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Phonological Delays and Disorders



Phonological disorder is a type of speech sound disorder. There is no known cause. Children with phonological disorder may have a family history of the same, but this is not always the case.


Children with a phonological speech disorder have phonological systems that are not developing as expected. This system is how our brains represents how speech sounds influence meaning. For example, we know that in the words ‘cat’ and ‘pat’ they differ by one phoneme (/k/ and /p/) and that this changes the word’s meaning.


Children with phonological disorders typically make predictable, rule-based speech errors. For example, they may exhibit ‘velar fronting’ in which they substitute /k/ and /g/ with /t/ and /d/ (‘cup’ to “tup”, ‘go’ to “doh”). Most often, these errors are those younger children make (‘phonological processes’), but the child did not suppress them at the age children typically do. For example, velar fronting is typically suppressed by age 3½, so a child who is fronting at age 5 is considered to have a phonological delay. Phonological errors usually involve substitutions (e.g., (‘cup’ to “tup”) or omissions (e.g., ‘star’ to “tar”).



Children with phonological disorder may range from mild to severe. Judgments of severity are based on the number of error processes the child exhibits, their overall speech intelligibility, and how typical or atypical their errors are. The more severe a child’s speech disorder, the longer treatment will take.


Severe Phonological Disorder


Children with more severe phonological disorders may exhibit ‘atypical phonological processes’ – error patterns that are not produced in typically developing children. For example, although ‘fronting’ is a typical process, ‘backing’ is not. ‘Backing’ is when a child substitutes /t/ and /d/ with /k/, /g/, or even /h/ (e.g., ‘two’ to “coo”). Young children with a severe phonological disorder may also frequently delete the first and/or last consonant sound in words, making it sound like they “talk in vowels” (e.g., ‘up’ to “uh”, ‘dada’ to “ah-ah”, ‘apple’ to “ah-oh”).


Inconsistent Phonological Disorder


For most children with phonological disorders, their errors are consistent and predictable. For example, for a child with a mild phonological delay who fronts, when they make an error on /k/, it will likely always be a /t/ substitution (before they start treatment). Some children, however, have inconsistent phonological disorder. These children make ‘inconsistent errors’ on the same word when they try to repeat it more than once. For example, when trying to say ‘spider’, on their first attempt they may say “fider”, then “sider”, then “pider”. Inconsistent phonological disorder is another more severe form of phonological disorder.




There are many effective treatment approaches available for children with phonological disorder, and these children do indeed develop intelligible speech with appropriate and regular treatment with a speech-language pathologist.


Your child’s speech-language pathologist will discuss treatment options with you and make recommendations about how frequently your child should participate in treatment, whether it should be one-on-one or in a small group, and whether it should be provided directly with a speech-language pathologist (or an assistant) or done primarily through home programming. Such recommendations will be based on your child’s profile (e.g., age, severity, other communication disorders, ability to participate in treatment) and access to services in the public sector and/or private sector (e.g., SLP’s caseload, family’s schedule, family’s financial resources).


Generally speaking, the more severe the phonological disorder, the longer your child will require treatment. Children with very severe phonological disorders may require support for many years starting in preschool and into their school-years.


Augmentative Communication


For children with severe speech sound disorders, an augmentative communication system may be recommended. An augmentative system is meant to supplement or augment your child’s verbal output. For example, they may have an iPad application with a display of pictures and when they select a picture or series of pictures to make a sentence, the device says the message aloud for them.


Augmentative systems do not inhibit the development of speech and expressive language. In fact, they promote this development. Furthermore, use of an augmentative system will enable a child to express their thoughts and needs while they work on their speech, thus reducing frustration and barriers to socializing.


Reading Acquisition


Since reading and writing are an extension of our speech and language skills, children with phonological disorders are at a higher risk of later having phonologically-based difficulties with reading acquisition. Not all children with phonological disorders will have trouble learning to read, and not all children with reading difficulties have had a speech sound disorder, but the risk is greater.


Your child’s speech-language pathologist will give you advice on how to promote pre-literacy skills such as print awareness, letter knowledge, and phonological awareness. Promoting the development of these skills early on will reduce your child’s risk of reading difficulties later. It will also make you more aware of the possibility so that if your child does later have trouble learning to read, you can get them appropriate support as early as possible.

reading acq
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