Book excerpt: The extraordinary ability of dolphins to echolocate has fascinated scientists and the public since its discovery in the late 1950's. This is the first book to summarize modern research in this area, and presents a broad synthesis of this very interdisciplinary subject. The author is an internationally-recognized expert on dolphin sonar and is thus in a unique position to bring together research on the physiological, mathematical and engineering aspects of the subject. Of interest to auditory researchers, electrical engineers, acoustical physicists, and mammalian physiologists.