Speech intelligibility of adults with Down syndrome

Communication is one of the basic human needs and important paths to independence of each individual, including those with Down syndrome (hereinafter DS). The biggest derogations in the communication skills of people with DS are in the speech and language area. Poor speech intelligibility disables efficient communication and social inclusion, limits academic and vocational, and influences the psychological and emotional development of an individual's life. Research in the field of speech and language development of people with DS only included children in the past, since the life expectancy of these individuals was very short. With the increase of life expectancy (up to 50 years and more) there is a need to explore this development of adults with DS as well and consequently prepare them to live independently as far as possible. An important factor here is efficient communication the crucial prerequisite of which isspeech intelligibility. According to different authors, speech and language skills of individuals with DS can improve with therapy in the adulthood as well. Therefore, with this research, we would like to point out that adults with DS should be given the support of speech and language therapists as well to ensure maximum development and preservation of acquired speech and language skills. The theoretical part of the master's thesis concerns the explanation of the terms DS, intellectual disability (hereinafter MDR), communication, speech, speech and language development, speech and language disorders, and speech intelligibility as well as the description of communication, speech, language and speech intelligibility characteristics of people with DS. Interaction between motoric functions and speech of these individuals is also described. The research included 149 individuals with DS from various parts of the country. Our goal was to gain insight into speech intelligibility of adults with DS in Slovenia which has not been the subject of research thus far. The data were collected through a questionnaire which included Intelligibility in Context Scale (ICS): Slovenian (hereinafter ICS Scale) and some additional questions referring to speech intelligibility as well as speech and language difficulties. We were interested in the degree of speech intelligibility according to different communication partners and factors that might influence it (gender, age, hearing, speech, language difficulties etc.). The survey has shown that adults' speech intelligibility is better in situations where the communication partners are more familiar with each other (they are close to each other and spend more time with each other). Therefore, these individuals are best understood by their parents/guardians and least by unknown people. The results also indicate that speech intelligibility decreases with the increase of mental disorder. Speech of individuals with mild MD is better understood than the one of people with severe MD. Their speech intelligibility is also affected by hearing, speech and language problems. Speech intelligibility of individuals that don't have these difficulties is better than of those that have them. However, there is no significant difference between genders regarding speech intelligibility. It was also established that the majority of adults with DS are experiencing difficulties due to poor speech intelligibility in unknown situations. Since they are less intelligible, they function better in familiar settings and known environment with people they know than in unfamiliar settings surrounded by strangers. However, the results have also shown that individuals who experience difficulties in familiar settings are less intelligible than those who struggle in unfamiliar settings. Communication difficulties in familiar settings and home environment are detected later than in unfamiliar settings, since people who spend the majority of time with the child/protege are used to his way of speaking and better understand his speech