ABSTRACT
The first step in any systematic approach to noise control requires that the spectral character of the sound or noise be determined. The two physical properties which are easily measured and will suffice in most cases of industrial noise control are sound pressure and frequency. However, because of the wide range of variation of both, logarithmic and geometric scales were created to condense the range and to generally simplify computations. This chapter develops a working knowledge of these scales and bring together several other physical parameters essential to characterizing sound and noise sources. In final summary, the chapter have defined the basic physical parameters which, in most cases, will suffice to characterize industrial noise. In addition, simple analytical methods were developed to deal with these parameters, and they were illustrated with numerous commonly encountered examples. With this background, the chapter proceeds directly to more practical applications.
