This book deals with the way that the auditory system processes acoustic signals. The current edition has been revised in all areas to reflect the progress that has been made since the 3rd edition. As well as dealing with the basic anatomy and physiology of all stages of the auditory system, the book relates basic physiological processes to the performance of the auditory system as a whole, in the perception of acoustic signals including speech. The chapter on sensorineural hearing loss not only describes the physiological and anatomical changes that are associated with hearing loss, but includes latest information on treatments including cochlear implants, and work being undertaken on stem cell and other cellular therapies for deafness. A reading scheme has been provided to guide readers to the section most appropriate for their interests. The book is written so that those entering auditory research from very little background in auditory neuroscience are able to understand the current research issues and the current research literature. It is also intended to be a source book and reference work for advanced undergraduates studying the special senses, and for clinicians in the specialty of Otorhinolaryngology.