This special issue of the Anatomical Record examines the relationship between structure and function in the auditory system. Early anatomical studies defined this relationship on a macroscopic level and described the roles of structures such as the tympanic membrane, ossicular chain, Eustachian tube, and cochlea. As new tools emerged, the microscopic structure of the organ of Corti was described and later the brain stem regions involved in auditory processing were identified. Further technical advances allowed the description of cells within these central auditory regions in both morphological and physiological terms. More recently, studies of the auditory system have employed molecular biological techniques and novel imaging protocols. All these techniques continue to provide important insights into the structure and function of the auditory system on gross, cellular, and molecular levels. This issue expounds on this theme by demonstrating the importance of anatomy, whether the shape of the otic capsule or the sequence of a gene, in determining the function of the system and even the phenotype of the organism. The articles in this issue represent the cutting edge of today's auditory science and look back at the evolution of hearing and balance, as well as forward toward improving cochlear implant outcomes and gene therapies for treating sensorineural hearing loss. Anat Rec Part A, 2006. © 2006 Wiley-Liss, Inc.