Synopsis Most of the disorders, whether physical or mental are genetic or they develop due to lack of proper care on the part of the parents or due to poor food. Those children who are hard of hearing or have become totally deaf cannot be fully educated in the normal course. Some children can improve their power of hearing by using devices, but deaf children who are usually dumb also have to be educated through special methods of education. This book specifically dwells on the methods and techniques of educating the deaf and the dumb and those who are hard of hearing.