Sound Attenuation Calculator – Line Source

How do I calculate the attenuation of sound from a line source?

A line source generates sound that spreads cylindrically. This means that for every doubling of distance, the sound energy is spread across double the area and the sound intensity halves. Examples of line sources could include compressor pipes, a train or even a busy road to name a few.

Use the calculator below to calculate the attenuation of sound from a line source.

See our popular inverse square law calculator to calculate the free-field attenuation of a point source.

What is Sound Attenuation?

Attenuation is the reduction in sound intensity as it travels from a source to a receiver.

Factors that influence attenuation of sound outdoors include:

  • Geometrical spreading (as sound travels away from the source),
  • Atmospheric absorption, and
  • Excess attenuation which includes reflection, diffraction and refraction.

The most significant factor in the attenuation of sound is geometrical spreading. Therefore simplified methods of attenuation estimation often consider only attenuation due to geometrical spreading. For more information on the propagation and attenuation of sound outdoors, please visit Simon Fraser University.


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.