Understanding the Different Types of Speech Sound Disorders
Leanne Sherred, M.S., CCC-SLP
It's normal for toddlers and young children to have a hard time pronouncing certain sounds. After all, speech skills naturally develop over time, and errors are often a part of the learning process.
Some sounds may come more easily, like /p/, /m/, and /b/. Others are more difficult, such as /r/, /z/, and /s/. By the age of 5, most children should be able to pronounce almost all types of speech sounds. When a child has difficulty saying sounds or words correctly past a certain age, this can be a sign of a speech sound disorder.
Adults can struggle with speech sound disorders, too. Some adults have had problems since childhood that were never properly treated. Other disorders may have developed as a result of a stroke or traumatic brain injury.
It's often difficult to understand someone with a speech sound disorder. It can be stressful to watch your child struggle to communicate their needs and ideas--and frustrating as an adult to deal with speech challenges. The good news is that speech therapy can make a big difference, both for children and for adults.
Two types of speech sound disorders
Broadly speaking, there are two types of speech sound disorders: functional and organic. Functional speech sound disorders can further be broken down into articulation disorders and phonological disorders. Let's take a look at each of these and discuss what they sound like and when to seek help.
Articulation disorders
Producing a sound involves coordinated movements of the lips, tongue, teeth, palate (top of the mouth), and respiratory system (lungs). Children with articulation disorders have a tough time using these motor functions to physically produce the correct speech sounds. The result is the inability to form clear words past a certain age. Sounds may be distorted or swapped for another sound.
Phonological disorders
Phonological disorders are characterized by a regular pattern in which a person may be able to produce individual sounds correctly, but they have difficulty putting these sounds together to form words. For example, they may be able to make the /d/ sound, but they swap it out for the /g/ sound in certain words, pronouncing “doe" instead of "go."
The difference between articulation and phonological disorders
An articulation disorder is a difficulty at a phonetic level, using motor skills. Kids with this disorder have trouble making individual speech sounds.
A phonological disorder is a difficulty at the phonemic level, in a person's brain. They can say sounds correctly but struggle to form them into words.
Compared to articulation disorders, it's often more difficult to understand someone with a phonological disorder. Many children with phonological disorders and phonemic awareness disorders (problems with understanding sounds and sound rules in words) also have trouble with language and literacy, which can affect their experience in the classroom.
Telling the difference between articulation and phonological disorders isn't always easy. However, a proper diagnosis is extremely important, since it will determine a person’s speech therapy treatment plan. If you suspect your child has a speech sound disorder, it’s important to receive an evaluation from a certified speech-language pathologist, also known as a speech therapist.
Organic speech sound disorders
Often, the cause of a speech sound disorder isn't known. The exception is organic speech sound disorders, which do tend to have a known cause. These fall into several categories:
Motor/neurological: Motor speech disorders occur when muscle coordination or strength is impacted. Motor speech disorders can be developmental or acquired after neurological damage, such as a stroke or traumatic brain injury.
Structural: Differences in oral and facial structures can impact speech sound production, such as for children with cleft lip and palate. These structural differences can also be caused by trauma or surgery.
Sensory/perceptual: Hearing impairment can cause speech sound difficulties, as children aren’t able to hear sounds the way others produce them. Depending on the severity of the hearing loss, the impact on speech may vary.
What to do if your child is struggling with speech sounds
Learning about speech problems is one of the most important things a caregiver can do to help their child. But as mentioned above, identifying the difference between speech sound disorders can be difficult for an untrained eye. This is why assessment and diagnosis by a certified speech-language pathologist is so important. If your child is having a tough time pronouncing certain sounds, contact a speech therapist for an evaluation. Speech sound disorders can be treated, and research has shown that the earlier speech therapy begins, the better the outcomes.
