NOISE POLLUTION
Noise Standards :
Type of Area
Night (dB)
Day (dB)
Sensitive
40
50
Residential
45
55
Commercial
55
65
Industrial
70
75
Noise : Noise is unwanted Sound .
Sound is measured in terms of Sound Pressure Level (SPL) and expressed as decibel (dB) .
SPL , L = 20 log10 (P/P0)
where ,
P = pressure in Pa
P0 = reference pressure ( 20 Pa )
Sound can be sensed by humans when Sound Pressure Pa
Conversion Note : 1 bar = 105 Pa
1 bar = 105 Pa
SPL at two positions :
L2 = L1 – 20 log10 ( R2 / R1 )
R1
R2
Equivalent Noise and Average Noise :
A source (or sources) emitting different sounds at different time periods .
Equivalent Noise ,
Leq = 10 log10
Noise Standards :
Type of Area
Night (dB)
Day (dB)
Sensitive
40
50
Residential
45
55
Commercial
55
65
Industrial
70
75
Noise : Noise is unwanted Sound .
Sound is measured in terms of Sound Pressure Level (SPL) and expressed as decibel (dB) .
SPL , L = 20 log10 (P/P0)
where ,
P = pressure in Pa
P0 = reference pressure ( 20 Pa )
Sound can be sensed by humans when Sound Pressure Pa
Conversion Note : 1 bar = 105 Pa
1 bar = 105 Pa
SPL at two positions :
L2 = L1 – 20 log10 ( R2 / R1 )
R1
R2
Equivalent Noise and Average Noise :
A source (or sources) emitting different sounds at different time periods .
Equivalent Noise ,
Leq = 10 log10
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