*BIOSONAR a new book edited by Annemarie Surrlyke, Paul E. Nachtigall, Richard R. Fay and Arthur N. Popper has just been released by SPRINGER in its ongoing series of Handbooks on Auditory Research. Bats and odontocetes have evolved the ability to use echolocation to find objects in their environments. And, despite there being substantial differences in their environments, there are substantial similarities, as well as any number of fascinating differences, in how members of these two groups produce, use, and process biosonar signals. chapters are written by experts from both animal groups, resulting in collaborations that examine not only data on bats and odontocetes, but also compare and contrast mechanisms and what is known. In effect, the chapters provide a unique insight that will help push forward our understanding of biosonar in both groups..* -- Paul Nachtigall, PhD Hawaii Institute of Marine Biology' 808 247 5297