Sound Power - Sound Power Measurement

Sound Power Measurement

A frequently used method of estimating the sound power level at a source is to measure the sound pressure level at some distance, and solve for :

$L_\mathrm{W} = L_\mathrm{p}-10\, \log_{10}\left(\frac{1}{4\pi r^2}\right)\,$ If the source is in free space

$L_\mathrm{W} = L_\mathrm{p}-10\, \log_{10}\left(\frac{2}{4\pi r^2}\right)\,$ if the source is on the floor or on a wall, such that it radiates into a half sphere.

The sound power estimated this does not diminish or increase with distance, unless reflections are present.

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