Down Syndrome, Turner Syndrome, RETT Syndrome, Klinefelter Syndrome. Down syndrome is a genetic chromosomal difference. In the simplest terms, while the number of chromosomes in an ordinary human body is 46, this number is 47 in individuals with Down syndrome because there are three 21st chromosomes. Down syndrome is not a disease that needs to be treated, it is a genetic difference. It has been determined that children with Down syndrome lag behind the developmental processes of healthy children by an average of 9 months. In terms of language development, it is known that they form simpler sentences than their peers in terms of content and sentence structure, and their language development is slower. There are also pronunciation errors during the speech of children with Down syndrome. Many children with Down's syndrome have a impaired ability to distinguish sounds, due to a malfunction in the so-called "auditory discrimination" function, which is caused by a fundamental problem with the brain's evaluation of sound signals from the ear.