Speech sound disorders (SSD) may refer to any and all difficulties associated with the perception, production, and/or phonological articulation of speech sounds. For example, a child older than 4-years who says "scoo" instead of "school" or "thith" instead of "this" may have a speech sound disorder.
Primarily, speech sound disorders (SSDs) have been subdivided into two broad categories –
1. Organic Speech Sound Disorders
These are SSDs resulting from neurological or motor disorders. Organic speech sound disorders include dysarthria and childhood apraxia of speech. SSDs resulting from structural anomalies like cleft palate and sensory disorders like hearing impairments also fall under organic speech sound disorders.
2. Functional Speech Sound Disorders
SSDs that are related to motor production of speech sounds and the linguistic aspect of speech production fall under the category of functional speech sound disorders. Functional speech sound disorders can be further subdivided into two categories.
Articulation Or Phonetic Disorders
Articulation disorders focus on the errors in the production of individual speech sounds. These include substitutions or distortions.
Phonemic Or Phonological Disorders
These disorders focus on rule-based errors, which may affect more than one sound during speech. For example, deletion of the final consonant, stopping and fronting.
Speech sound disorders can be articulatory, phonological, or organic. To determine whether your child is simply a late talker, or if they have a speech sound disorder, you need to consult a speech-language pathologist (SLP).
Speech Sound Disorders In Children – The Risk Factors
A child younger than 4-years may substitute one sound for another. It is common for young children to replace "r"s with "w"s or leave out parts of words. So, if a child younger than 36-months says "wabbit" instead of "rabbit" or "nana" instead of "banana" it's fine!
A 3-year old should say m, n, w, p, b. d, k, t, h, f, and g in their speech. Children take more time to produce z, w, and th sounds correctly. Familiar people should understand their speech, and unknown people should understand around 75% of their speech.
A child who is 4-years old should be able to say v and y in words quite clearly but may make mistakes on s, sh, ch, ng, th, j, z, l, and r sounds. All listeners should be able to understand the child's speech.
However, if a child older than 4-year still uses substitutions and shortened versions of familiar words, they may be at a higher risk of speech sound disorders.
Frequent errors in articulation of phonemes may signal a speech sound disorder like mild dysarthria or childhood apraxia of speech. Other disorders that may contribute to frequent misarticulations and phonological errors are autism spectrum disorder (ASD), Down syndrome, Cerebral Palsy (CP), hearing loss, and traumatic brain injury (TBI).
Let Us Go Through the Most Common Organic Speech Sound Disorders in Children -
What Is Dysarthria?
Dysarthria is a not-so-common motor speech disorder. Those with dysarthria find it difficult to talk without slurred or mumbled speech. It may happen due to weakened muscles resulting from brain damage.
The causes of dysarthria include stroke, injury to the brain, brain tumors, Parkinson's diseases, ALS, MS, cerebral palsy (CP), or Muscular Dystrophy.
Dysarthria can co-occur with other speech and language disorders/problems like stuttering.
Damage to the nerves or brain is the primary cause of muscle weakness leading to slurred or unintelligible speech. Therefore, dysarthria can affect individuals of all ages and genders.
Only a licensed SLP can diagnose dysarthria. Since there is no medical examination that can determine if an individual has dysarthria, the SLP will rely on astute observation, repeated assessment of speech and language to come to a conclusion about the diagnosis.
The SLP will observe the movements of the tongue, jaw, lips, and breathing to determine the severity of the disorder. They will listen to single words, complete sentences, phrases, and conversations before giving a diagnosis.
The treatment for dysarthria will depend on the cause and severity. However, speech therapy for dysarthria may include –
- Slowing one’s speech
- Using one’s breath to speak louder
- Exercising to make the affected muscles stronger
- Moving one’s lips and tongue to gain more control
- Saying target words and sounds in sentences
- Learning augmentative and alternative methods of communication (AAC)
What Is Childhood Apraxia Of Speech (CAS)?
Childhood apraxia of speech is when a child knows what to say but cannot say it due to the loss of function or control of the nerves that control the articulators. It happens when the child's brain has difficulty coordinating the movements of the lips, tongue, jaws, and other oral parts necessary to produce the correct sounds at the right time.
Some may refer to childhood apraxia of speech (CAS) as developmental apraxia or verbal dyspraxia. Despite the use of the term "developmental," it does not go away on its own like some cases of developmental stuttering. Childhood apraxia of speech demands intense speech therapy and treatment under the guidance of a licensed SLP.
Children with CAS have varying signs and symptoms. Some of the most common ones are –
- Making frequent and inconsistent errors while saying the same word in different sentences or contexts
- Putting stress on the wrong word or syllable
- Distortion or changing sounds while speaking
- Saying shorter words more correctly as compared to longer words
- Children with CAS may have problems that are unrelated to speech. Such as –
- Trouble with fine motor skills
- Delayed development of speech and language
- Problems reading, writing, and spelling
The causes of CAS remain unknown. In rare cases, damage to the areas of the brain that control the movement of oral muscles may cause CAS. This damage may be due to a genetic disorder, brain tumor, stroke, or traumatic brain injury (TBI).
