Phonological Impairments

Phonological Impairments

What is a phonological disorder?

Phonological disorders are a type of speech sound disorder. Phonological disorders are characterized by predictable, rule-based speech errors (e.g., fronting, stopping, and final consonant deletion) that affect more than one sound. Children with phonological disorders are often highly unintelligible, or very difficult to understand, especially until their patterns and identified and understood.

What are some red flags or warning signs that my child may have a phonological disorder?

There are many different phonological processes. Some phonological processes are part of typically developing speech and others are atypical. Some of the most common phonological disorders include:

  • Weak syllable deletion: dropping a syllable that is unstressed (Eg. says “nana” for “banana” or “tato” for “potato”). Weak syllable deletion is anticipated to resolve by the age of 3.
  • Final consonant deletion: dropping final consonants in words (Eg. says “dah” for “dog”). Final consonant deletion is anticipated to resolve by the age of 3.
  • Fronting: replacing sounds in the back of the mouth such as “k, g, sh” with sounds in the front of the mouth such as “t, d, s” (Eg. says “tan” for “can,” “doh” for “go,” or “so” for “show”). Fronting is anticipated to resolve by the age of 4.
  • Cluster reduction: dropping one sound from a grouping of 2 or more consonants in words (Eg. “tin” for “twin,” “top” for “stop”). Accurate production of clusters without “s, r, l” such as “tw, nt, nd, mp, mb” are anticipated by the age of 4. Accurate production of clusters containing “s” are anticipated by the age of 5. Later-developing sounds “r, l” may be replaced with “w” (Eg. says “gwasses” for “glasses” or “pwincess” for “princess”) until 6-8 years.
  • Stopping: replacing long sounds such as “f, v, s, z, sh, th” or “ch,” “j” with short sounds such as “p, b, t, d, k, g,” (Eg. says “pan” for “fan” or “ton” for “son”). Stopping of “f, s” is anticipated to resolve by 3; “v, z” by 4, and “sh, th, ch, j” by 5.
  • Voicing errors: replacing a voiced sound for a voiceless sound, or vice versa (Eg. says “buy” for “pie” or “bat” for “bad”).
  • Gliding: replacing “r, l” for “w, y” (Eg. says “yif” for “leaf” or “wed” for “red”). Gliding is very common and can be a part of typical speech development until 6-8 years. 

When should I seek help?

  • If your child is exhibiting typically-developing phonological processes past the average age of resolution
  • If your child is exhibiting atypical phonological processes, such as backing, initial consonant deletion or vowel errors
  • If you child is very difficult to understand and/or showing frustration because others do not understand him/her

How is a phonological disorder evaluated?  

Evaluation often involves standardized testing to determine presence and severity of the disorder. During evaluation, the child is prompted to say words and/or sentences. Responses are transcribed in order to identify whether there are consistent patterns of error (phonological processes). Evaluation may also assess speech perception (child’s ability to distinguish between two similar sounds),  intelligibility (how often familiar and unfamiliar listeners understand the child) and stimulability (child’s ability to produce specific speech sounds given explicit teaching and models). 

If my child has a phonological disorder, what would potential treatment look like?

Treatment for phonological disorders varies depending on type and severity. In most cases, phonological processes which are anticipated to resolve the earliest (eg. final consonant deletion, fronting) are targeted first in therapy. Treatment for phonological disorders often uses similar methods to that of treatment for articulation disorders, as they frequently overlap. Additionally, therapy for phonological disorders often targets phonological awareness skills (Eg. hearing the difference between “bat” and “back,” rhyming, syllable segmentation). Treatment of phonological disorders can sometimes be a lengthy process. Progress towards resolution of phonological disorders can be supported and expedited through carryover of practice at home.


Selected Phonological Processes (

phonological_processes.pdf (