ABSTRACT
Active noise and vibration control can be viewed as a specialised section of the larger field of automatic, or feedback, control. Here, some general background theory from this field, which will be pertinent to the later specialised discussions, will be considered. The work discussed here is relevant mainly to feedback noise and vibration control systems; most of the necessary background for feedforward systems is found in Chapter 6. The difference between the two, and the reasons for choosing one over the other, is discussed in this chapter, as well as in Chapters 1 and 6.
