Hearing problems in children hard of hearing, in addition to communication skills, will effect social interaction too. One aspect of social recognition which has attracted an increasing attention in recent years is the development of children's intelligence theory. In connection with intellectual and recognition abilities in children hard of hearing, intelligence is a subject that has always been at the center of attention, especially the important role of visual intelligence in memorization and recognition related to the important communication tools such as lip reading, sign language and cued speech. The results of the studies indicate that children's low performance in children hard of hearing in recognition abilities such as Intelligence Quotient and mental theory are mostly related to the dependence of these abilities on the evaluation or the measurement of verbal skills. However, the usage of non-verbal assessment tools and based on the type of measurement related to manual skills (such as pointing language) these children'[s grades have improved greatly and little difference has been seen compared with the grades of normal children in the field of Intelligence Quotient. However, when it comes to visual memory, in most researches, there was a difference in favor of normal children versus those who were hard of hearing. In this article, we will analyze these issues in detail.