Speech Sound Development

As young children learn to speak, they may struggle to pronounce certain sounds correctly. This is a part of typical development. After all, speech skills naturally develop over time, and errors are often part of the learning process. As children grow older, some sounds come easy, like /p/, /m/, and /w/. Others are more difficult, such as /z/, /sh/, and /th/. By age 5, most children should be able to pronounce almost all types of speech sounds.

However, when a child has a hard time saying sounds or words correctly past a certain age, this can be a sign of a speech sound disorder. As a parent, it can be stressful to watch your child struggle to clearly communicate their thoughts and ideas and be understood when they speak.

Some adults have speech problems that started as a child and were never properly treated, so they've persisted over time. 

What is a speech sound disorder?

Producing speech sounds correctly requires both the knowledge of a desired speech sound, as well as the ability to coordinate the jaw, tongue, and lips with breathing and vocalizing. Children who can't pronounce certain sounds or words by an expected age may have a speech sound disorder. It's often difficult to understand someone with a speech sound disorder and, in many cases, it can affect a person’s social, academic, and overall development.

There are two types of speech sound disorders: functional and organic. This is why assessment and diagnosis by a certified speech-language pathologist, also known as a speech therapist, is so important. Speech delays can be effectively treated, and research has shown that earlier interventions lead to better outcomes.

Functional speech sound disorders

For these disorders, the cause is unknown:

• Articulation disorders: The production of sounds involves the coordinated movements of the lips, tongue, teeth, palate (top of the mouth), and respiratory system (lungs). Children with articulation disorders have difficulty using these motor functions to physically produce the correct speech sounds. The result is the inability to form legible words past a certain age. Sounds may be distorted or swapped altogether.
• 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 produce the /d/ sound, but they may swap it out for the /g/ sound in certain words, saying “doe" instead of "go."

Organic speech sound disorders

For these disorders, the cause is known:

• 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 the oral and facial structures can impact speech sound production, as is the case for cleft lip and palate. 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. Speech problems vary depending on the severity of the hearing loss.

What is the difference between articulation and phonological disorders?

An articulation disorder is a difficulty at a phonetic/motoric level. People with this disorder have trouble making individual speech sounds.A phonological disorder is a difficulty at the phonemic level, in the brain. The person can say sounds correctly, but they struggle to correctly form the sounds into words. Compared to articulation disorders, it is often Many children with phonological disorders often exhibit patterns of speech errors making it more difficult to understand someone with a phonological disorder than someone with an articulation disorder. Additionally, children who have phonological disorders usually also struggle phonemic awareness (the understanding of sounds and sound rules in words) creating struggles with language and literacy, which can affect their academic success. Distinguishing between articulation and phonological disorders isn't always easy. However, a proper diagnosis is extremely important, as it will largely determine a person’s treatment plan. Therefore, if you suspect your child has a speech sound disorder, it’s imperative that you receive an evaluation from a certified Speech Language Pathologist. 

How common are speech sound disorders?

The prevalence of speech sound disorders (both articulation and phonological disorders) in young children is approximately 8% to 9%. Approximately 5% of children have noticeable speech problems by the time they reach first grade. 

According to a 2012 survey from the National Center for Health Statistics, speech problems were the most common type of communication disorder in children:

• 42% of children 3 to 10 years of age had speech sound problems
• 24% of children 11 to 17 years of age had speech sound problems

Poor speech sound development in children have been associated with lower literacy outcomes. Studies have also shown that children with speech sound difficulties in their preschool years were more likely to have trouble reading as they got older.

What are the signs and symptoms of a speech sound disorder?

It's completely normal for children to pronounce sounds incorrectly as they’re growing up. They may substitute one sound for another, for example, swapping the /w/ sound for an /r/ sound and saying “white” instead of “right.” Or they omit certain sounds altogether, pronouncing “nana” instead of “banana.” While these mispronunciations can easily be overlooked as cute in young children, they can potentially lead to developmental implications if they continue. While all children develop at different speeds, there are certain speech sound benchmarks they should be able to reach by certain ages. 

According to the American Speech-Language-Hearing Association (ASHA), these are the ages when most English-speaking children should develop certain sounds.

