It is a section of special psychology that studies the mental development of the deaf and hard of hearing, and the possibilities of hearing correction in conditions of education and upbringing. S. explores ways to prevent mutism in people with hearing defects that rule out normal speech communication. It determines the characteristics of their cognitive activity, It illustrates the compensatory possibilities for replacing auditory perception with visual perception, and sensations of vibration, etc., It studies the characteristics of thinking, Memory and other mental processes that are formed in conditions of absence or retardation of auditory sensations. Data registration is a necessary condition for organizing the education and upbringing of deaf and hard of hearing children.