Outdoor ambient sound pressure levels (dBA) in rural and urban business and industrial environments with or without limited traffic.
In residential areas most noise comes from transportation, construction, industrial, and human and animal sources. Road traffic noise is the major source of noise.
The noise can be highly variable. It is common that Day-Night sound levels - Ldn - in different areas may vary a range of 50 dB. The outdoor level - Ldn - in a wilderness areas may occur as low as 30-40 dBA compared to 85-90 dBA in a urban areas. Most urban dwellers lives in areas of Ldn more than 48 dBA.
The table below indicates common outdoor sound pressure levels in rural and urban environments at the different octave bands.
|Outdoor Sound Pressure (dB)|
|Conditions||Octave Band Center Frequency (Hz)|
|Rural, no nearby traffic of concern||42||37||32||27||22||18||14||12|
|Suburban, no nearby traffic of concern||47||42||37||32||27||23||19||17|
|Urban, no nearby traffic of concern||52||47||42||37||32||28||24||22|
|Business or commercial area||57||52||47||42||37||33||29||27|
|Business or commercial area||62||57||52||47||42||38||34||32|
|Industrial or manufacturing area||67||62||57||52||47||43||39||37|
|Within 300 ft (91 m) of continuous heavy traffic||72||67||62||57||52||48||44||42|