Book excerpt: The cochlear implant is a device that bypasses a nonfunctional inner ear and stimulates the auditory nerve directly. Written by the "father" of the multi-electrode implant, this comprehensive text and reference gives an account of the principles underlying cochlear implants and their clinical application. For the clinician, the book will provide guidance in the treatment of patients; for the engineer and researcher it will provide the background for further research; and for the student, it will provide a through understanding of the subject.