Causes, Signs and Symptoms, Diagnosis, Treatment and Prognosis of Phonological Disorder
Before I explain phonological disorders, we need to clear up the confusion between phonological disorders and articulation disorders. Both of these conditions are speech disorders that result in speech sound errors. However, an articulation disorder occurs at the phonetic level (the individual speech sounds that are specific to a language), while a phonological disorder is based on errors at the cognitive or linguistic level (the pattern of sounds in a language).
A child with an articulation disorder knows where each sound is supposed to be placed in a word, but he or she has trouble making the sounds correctly with the articulators (lips, tongue, teeth, jaw, and velum). On the other hand, a child with a phonological disorder can produce the sounds correctly, but the sounds are used in the wrong places in words (fire becomes pire) or omitted completely (book becomes boo-). Both disorders adversely affect speech intelligibility (how well the listener understands the child), and a child can have both disorders at the same time.
There are a variety of patterns of errors, called phonological processes, such as fronting, backing, stopping, and gliding (see below for more details). Some of these processes are normal at young ages but should be outgrown by a certain age, while other processes are only heard in the speech of a child with a phonological disorder.
It is important to note that young children who are learning to talk make many speech mistakes. This is not necessarily a cause for concern. You should have your child evaluated by a speech-language pathologist (SLP) only if your child does not produce any sounds or seems to make more errors than his or her same-aged peers. If you are concerned, talk to your pediatrician or consult an SLP.
As with most developmental speech-language disorders, the cause of phonological disorders is mostly unknown. Phonological speech errors are often present in children who have other developmental, neurological, or genetic disorders.
Hearing loss or kids who have had many ear infections at a young age may also be at a higher risk for a phonological disorder.
There is some research that suggests children from families who have a history of speech and language disorders may be at higher risk for a phonological disorder.
The speech-language pathologist (SLP) will listen to your child’s speech to identify patters of errors, called phonological processes, which allow the child to simplify the adult speech. Some of these errors occur in normal development, while other errors are not typically heard in early speech.
Common Phonological Processes: These patterns are heard in the speech of many young children, but most children eliminate (or outgrow) the processes by a certain age. A few processes are listed below:
Final-consonant deletion (FCD) – a consonant at the end of a syllable or word is deleted. /hou/ instead of house. Usually eliminated by age 3 to 3½ years.
Fronting –a velar sound, or a sound made at the back of the mouth, like /k/ or /g/, is spoken as a front sound, or a sound made at the front of the mouth, like /t/ or /d/. Instead of key, the child might say tee. Usually eliminated by age 3 to 3½ years.
Stopping – an airy sound, like the fricatives /f/ and /s/ and the affricate /sh/, is replaced with a stop sound, like /t/ or /d/. The word see becomes tee. Usually eliminated by age 3 to 4½ years.
Gliding – the liquid consonants /l/ and /r/ are replaced with the glide consonants /w/ or /y/ (the “yuh” sound is actually written as /j/ in the phonetic alphabet). Yellow becomes yewow, or rabbit becomes wabbit. Usually eliminated by age 5 years.
Atypical Phonological Processes: These error patterns are not typically heard in normal speech development. A child who makes these errors is more likely to have a phonological disorder versus a developmental delay. A couple of these errors are listed below:
Initial-consonant deletion – the beginning consonant of a word is deleted. Bee might become ee.
Backing – a front sound, such as /t/ or /d/, is spoken as a velar, or back, sound, like /k/ or /g/. Tea might become kea.
Through a comprehensive articulation-phonological evaluation, the SLP will identify any phonological processes used in the child’s speech. The SLP will determine whether or not the processes are developmentally appropriate before assigning the phonological disorder diagnosis.
These are the tests we use at Kidmunicate
Goldman Fristoe Test of Articulation (GFTA)
Phonological Process Analysis, such as the Kahn-Lewis Phonological Analysis (KLPA), which analyzes speech errors by identifying the sound simplification rules or patterns in the child’s speech.
Once a diagnosis has been made, it is very important that the child receive speech therapy services. The SLP will target each pattern of sounds systematically. Speech therapy will target groups of sounds using auditory discrimination tasks, minimal pairs approach, and some traditional articulation therapy methods (e.g., cues for proper placement of articulators).
Since children with phonological disorders often have many sound system errors, the best approach is to work on types of sounds (front sounds, back sounds, fricatives) rather than individual sounds (/p/, /t/, /k/). The Cycles Approach to Phonological Remediation introduced by Barbara Williams Hodson and Elaine Pagel Paden seems to be the most effective approach for phonological disorders.
All situations are different, so we cannot provide a specific prognosis for improvement. In general, like articulation disorders, the prognosis of phonological disorders depends on the cause and severity of the disorder. In many cases, phonological errors can be eliminated completely with treatment and practice. We can tell you that chances for success improve with early intervention and home practice.