Developmental dysfluency, or "normal dysfluency", is a lack of language fluency that occurs during early childhood development. It is commonly observed in children ages 2 to 4 years old. This typically occurs as they begin to learn language and communication skills. Developmental dysfluency refers to speech that is continually interrupted rather than flowing naturally. Developmental dysfluency is most commonly expressed through inconsistencies in speech such as stuttering, repetition, lengthening of sounds and syllables, mistiming, and poor inflection.Speech is a complicated skill involving a series of cognitive and linguistic processes that are both sensorimotor and auditory. As children grow, their language and vocabulary grow exponentially. Dysfluencies in early speech are typical as their speech skills develop. The most common form of dysfluency in children younger than three years is the repetition of one-syllable words or parts of words. Words or syllables are often repeated in the beginning of their sentences as they try to process how to form the rest of the sentence. Language dysfluency may be common in children as they learn basic language skills throughout the crucial development stages in early childhood. Developmental dysfluency is normal in children as they work to acquire language skills and semantic/syntactic processing. About twenty-five percent of children experience some loss in fluency in their linguistic abilities. Some children between the ages of 2 and 6 encounter some obstacles in the path to fluent speech. Fluency in a normal child will typically improve around the age of 4. When attempting to master spoken language, children gradually develop fluent speech.
Those with these types of dysfluencies will exhibit the afore mentioned repetitions about once every 10 sentencesMistiming and stuttering are common ways that developmental dysfluency manifests itself. When a child mistimes, they prolong a certain letter/syllable in the word they are saying, thereby taking much longer for their sentence to be said. Pauses or blocking are another side effect relating to developmental dysfluency. This is when one inserts a silent interval within the word. Revision is similar to this but is the halting completely, mid-flow of a sentence and taking the thought in a different direction. There is evidence to show that this may not only be an issue of speech motor areas but also the auditory cortex. In a MEG study by Beal et al. they found that adults with "persistent developmental stuttering" or PDS, had slower cortical timing than those who spoke completely fluent. This shows us something is wrong in their auditory motor integration. As far as the underlying ailments behind stuttering, It is not well known whether this side effect has to do with "errors in linguistic planning" or issues with "access or retrieval of linguistic elements" and it could very well involve both issues.On occasion, children will go beyond the normal dysfluency patterns. Instances like the previously mentioned example indicate that the child is learning to use language. In contrast, children with stuttering disorder, will likely repeat sounds or one-syllable words three or more times. They may also prolong sounds for two or more seconds.