The ear is an intricate structure whose anatomy and function has fascinated scientists since antiquity. Progress in our understanding of the cellular and molecular bases of the physiology of hearing has been quite impressive by the end of the 20th century. The development of the complexity and precision of the inner ear during embryogenesis is an extraordinary task. The field of ear development has followed the pace of other areas of developmental biology in trying to understand how this occurs at the cellular and molecular level. It is commonplace to relate the enormous progress in developmental biology to the explosion of DNA recombination techniques, the access to genetic manipulation of organisms, the import of ideas from fly development into vertebrate studies and, more recently, our knowledge of whole genomes.