Speech output in boys is often reported to be fast and cluttered. Because many children with fragile X have extreme sensitivity to touch, oral-motor stimulation is often difficult. Articulation of some of the later developing sounds may be more difficult and require speech therapy. Both vowels and consonants are reported as problematic to some children, with substitutions of sounds being common. Cluttering is a characteristic that is often used to describe the speech of boys with fragile X syndrome.
Cluttered speech is fast in rate, with a mixture of short, rapid bursts of speech and long pauses.
There are repetitions of whole words or phrases. In addition, many of those who clutter do so without awareness or accompanying tension. Voice problems in boys with fragile X are sometimes reported. Vocal characteristics such as hoarseness, harshness, and breathy tone may be related to oral-motor weaknesses. All of these factors may contribute to lowered intelligibility of boys' speech.