ABSTRACT
Sources of sound generation are generally quite complicated and often beyond the capability of ordinary analysis if a detailed description is required. Fortunately, a detailed description of the noise-generation mechanism is often not necessary for noise-control purposes and in such cases very gross simplifications will suffice. For example, a source of sound of characteristic dimensions much less than the wavelengths it generates can often be approximated as a simple point source of zero dimension. In this case the properties of the idealized point source of sound will provide a sufficient description of the original sound source.
