Speech sound disorder affects a person’s ability to produce speech sounds clearly and consistently, which can make communication harder to understand in everyday conversations.
Written by: William Huynh, MPSA-CPSP, Senior Speech Pathologist
Published: 24 May 2026
Disclaimer: The information on this page is intended as general guidance only and should not replace professional medical advice, diagnosis, or treatment. If you have concerns about your child’s development or behaviour, speaking with a qualified healthcare professional is recommended.
A speech sound disorder is a communication difficulty that affects the way speech sounds are produced, organised, or understood. This can make words sound unclear, inconsistent, or different from what the speaker intends to say, which may affect everyday communication at home, school, work, or in social situations.
Speech sound disorders can affect both children and adults and may range from mild pronunciation difficulties to more noticeable speech differences.
Clinician’s Notes: Despite some overlap, speech sound disorders are different from language disorders. A speech sound disorder affects how speech sounds are produced and spoken, while a language disorder affects how a person understands, processes, or uses words and sentences to communicate meaning. As such, these are assessed differently in the clinic.
Speech sound disorders are commonly grouped into two main types: articulation disorders and phonological disorders. While both can affect speech clarity, clinicians look at them differently because they involve different underlying difficulties with speech production and sound patterns.
An articulation disorder affects the physical production of specific speech sounds. This means a person may know what sound they want to say, but has difficulty forming it correctly with the lips, tongue, teeth, or palate.
For example, someone with an articulation disorder may:
These errors are usually linked to individual sounds rather than broader speech patterns.
A phonological disorder affects the way speech sounds are organised and used within a language system. Rather than difficulty physically producing a sound, the person may use predictable sound patterns that simplify speech and make words harder to understand.
For example, someone with a phonological disorder may:
These patterns often affect multiple sounds at once and can make speech difficult for unfamiliar listeners to follow.
Speech sound disorders can have many possible causes, and sometimes there may not be a single clear explanation. Depending on the person and the type of speech difficulty involved, causes may include:
In some cases, a person may have no identifiable physical or neurological cause but still experience ongoing difficulty producing or organising speech sounds clearly. A speech language pathologist can assess speech patterns and help determine the type of support that may be appropriate.
Some speech sound errors are developmentally typical, especially in young children. For example, younger children may simplify difficult sounds or mispronounce longer words while speech skills are still developing.
However, certain patterns, persistence of errors, or impact on daily communication can suggest that further assessment may be helpful.
Treatment for a speech sound disorder depends on the type of speech difficulty, the person’s age, and how communication is being affected in daily life. A speech pathologist will usually begin with an assessment to identify which sounds or speech patterns are causing difficulty and whether the issue is related to articulation, phonological processing, motor speech, or another underlying factor.
Clinician’s Notes: Speech pathologists use a combination of standardised assessment tools and clinical observation to determine whether speech difficulties reflect a simple delay or an actual speech sound disorder. Common assessment tools may include the Diagnostic Evaluation of Articulation and Phonology (DEAP), Goldman-Fristoe Test of Articulation (GFTA), or the Clinical Evaluation of Language Fundamentals (CELF), alongside observation of speech clarity, sound patterns, and communication in everyday situations.
After assessment, speech therapy may involve:
For children, therapy is often play-based and adapted to their developmental stage. For teenagers and adults, treatment may focus more on functional communication goals at school, work, or in social settings.
Some mild speech sound difficulties improve naturally over time, while others benefit from structured intervention and regular practice. A speech therapist can help determine whether monitoring, short-term support, or ongoing therapy is likely to be most helpful.
William Huynh is a senior speech pathologist and the director of NDIS-registered provider Brighter Futures Allied Health. He has over a decade of experience working with children and adults with complex communication needs, including disability, dysphagia, and acquired language impairments. William has completed specialist training in approaches such as Key Word Sign, LAMP Words for Life, Grid 3, and Hanen’s More Than Words. He also supervises speech pathologists and student placements, supporting evidence-based and family-centred practice.
