What Is a Speech Sound Disorder or Phonological Disorder?
2 min read
One of the most common reasons children are referred to speech therapy is because their speech is difficult to understand. Parents often hear terms like speech sound disorder, articulation disorder, or phonological disorder, but these terms do not all mean the same thing. Understanding the difference can help families better understand their child’s evaluation and treatment.
A speech sound disorder (SSD) is a broad term used to describe difficulty producing speech sounds correctly. It includes both articulation disorders and phonological disorders. While both affect speech clarity, the underlying cause is different.
What Is an Articulation Disorder? #
An articulation disorder occurs when a child has difficulty producing one or more speech sounds correctly. The child knows which sound they want to say but has trouble placing the tongue, lips, jaw, or teeth in the correct position to produce it accurately.
For example, a child may substitute one sound for another, distort a sound, or leave a sound out completely. A child may say “wabbit” instead of “rabbit” or produce a lisp when saying the /s/ sound.
Articulation errors may involve using the wrong place in the mouth to produce a sound, using the wrong manner of airflow, or producing a voiced sound instead of a voiceless sound, or vice versa. These errors usually affect specific speech sounds rather than an entire pattern of speech.
Speech-language pathologists evaluate exactly how a child produces each sound to determine whether an articulation disorder is present.
What Is a Phonological Disorder? #
A phonological disorder is different. Instead of having difficulty making individual sounds, the child has difficulty learning the rules or patterns for how speech sounds are organized in words.
Children with phonological disorders often use predictable error patterns called phonological processes. These patterns simplify speech but continue beyond the age when most children have naturally outgrown them.
For example, a child may consistently substitute one group of sounds for another. Rather than making an occasional mistake, they use the same pattern over and over again.
One example is backing, where sounds normally produced at the front of the mouth, such as /t/ or /d/, are replaced with sounds made farther back in the mouth, such as /k/ or /g/. A child might say “key” instead of “tea.”
Other common phonological processes include:
- Fronting – replacing back sounds like /k/ and /g/ with front sounds like /t/ and /d/.
- Final consonant deletion – leaving off the last sound in words, saying “ca” for “cat.”
- Cluster reduction – simplifying consonant blends, saying “pane” instead of “plane.”
- Stopping – replacing continuous sounds like /f/ or /s/ with stop sounds such as /p/ or /t/.
- Gliding – replacing /r/ or /l/ with /w/, such as “wabbit” for “rabbit.”
Many of these processes are part of normal speech development in young children. However, if they continue beyond the expected age, speech may become difficult to understand and intervention may be recommended.
How Are These Disorders Diagnosed? #
A speech-language pathologist performs a comprehensive speech evaluation to determine whether the child has an articulation disorder, a phonological disorder, or a combination of both. The evaluation examines which sounds are affected, how consistently errors occur, whether patterns are present, and how easily others can understand the child’s speech.
Because treatment is different for each type of disorder, an accurate diagnosis is important.
Can Speech Improve? #
Yes. Most children with speech sound disorders make excellent progress with speech therapy. Treatment is individualized based on the child’s needs.
Children with articulation disorders learn how to correctly position the mouth to produce specific sounds. Children with phonological disorders learn the sound patterns of the English language and practice using those patterns correctly in words, sentences, and conversation.
Early intervention often leads to faster progress and helps children become more confident communicators.
There Is Hope #
Speech should become easier to understand as children grow. If your child is difficult to understand or continues making speech errors beyond the expected age, a speech-language evaluation can identify the reason and guide treatment.
At Bridge Disability Network, we help families connect with speech-language evaluations, therapy services, resources, and financial assistance so children with speech sound disorders can develop clear, confident communication and reach their full potential.