Mainly used by deaf people for effective communication; lip reading is following the lip movements of a speaker to understand what he or she is saying. For this reason it is also known as speech reading. As well as the lips, the movements of the tongue, the jaw, the eyes, the face, the hands and the body are also followed. Knowing the context in which the speaker is speaking makes it easier for a deaf person to fill in the gaps about what is being said. Ever since it was first used to rehabilitate injured WWI soldiers, lip reading has been taught in many schools for the deaf.