Speech sound disorders is an umbrella term referring to any difficulty or combination of difficulties with perception, motor production, or phonological representation of speech sounds and speech segments—including phonotactic rules governing permissible speech sound sequences in a language.

Speech sound disorders can be organic or functional in nature. Organic speech sound disorders result from an underlying motor/neurological, structural, or sensory/perceptual cause. Functional speech sound disorders are idiopathic—they have no known cause. 

Organic Speech Sound Disorders

Organic speech sound disorders include those resulting from motor/neurological disorders (e.g., childhood apraxia of speech and dysarthria), structural abnormalities (e.g., cleft lip and other structural deficits or anomalies), and sensory/perceptual disorders (e.g., hearing impairment).

Functional Speech Sound Disorders

Functional speech sound disorders include those related to the motor production of speech sounds and those related to the linguistic aspects of speech production. Historically, these disorders are referred to as articulation disorders and phonological disorders, respectively. Articulation disorders focus on errors (e.g., distortions and substitutions) in production of individual speech sounds. Phonological disorders focus on predictable, rule-based errors (e.g., fronting, stopping, and final consonant deletion) that affect more than one sound. It is often difficult to clearly differentiate between articulation and phonological disorders; therefore, many researchers and clinicians prefer to use the broader term, “speech sound disorder,” when referring to speech errors of unknown cause. See Bernthal, Bankson, and Flipsen (2017) and Peña-Brooks and Hegde (2015) for relevant discussions (www.asha.org).

Articulation Disorders

An articulation disorder involves difficulty correctly pronouncing consonant and or vowel sounds. Spoken sounds can be deleted, substituted, added, or changed. These errors make it difficult – if not impossible – for people to understand your child’s meaning, in which case the speech is deemed “unintelligible.” Speech-language pathologists use the term “unintelligible” to describe a child who cannot be understood by both family members and acquaintances.

How to identify an Articulation Disorder

As children learn to speak and acquire new sounds from the ages of one to five, a certain amount of articulation errors is a natural part of the process. However, should these speech patterns continue beyond the expected age of mastery, a speech-language evaluation is necessary. When familiar and unfamiliar listeners struggle to understand your child’s speech or your child exhibits frustration or avoidance around communicating or repeating sounds, your child may be struggling with articulation. Here are some of the red flags to look for in your child’s speech development that may suggest an articulation disorder is present.

    • Omissions – Leaving out essential sounds from a word (For example: saying /tee/ instead of /tree/.)
    • Substitutions – replacing sounds with similar – but incorrect – sounds (For example: saying /fith/ instead of /fish/.)
    • Distortions – mispronouncing sounds (For example: saying /sock/ with a distorted /s/ sound that cannot be clearly distinguished as another sound.)
  • Additions – adding an unnecessary sound to an appropriately pronounced word (For 


A trained Speech Language Pathologist will consider all of the above criteria during a speech evaluation, which is the first step in determining whether your child’s misarticulations are the result of an articulation disorder, or a symptom of an underlying Myofunctional Disorder. Treatment of an articulation disorder varies according to how the disorder manifests itself in speech, but it often involves isolating the problematic phoneme (unique sound), practicing production of that sound, and then practicing the sound in context.

As children grow, their speech and language habits become deeply engrained, meaning that the longer their mispronunciation goes unaddressed the harder it is to correct. While parents may smile as their child sweetly says /wabbit/ instead of /rabbit/, ultimately the child needs to be taught to produce the sound correctly before the habit becomes permanent.

Phonological Disorders

A phonological disorder is a type of speech sound disorder in which a child uses patterns of sound errors. For example, a child may use a specific error pattern in his/her speech such as changing all “b” sounds to “p” sounds. So, the child would produce “ball” as “pall” and “cab” as “cap”. Specific error patterns, like the one above, are referred to as phonological processes.

While it is appropriate for children to use specific phonological processes in the early years, these error patterns are expected to disappear at certain ages. Oftentimes, overuse of these sound error patterns will make it difficult for parents, other children, and educators to understand your child.

Identifying Phonological Disorders

Some of the most common symptoms experienced by children with phonological disorders include:

  • Use of patterns of sound errors (ex. always substituting “p” for “b” or “w” for “l”)
  • Having trouble saying multisyllabic words
  • Having trouble saying sentences
  • Not being understood


Given that developmental speech millstones are only moderately trustworthy, it can be tempting to believe that a phonological disorder will simply go away on its own, or that your child will “grow out of it.” The truth is that seeking early intervention can prevent a phonological disorder from worsening and that there is no harm in bringing your observations to the attention of your child’s pediatrician or speech language pathologist. A simple speech evaluation involving several tests can determine the type and severity of a phonological disorder if one is present. If indeed your child has a phonological disorder, professional speech therapy is necessary, and a qualified speech language pathologist will create a personalized treatment plan to address your child’s specific disorder and circumstance.

Successful treatment for phonological disorders focuses heavily on the increasing a child’s awareness to the speech errors, practicing correct production of sounds by watching the speech therapist’s mouth, using a mirror to watch his/her mouth, and touching of the face and mouth at times to help shape the mouth appropriately.

The goal of speech therapy for children is to enable clearer speech and the confidence necessary to employ their new skills in the context of everyday life.