Clinical audiology is a relatively young science, yet much has already been published on highly complex questions such as cochlear physiology, psychoacoustics, psychology of hearing, electrophysiological data processing and aural rehabilitation. All this is written by doctors for doctors. Up to nothing has been written exclusively for the audiology technician, by a technician. The aim of this book is not to go into the relevance or the reliability of the various audioological procedures, but to offer a guide for the application as well as an understanding of their significance and interpretation, in order to be able to provide the physician with accurate and useful information on which to base appropriate therapeutic strategies. The figure of the audiology technician is present throughout Europe but there exist different levels of preparation and fields of action in the various countries. This book is an attempt to level out these discrepancies, offering an identical reference point for all levels. It is evident that it will cover too much for some and too little for others, but I hope that it will be used as a meeting point and help those who operate in this complex and fascinating field to enjoy their work and to get the best from the available equipment and, above all, from the patient.