Despite early diagnosis, early fitting of more advanced sensory aids, early intervention, and intensive educational management, many children with severe to profound hearing loss are delayed in their acquisition of spoken language compared with their peers with normal hearing. Some of the greatest challenges facing educators of deaf children include determining where to focus intervention in order to maximise benefit, and establishing the most effective strategies for the development of age-appropriate language. The experimental research in this book examined the relationship between hearing, speech production, and vocabulary knowledge, and investigated the contributions of these factors to the overall speech perception performance of deaf children. This research also investigated the areas in which intervention would be most beneficial, and examined the effects of different types of intervention on the development of spoken language and speech perception skills in deaf children. The evaluation, analysis and intervention methods reported in this book provide an experimentally validated program for improving speech perception, speech production and spoken language skills of deaf children.