Sound Power Determination based on Minimum Measurement Data using a Three-Dimensional Sound Intensity Measurement System

Abstract The sound power level can be calculated from the peak sound intensity level, the distance from the observation point to the source, and the directivity index. For the sound power determination based on minimum measurement data, this report discusses whether the directivity index can be theoretically calculated from the maximum directivity ratio, the beam width, and the surface area of minor lobes using model sound sources. A 3-D sound intensity measurement system can easy measure these quantities. As the results, it can be said that the directivity indices can be obtained from five curves (ln models)