The treatment for childhood apraxia of speech can be lengthy, and the improvement may be slow. The prognosis depends upon the severity of the signs and symptoms of childhood apraxia of speech.
An SLP will help your child with the following –
- Planning the movements necessary to say the sounds correctly
- Making the movements correctly each time
However, oral exercises that aim to strengthen oral muscles rarely help in the case of CAS. The inability to produce the correct sounds does not stem from the weakness of oral muscles but from the lack of the ability to control them.
An SLP may also help your child learn augmentative and alternative means of communication like gestures, sign language, electronic devices, or the use of picture boards to communicate.
What Are Structural Speech Disorders In Children?
Structural speech disorders are more common among children. When a child is unable to produce the correct sound due to structural deficits or anomalies in and around the mouth region.
One of the most common structural abnormalities that contributes to speech sound disorders (SSDs) is a cleft palate or lip. Experts believe that a cleft lip may be caused by a combination of genetics and environmental factors. It happens when the tissues of the baby’s face and mouth do not form and fuse completely.
However, a child with a cleft palate may face a higher risk of ear infections and hearing loss. Hearing loss is a sensory/perceptual disorder that causes speech sound disorder in the near future!
The diagnosis of structural organic speech sound disorder may be simpler than diagnosing apraxia or dysarthria among children.
In most cases, if the cleft lip or palate can be corrected with surgery, the child’s speech improves drastically. However, the child may need to practice learning the correct movement of the newly reconstructed lip(s) and palate with an SLP to speak clearly and confidently.
What Are Sensory or Perceptual Speech Sound Disorders?
If a child has complete hearing loss, they are unable to hear the sounds others make while speaking and the ones they make as well. The speech deficits will vary depending upon the extent of hearing loss.
A child who experiences repeated ear infections is also at a high risk of losing their hearing. Do not ignore minor and recurrent ear infections in children. Talk to a pediatrician and/or ENT immediately!
- Around 50% of the cases of hearing loss in children is due to genetic factors.
- 25% of the cases are due to infections the mother incurs during pregnancy, head trauma, post-natal complications and post-natal infections.
- Sadly, the cause of hearing loss in 25% cases is still unknown although not idiopathic!
Some hearing losses may be reversible completely or partially through surgery. In some cases, hearing may be restored through electronic (hearing) aides, cochlear implants and other devices.
Some signs of hearing loss in babies may include –
- Lack of a response or alarm at loud noises
- Doesn’t turn to a voice or source of sound after 6-months of age
- Does not say “mama,” “dada,” or other single words after 12-months of age
- Does not respond to their own name after they are 12-months old
If you believe that your child is experiencing a speech delay or exhibiting signs of speech sound disorders, you should first consult their pediatrician or ENT (Ear-nose-throat doctor). Thorough testing of their hearing skills can determine whether their speech delay or SSD is due to the loss of hearing.
Studies show that children who experience speech problems due to hearing loss fare better with assistive hearing aids and implants in the long run. However, your child will need the help and guidance of an SLP to catch up with their peers if they are already behind several speech and language milestones.
Stuttering or Stammering
Stuttering is not a speech sound disorder. It is a fluency disorder which is also known as developmental stuttering or childhood-onset fluency disorder.
In some cases, children outgrow stuttering without any speech therapy. Core behaviors of stuttering include repetitions, blocks and prolongations.
Other signs may include adding sound(s) before a feared word, repeating words, part or whole sentences, trailing off and substitution of words.
Stuttering therapy can include exercises and CBT (cognitive behavioral therapy) that address the core and secondary behaviors of stuttering. Stuttering treatment may take weeks or even months. Your child’s increase in speech fluency will depend upon multiple factors including the severity of their stuttering.
Stuttering can coexist with speech sound disorders like dysarthria, childhood apraxia of speech, and hearing impairments. The coincidence of stuttering with SSDs makes it incredibly difficult to diagnose and treat.
A trained and experienced SLP can double-diagnose a child after significant observation and testing.
How to Treat Speech Sound Disorders that Co-occur with Stuttering?
While each SLP has their own module for the treatment of stuttering and speech sound disorders (SSDs), the approach depends upon the effects or impacts of these disorders on the child.
Depending upon the factors that affect the child most, the SLP can choose either one of the following treatment methods -
1. Sequential Treatment
The treatment begins by treating stuttering or speech sound disorder first. The idea is to treat one disorder at a time until improvement is visible and persistent.
2. Cyclical Treatment
The SLP sets up a cyclical speech therapy schedule that addresses stuttering and speech sound disorders back-to-back. They may begin with stuttering treatment, switch to speech sound disorder therapy and then back to stuttering therapy without break.
3. Simultaneous Treatment
It is the most common form of speech therapy for children with double diagnosis. The speech therapist uses tools and resources that can treat stuttering and articulation or phonological disorders at the same time.
The co-occurrence of a speech sound disorder and fluency disorder can be incredibly challenging to a child as well as their caregivers. It is important to remain patient and attend all therapy sessions to see significant improvement.