While keeping the scope and essential thrust of the original book unchanged, this third edition has been updated to reflect the latest technology. For instance, important revisions have been made to a few chapters, while one chapter has been eliminated and replaced with a newer chapter dealing with recent developments in digital and consumer electronics that are relevant to laboratory instrumentation. The authors hope the readers of this text will be more confident with instrumentation and more willing to experiment with it, as well as be able to appreciate the possible ways that electronic instrumentation can be used in their work. The book was written with the undergraduate in speech and hearing sciences uppermost in mind. Instead of detailed information about individual pieces of instrumentation, a more basic and broad descriptive approach has been used. Throughout, examples have been provided regarding how certain pieces of equipment can be used in the clinic or laboratory. One or more step-by-step exercises are included at the end of certain chapters to help students obtain hands-on experience and equipment flowcharts help reinforce the exercise. Students who complete this book will have a basic understanding of the major pieces of instrumentation in the hearing and speech clinic/laboratory.