In planning The Handbook volumes on Audition, we, the editors, made the decision that there should be many authors, each writing about the work in the field that he knew best through his own research, rather than a few authors who would review areas of research with which they lacked first hand familiarity. For the purposes of the chapters on Audition, sensory physiology has been defined very broadly to include studies from the many disciplines that contribute to our understanding of the structures concerned with hearing and the processes that take place in these structures in man and in lower animals. A number of chapters on special topics have been included in order to present information that might not be covered by the usual chapters dealing with anatomical, physi ological and behavioral aspects of hearing. We wish to thank all authors of the volumes on Audition for the contributions that they have made. We feel confident that their efforts will also be appreciated by the many scientists and clinicians who will make use of the Handbook for many years to come. WOLF D. KEIDEL WILLIAM D. NEFF Erlangen Bloomington August 1974 Contents Introduction. By G. v. BEKESY t. With 3 Figures… … . . 1 Chapter 1 Consideration of the Acoustic Stimulus. By R. R. PFEIFFER. With Chapter 2 19 Figures… … … … … … … … . 9 Comparative Anatomy of the Middle Ear. By O. W. HENSON Jr. With Chapter 3 23 Figures… … … … … … … . . 39 … . .