The genetics of deafness is a rapidly expanding area of research. A remarkable total of twenty-two genes involved in non-syndromic deafness in humans have been localized within the past two years, compared with only one known previously. Some of the genes involved in neuroepithelial deafness, the most common type of pathology, have been identified in the past year. Two of these genes encode unconventional myosin molecules. The roles of these and other molecules identified by genetic approaches as important in hearing are being explored.