Phonological Disorder

Phonological disorders, often referred to as phonological process disorders, involve patterns of sound errors^[1]. Essentially, they are difficulties in the understanding and organisation of the sound system of a language. These disorders affect the individual's ability to use the rules and patterns that organise sound combinations in a particular language^[2].

Phonological processes are natural and typical in the speech development of young children^[3]. They use these processes to simplify speech as they're learning to talk. However, when these simplifications persist beyond the age when most typically developing children have stopped using them, it may be indicative of a phonological disorder.

Here are some common phonological processes:

1. Final Consonant Deletion: Omitting the final consonant in words. (e.g., "ca" for "cat")

2. Fronting: Sounds that should be said with the tongue placed towards the back of the mouth (like /k/ or /g/) are replaced with sounds at the front of the mouth (like /t/ or /d/). (e.g., "tup" for "cup")

3. Cluster Reduction: Reducing a consonant cluster to a single consonant. (e.g., "top" for "stop")

4. Stopping: Fricative or affricate sounds like /s/, /z/, /ʃ/, /ʧ/ are replaced with stops like /t/, /d/, /k/, /g/. (e.g., "doe" for "shoe")

5. Gliding: Replacing liquids /l/ and /r/ with glides /w/ and /j/. (e.g., "wun" for "run")

6. Weak Syllable Deletion: Omitting the unstressed syllable in a multisyllabic word. (e.g., "nana" for "banana")

There are some key differences between articulation disorders and phonological disorders.

• Phonological Disorder: The issue lies in understanding the rules and patterns of combining sounds in the target language. It's more about the mental organisation and representation of sounds.

• Articulation Disorder: The issue is related to the physical production of individual speech sounds. Children with articulation disorders may have difficulty producing specific sounds, leading to substitutions, distortions, omissions, or additions^[5].

Identification and treatment of phonological disorders often involve:

1. Assessment: A speech-language pathologist will evaluate the child's speech using standardised tests and spontaneous speech samples to identify error patterns.

2. Intervention: Treatment will focus on teaching the child the rules of the sound system in their language. Approaches like minimal pairs therapy (where two words that differ by one sound are contrasted) can be effective.

3. Generalisation: Therapy will aim to help the child apply what they learn to spontaneous conversation in various settings, ensuring they're not just using correct phonology in therapy but also in everyday life.

How are phonological disorders assessed? Assessing phonological disorders involves a combination of standardised tests, informal assessments, and detailed analyses of a child's speech^[5]. The assessment helps determine the nature and extent of the disorder and provides direction for appropriate intervention strategies.

Here's a breakdown of how phonological disorders are typically assessed:

Case History: Before any direct testing, it's essential to gather a comprehensive case history. This includes prenatal and birth history, developmental milestones, family history of speech and language disorders, and any previous therapies or interventions.

Hearing Screening: Before delving into phonological assessment, it's crucial to rule out any hearing issues. Even mild hearing loss or intermittent hearing issues, like those caused by chronic ear infections, can impact phonological development.

Standardised Tests: These are designed to compare an individual child's performance to norms established on a larger population. Some popular standardised tests for assessing phonological disorders include:

• Goldman-Fristoe Test of Articulation (GFTA)

• Hodson Assessment of Phonological Patterns (HAPP)

• Bankson-Bernthal Test of Phonology

• Khan-Lewis Phonological Analysis (KLPA)

• Note: The choice of test may vary based on the child's age, the suspected nature of the phonological issues, and the clinician's preference.

Spontaneous Speech Sample: Collecting a sample of the child's spontaneous speech in conversation provides invaluable information. It allows the speech-language pathologist (SLP) to note error patterns that occur in natural speech, which might not be evident in a more structured test environment.

Phonological Process Analysis: Once speech samples are collected, the SLP can analyse them for specific phonological processes (patterns of sound errors). For instance, the SLP might identify patterns like final consonant deletion, cluster reduction, or fronting.

Stimulability Testing: This involves assessing how well the child can imitate the correct form of misarticulated sounds when given a model or some instruction. If a child is stimulable for a sound, they may be more likely to correct that sound with intervention.

Intelligibility Assessment: Determining how understandable a child is to both familiar and unfamiliar listeners can help gauge the severity of the disorder. It can be assessed informally by observing the child's communication in different contexts or more formally by using rating scales.

Oral Peripheral Examination: Although primarily associated with articulation disorders, an examination of the oral structures (lips, tongue, hard and soft palate) and their functions ensures there are no physical abnormalities impacting speech production.

Dynamic Assessment: This involves teaching a new skill or concept and observing how the child responds to instruction. It helps in understanding the child's learning potential and the approaches that might work best in therapy.

Parent/Caregiver Interview: Talking with parents or caregivers provides insights into the child's speech and language development, their communication in different settings, and any concerns or observations the family might have.

Once the assessment is complete, the SLP will compile the results, possibly diagnosing a phonological disorder if the evidence supports it. They will then provide recommendations for therapy or further assessments, set goals, and plan interventions tailored to the child's unique needs.