicit industrial lookup. It also caps road, rail, aircraft and industrial values for configured quiet-area prefixes, and applies road and industrial floors to configured city-centre postcodes.
The assigned values for the source categories are combined to create an overall value. The output is a repeatable illustration produced by the site's code, not a survey, noise contour or location-specific acoustic model. Town, county and national rankings are sorted from those same assignments.
What these values are not
These values are illustrative and not measured or validated predictions. They are not suitable for property, legal or health decisions, and they cannot tell you what you would hear at a particular address, indoors or outdoors.
For a professional noise survey, use the Association of Noise Consultants member directory.
Official noise maps
Official maps use their own sources, coverage, methods and noise metrics. Check each publisher's notes before comparing data with NoiseCheck's illustrative values.