By 3 months:

• Makes cooing sounds

By 5 months:

• Laughs and makes playful sounds

By 6 months:

• Makes speech-like babbling sounds like puh, ba, mi, da

By 1 year:

• Makes longer strings of sounds like mimi, upup, bababa

By 3 years:

• Says /m,/ /n/, /h/, /w/, /p/, /b/, /t/, /d/, /k/, /g/, and /f/ in words
• People familiar with the child can understand their words

By 4 years:

• Says /y/ and /v/ in words
• May still make mistakes on /s/, /sh/, /ch/, /j/, /ng/, /th/, /z/, /l/, and /r/ sounds
• Most people understand the child’’s speech

According to Stanford Children’s Health, there are some common signs and symptoms your child may have with an articulation or phonological disorder.

Symptoms of articulation disorders: 

• Errors due to differences in the orofacial structures (saying “hip” instead of “ship”)
• Distorting sounds in words (saying "thith" instead of "this")
• Swapping sounds in words (saying "wadio" instead of "radio")

Symptoms of phonological disorders: 

• Syllable reduction (saying "bay" instead of "baby")
• Simplifying a word by repeating two syllables (saying "baba" instead of "bottle")
• Leaving out a consonant sound in the beginning or end of a word (saying "at" or "ba" instead of "bat")
• Using only front or back consonant sounds (saying "tat" instead of "cat") or (saying “dod” instead of “dog”)
• Note: Having an accent is not a speech sound disorder. While the mispronunciation of certain sounds and words can sound like a speech problem, it may simply be the result of an accent in which Accent Reduction Therapy can be extremely helpful. 

What causes a speech sound disorder?

Most of the time, a speech sound disorder has no known cause. However there are some possible factors that may cause or contribute to a speech sound disorder:

• Brain damage, such as a head injury
• Intellectual or developmental disability, such as autism
• A genetic disorder, such as Down syndrome
• Problems with hearing or hearing loss, such as a history of ear infections
• Physical abnormalities that affect speech, including cleft palate or cleft lip
• Disorders affecting the nerves involved in speech

What are the risk factors for speech sound disorders?

As mentioned, often the cause of a speech sound disorder is not known. However, there are certain risk factors that can make a child more prone to speech sound disorders. According to Stanford Children’s Health, these can include: 

• Developmental disorders such as autism
• Genetic disorders such as Down syndrome
• Hearing loss
• Nervous system disorders such as cerebral palsy
• Illnesses such as frequent ear infections
• Physical problems such as a cleft lip or palate
• Too much thumb-sucking or pacifier use
• Low education level of the parent or caregiver
• Lack of support for learning in the home

According to ASHA, research has shown that the following risk factors may also increase a child’s likelihood of developing a speech sound disorder: 

• Gender: The incidence of speech sound disorders is higher in males than in females.
• Pre- and perinatal problems: Factors such as maternal stress or infections during pregnancy, complications during birth, preterm delivery, and low birthweight were found to be associated with delay in speech sound acquisition and with speech sound disorders.
• Family history: Children who have family members such as parents or siblings with speech and/or language difficulties may be more likely to have a speech disorder.

How are speech sound disorders diagnosed?

As with any condition, you should contact your pediatrician if you suspect signs of a speech sound disorder. Most likely they will start by checking your child’s hearing. Many children with hearing loss are unable to properly listen to the words and sounds they make. If hearing loss is ruled out, you will likely be referred to a certified speech therapist for a Speech evaluation. Speech Language Pathologists (SLPs) are specialists in all areas of communication and are the most qualified professionals to evaluate, diagnose, and treat speech sound disorders. The earlier the intervention starts, the quicker the issue can be addressed and corrected. Your speech therapist will watch and listen to your child. They can help determine if your child's speech issues are a normal part of development and will gradually go away, or if they're the result of a speech sound disorder. To do this, the speech therapist will evaluate a variety of factors, including your child's speech and language skills, medical history, and how they move their lips, jaw, and tongue.

How are speech sound disorders treated?

With early speech therapy intervention, many children with articulation and phonological disorders see significant improvement in their ability to properly produce speech sounds.

Speech therapists work with you and your child to develop an individualized treatment plan to help overcome speech challenges. Some children have difficulty with a certain group of sounds that share similar characteristics. For example, your speech therapist may focus on improving speech sounds that are produced in the back of the mouth (like /k/ or /g/), or sounds that require air flow to be produced (like /f/ or /s/). This practice is called a phonological therapy approach.

The first and most important step is evaluation and identification of speech sound errors.

If you suspect a Speech Sound Disorder, schedule an assessment today.