ABSTRACT
In this chapter it will be shown how the quantities, sound pressure level, sound intensity and sound power are related. Sound pressure level is the quantity most directly related to the response of people and things to airborne sound and this is the quantity that is most often to be controlled. However, sound pressure level is not always the most convenient descriptor for a noise source, since it will depend upon distance from the source and the environment in which the sound and measurement position are located. A better descriptor is usually the sound power level of the source (see Section 1.8).
