Articulation Disorder or Phonological Disorder? What is the Difference?
September 9, 2016 Speech & OT of North Texas

Articulation Disorder or Phonological Disorder? What is the Difference?

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A child’s verbal speech intelligibility is one of the most common referral reasons for speech therapy. By 2 years of age, a child’s speech should be 50% intelligible to an unfamiliar listener, by 3 years of age 75% intelligible to an unfamiliar listener and by 4 years of age 100% intelligible to an unfamiliar listener. When considering these percentages, it is important to keep in mind that they are based on how intelligible a child is to adults who do not interact with the child on a consistent basis (i.e. not parents, siblings, neighbors, teachers or anyone else who your child may regularly see). Familiar listeners (especially parents) are going to be more desensitized to errors in the child’s speech(and sometimes will even correct the errors silently as they listen without even noticing) and they are going to havemore general context of what a child is talking about, which will increase overall intelligibility.

Speech sound disorders can be broken down into phonological disorders and articulationdisorders. It is very important that speech sound disorders be diagnosed appropriately, as treatment for phonological and articulation disorders differ. Articulation disorders manifest when a child has difficulty producing a specific sound (or sounds) and are remediated by addressing the sound(s) in error. Phonological disorders are more complex, as they are patterns in a child’s speech used to simplify speech sound production. The majority of children with highly unintelligible speech present with a phonological disorder, as their speech is characterized by repeating patterns of incorrect productions. New talkers and toddlers frequently utilize phonological processesas they develop and expand their speech.Some of these patterns may include replacing a harder sound with an easier one (substitution),simplifying syllables (syllable structure) and altering sounds due to the influence of a neighboring sound (assimilation).Just like some speech sound errors are developmentally appropriate for a child’s age, some phonological processes are developmentally appropriate. For example, final consonant deletion is developmentally appropriate in the speech of a 2-year old although not in the speech of a 5-year old.

Although not every child will utilize phonological processes as they develop speech, many children will rely on these patterns until they are able to produce the more difficult patterns and speech sound combinations. Phonological processes become a concern when a child continues to utilize the process to simplify speech past the time when it is considered developmentally appropriate. Some phonological processes are considered atypical, as they are not phonological processes frequently used in developing speech (for example, it is common for toddlers to drop the final consonant in words although it is not common for them to delete the initial consonant in words).

The chart below contains frequently seen phonological processes, although this list is not exhaustive.

Phonological Process Description Example
Fronting replacement of a sound typically produced in the back of the oral cavity (velar or palatal sounds), with a front sound (alveolar sound) “tar” for “car”, “tandy” for “candy”
Backing replacement of a sound typically produced in the front of the oral cavity (alveolar sounds) with a back sound (velar or palatal sounds) “gog” for “dog”
Final Consonant Deletion omission of final consonant “cu” for “cup”
Cluster Reduction simplification of a cluster into single sound “poon” for “spoon”
Weak syllable deletion deletion of weak syllable in word “tefone” for “telephone”
Gliding liquid sound (/r/ and /l/) replaced by glide (/w/ and “j”) “wadder” for “ladder”
Stopping replacement of fricative or affricate with stop sound “too” for “shoe”
Reduplification repetition of syllable “wawa” for “water”
Prevocalic Voicing replacement of voiceless consonant with a voiced consonant “vone” for “phone”
Initial Consonant Deletion deletion of initial consonant “ose” for “nose”
Epenthesis addition of schwa (“uh” sound) in between two consonants “puh-lane” for “plane”

The following processes typically remediate prior to the age of 3:

Final Consonant Deletion
Weak Syllable Deletion
Prevocalic voicing

The following processes typically persists past the age of 3:

Cluster Reduction
Prevocalic voicing

The following processes not considered to be a typical part of speech sound development:

Initial Consonant Deletion

If your child’s speech is difficult for less familiar listeners to understand and/or you feel that your child may have a phonological disorder, please contact Speech & Occupational Therapy of North Texas at 972-424-0148 to schedule an assessment with a speech-language pathologist. With intervention, children with phonological disorders typically make tremendous progress towards their goals and significantly increase their overall intelligibility.

We provide pediatric occupational therapy and speech therapy in McKinney, Plano, and Frisco and are network providers for most major insurance plans.


Bowen, C. (2011). Table 2: Phonological Processes. Retrieved from www.speech- on July31, 2016.

Hanks, Heidi. “What are Phonological Processes?”.Mommy Speech Therapy. Accessed August 1, 2016.

“What Are Phonological Processes?”.Super Duper Handy Handouts. Accessed August 1, 2016.