Evaluation of the intensity method of sound power determination

Abstract

If the sound power of a source is obtained by forming the surface integral of the normal component of the sound intensity vector, the shape of the surface of measurement is unimportant and projection error only occurs as a result of nonideal polar response of the composite microphone. Furthermore, the sound power of the source may be determined selectively in the presence of background noise originating outside the closed surface. If a sufficient number of points of measurement are taken, the error depends mainly on the signal−to−noise ratio at each point and on the accuracy of the measuring system. Subject Classification: 50.25, 50.85.