# Industrial Noise Reduction

## Calculating Noise Level at various distances from the source

The equation is:

L(r)=Lo-20log10(r/ro)

where:

r0 is the noise level at distance L0 & L is the level at r

Therefore if you know the noise level at 3 feet (or any distance) you can calculate the noise level at other distances with this equation.

Example:

Suppose you know that the blower is at a level of 95 dbA at 3 feet and you want to know what it is at 10 feet.

L(r)=95-20log10(10/3)

L(r)=84.5 dbA

This equation assumes that there are no major reflecting surfaces nearby. This equation is known as the “inverse square law field”.

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