The speech of people who are dysfluent may be hard to understand, it may seem to be jerky or disjointed, and it does not flow easily from one word to the next. The idea is spoken The message is heard The message is understood People with Down syndrome may find some or all of these steps particularly difficult. As well as this, hearing loss, which is quite common in people with Down syndrome, makes learning and understanding language difficult. For all of us it is common to find that, as the pressure to speak and speak well builds, a breakdown in fluency may occur. The effect is as if the 'bottled up' air is escaping from the lungs in a rather uncontrolled fashion.
Fluent speech is dependent on a steady flow of air.
Emphasis being placed on the wrong word in a sentence or on the wrong part of the word. Sometimes it may be difficult for the person to start the voice working leading to sudden high pitched or loud sounds. This may lead to hesitant and unsure speech and to communication between the person with Down syndrome and the listener breaking down. Dysfluency occurs when demand exceeds capacities. There are many others that can be added.