Noise Barrier Effectiveness Calculator

Environmental Impact Assesment South Australia Environmental Consultants WKC Group

This online noise barrier effectiveness calculator can be used to approximate the resultant noise level at a receiver when a barrier is positioned with a pre-determined height between a noise source and a receiver (i.e. a person). The noise barrier (sometimes called an acoustic barrier, noise wall or sound barrier) attenuation is primarily a function of the source, receiver and barrier heights as well as the distances between them.

For ease of use, this is a simplified calculator with the following assumptions applied:

  • Reflections from facades or the ground are not considered
  • Air absorption is not considered
  • Directivity of the noise source is not considered
  • The diffraction limit is set at 20 dB

The tool uses the following formula:

Lp = Lw – 20log(r) – 11 – b


Lp = Sound pressure level 1m from receiver

Lw = Sound power level of noise source

r = Distance between source & receiver

b = Attenuation due to the barrier

A very useful interactive sound barrier tools is available online at You may also like to see our inverse square law calculator. For a complete tools list, see our side bar to the right.

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Please note that this or any other calculators on the tools room are for information only. WKC Group has endeavoured to ensure that the information presented here is accurate and that the calculations are correct, but will not accept responsibility for any consequential damages, faults or human errors that may arise from the use of formulas, inventories and values