<div class="htmlview paragraph">We are basically interested in Sound Intensity whenever we deal with sources of sound in noise control. The development of techniques and new tools for the direct measurement of the flow of acoustic energy offer new ways for determination of source location, source ranking, energy flow path and absorption measurements. Optimum microphone probe configurations for different applications, digital processing and data presentation will be discussed. The use of true real time data processing in collection of energy flow data in mechanical structures is suggested as a new tool for the mechanical design engineer.</div>