ABSTRACT
Sometimes signals are too weak and must be made stronger; sometimes they are too strong and must be reduced. Sometimes more than one signal must be sent to one input of an instrument and sometimes not all of the spectrum of the signal is important or wanted. These situations call for an understanding of very basic “workhorse” type instrumentation. In this chapter we discuss amplifiers, attenuators, mixers, and filters, which are frequently used in the speech and hearing clinic or laboratory to condition and shape the signal and to route it to a particular place.
