Through the generosity of the South West Metropolitan Regional Hospital Board a research unit for the study of apparently deaf children with defective speech was set up in Belmont Hospital in March, 1953. The primary object of the unit is to attempt to assess by methods which will be discussed later whether children who have acquired no speech are in fact only deaf or whether they are mentally defective, emotionally disturbed, or are suffering from these or other conditions. It is an undoubted fact that some children who have never spoken and who are therefore inaccessible and who may be asocial or antisocial in their behaviour are diagnosed as being mentally defective and spend their lives in mental defective institutions. It has however already been shown in our unit that a number of these children when under observation for a period of time prove to be deaf and probably educable. If facilities were available to continue their education under specialized conditions they could no doubt make useful citizens within their limitations. Before discussing the problems associated with these children in more detail it might be as well to describe the personnel and layout of the unit.