Language and Speech Development in Children with Down Syndrome
Delayed or impaired speech and language development in children with Down syndrome has been reported in many studies. This delay and disorder usually occurs in the early period. Since Down syndrome can be detected before birth, parents know that their children will be delayed in terms of communication and language. This information enables parents of children with Down syndrome to intervene as early as possible. Communication development starts from birth (Roberts et al., 2008).
Language comprehension skills in children with Down syndrome progress in line with their non-verbal intelligence development. Considering the expressive language development, especially the first words can be at the expected level; however, it is seen that there are delays in the development of both vocabulary and syntax in expressive language in the following periods. As a result, receptive languages are more advanced than expressive languages (Kürkçüoğlu, 2009).
Although there is wide individual variation in children with Down syndrome, they often say their first words later than normal children, and their vocabulary develops later. At the same time, they have difficulty in forming grammatical sentences. However, telegraphic speech tendency and poor pronunciation in children with Down syndrome reduce their intelligibility, especially when speaking to strangers.
Studies have shown that children with Down syndrome lag far behind healthy children in terms of language development. According to Fraser (1978), children with Down syndrome use their first words between the ages of 1 and 6, and short sentences at the age of 5 on average. Smith (1977) found that children with Down syndrome lag behind the developmental processes of healthy children by an average of 9 months. In addition to this determination, Nöther (1981) states that children with Down syndrome not only lag behind healthy children in terms of developmental process, but also form simpler sentences than their peers in terms of content and sentence structure (Buckley, 1993).
The speech of children with Down syndrome is often incomprehensible. These children’s other language skills, such as comprehension, are better than speech skills compared to children without Down’s syndrome and mental retardation. While some researchers claim that the speech of children with Down syndrome is only delayed, some researchers also claim that the speech of children with Down syndrome is not only caused by cognitive impairment; They claim that the characteristics of Down syndrome also play a role (Dodd & Thompson, 2001).
Phonological Development in Children with Down Syndrome
Differences in speech sound development for children with Down syndrome begin with the transition to the first word. Before that, no difference was observed with their normal peers. Children with Down syndrome have consonant errors as well as phonological operations similar to those of normally developing children at a similar mental level. Speech errors are common in preschool and older children with Down syndrome. In addition, children with Down syndrome have auditory short-term memory difficulties and their speech intelligibility is low due to phonological errors (Kürkçüoğlu, 2009). In addition, most of the children with Down syndrome suffer from hearing loss due to otitis media and/or middle ear anomalies from the early period. Studies conducted with normal newborns who have had otitis media show that otitis media negatively affects the language and speech development of these children, even in the prelinguistic period (Stoel-Gammon, 1997).
Stoel-Gammon, (1997) suggests that children with Down syndrome have the same patterns as children who develop normally in phonological acquisition, with four exceptions.
1) It is moving at a slow speed.
2) It shows much more variety.
3) Specific and atypical error rates are high.
4) The acquisition of suprasegmental aspect of speech is different. This difference is probably due to the low intelligibility of speech reported in Down syndrome patients.
Roberts, EJ,Chapman, RS, Warren, SF, Speech and language development and intervention in Down syndrome and fragil x syndrome, Paul H. Brookes Publishing Co., Baltimore London, 3-54, 2008.
Kurkcuoglu, U. B., Development of communication skills, Batu ES, (Ed.), Children with Down syndrome between the ages of 0-6 and their development (1) (263-266), Ankara. Root publishing, 2009.
Buckley, S., Language development in children with down syndrome, the down syndrome Educational Trust Down Syndrome Research and Practice, volume 1, 3-9 (1993).
Dodd, B., Thompson, L., Speech disorder in children with Down’s syndrome, Journal of Intellectual Disability Research, 45, 4;308-316 (2001).
Stoel-Gammon, C., phonological development in down syndrome, Mental Reterdation and Developmental Disabilities Research Rewiews, 3: 300–306 (1997).