Speech Sound Disorder Fast Facts

Speech sound disorder (SSD) is a communication disorder in which a person has trouble correctly pronouncing word or letter sounds.

Difficulty pronouncing certain sounds is normal for children, but in speech sound disorder, the difficulty continues past the age when pronunciation problems are typical.

Many children learn to overcome SSD problems with treatment, but without treatment, the disorder can continue into adulthood.

SSD can be caused by various neurological, physical, or developmental factors. However, in many cases, the cause of the disorder is unknown.

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Many children learn to overcome SSD problems with treatment, but without treatment, the disorder can continue into adulthood.

What is Speech Sound Disorder?

Speech sound disorder (SSD) is a disorder of speech that causes problems with the pronunciation of certain words or sounds. It is typically a childhood disorder, but it may continue into adulthood. In some cases, SSD may emerge later in life as a result of a brain injury or stroke.

Unusual pronunciations consistent with an accent or dialect are not symptoms of this disorder.

Types and Symptoms of SSD

It is normal for children to have difficulty pronouncing certain sounds or words as their speech develops. However, children with SSD continue to have trouble with pronunciation past the age when speech difficulties are typical. In general, children can usually produce all of the sounds typically used in speech by age 4-8, but children with SSD have pronunciation difficulties beyond this age range.

Speech sound disorders are categorized into subtypes depending on their symptoms. The two main subtypes are articulation disorders and phonological process disorders.

Articulation Disorders

These disorders involve incorrect pronunciation of certain sounds or words.

Symptoms of articulation disorders may include:

  • Leaving off sounds within words
  • Adding extra sounds to words
  • Distorting sounds (e.g., saying “th” instead of “s”)
  • Switching sounds of letters (e.g., replacing “r” sound with “w”)

Phonological Process Disorders

These disorders involve a consistent pattern of mispronouncing words.

Symptoms of phonological process disorders may include:

  • Reducing a multi-syllable word to a single syllable
  • Mispronouncing words by repeating syllables (e.g., saying “baba” instead of “bottle”)
  • Dropping consonant sounds in words (e.g., saying “tar” instead of “star”)
  • Changing specific consonant sounds in words (e.g., saying “tat” instead of “cat”)

What Causes Speech Sound Disorder?

The cause of speech sound disorders is often unclear, but sometimes a neurological, physical, or developmental disorder is an identifiable cause. Possible causes include:

In addition to the causes above, some risk factors may increase the risk of SSDs, including:

  • Family history of communication disorders
  • Low parental education level
  • Frequent ear infections
  • Thumb-sucking or pacifier use

Is Speech Sound Disorder Hereditary?

People with a family history of communication disorders have a higher risk of developing SSD themselves, suggesting a possible inherited component to the disorder. However, scientists have not identified a single gene definitively associated with SSDs or other communication disorders. Sometimes a genetic predisposition may work in combination with environmental factors to trigger speech sound disorders.

How Is Speech Sound Disorder Detected?

SSDs typically appear in childhood as children learn how to speak. A certain degree of non-fluency is expected during this early development, making it challenging to spot the earliest signs of the disorder.

Some potential warning signs of SSD include:

  • Problems making and controlling speech movements with the lips, tongue, or jaw
  • Breathlessness while speaking
  • Unusual vocal tone or volume
  • Pronunciation that is atypical for a child of their age
  • Speech that is difficult to understand
  • Problems with non-speech-related mouth movements such as chewing

How Is Speech Sound Disorder Diagnosed?

Diagnosis of SSD begins with determining that the patient has a cluster of symptoms that meet the diagnostic criteria for the disorder. A doctor will start with a physical exam to rule out other problems that may be causing the symptoms. After these exams, if the doctor suspects that SSD is the cause of the symptoms, they may recommend a psychological or psychiatric assessment to solidify the diagnosis.

Diagnostic steps may include:

  • A physical exam. This exam aims at ruling out physical conditions that could be causing the symptoms.
  • Assessment by a speech-language pathologist. This assessment will attempt to understand the person’s ability to speak and understand language.
  • Psychological assessments. If no physical or neurological causes can be found, the doctors may use these assessments to determine if the disorder has a psychological cause. The assessments may take the form of questionnaires or talk sessions with a mental health professional to assess the patient’s mood, mental state, and mental health history. Family members or caregivers may also be asked to participate in these assessments.

The results of the psychological assessments will be compared to the diagnostic criteria for SSD in the Diagnostic and Statistical Manual of Mental Disorders (DSM). The DSM criteria for SSD include:

  • The person has problems with pronunciation that interfere with communication or cause impairment in social, school, work, or other situations.
  • The symptoms begin in early childhood.
  • The symptoms are not better explained by a neurological problem, a medical disorder, a sensory problem, or another mental health-related issue.


How Is Speech Sound Disorder Treated?

Speech therapy is typically the most effective approach to improving SSD symptoms. In cases where an underlying neurological or physical condition causes the disorder, treatment of the underlying condition should also be pursued.

How Does Speech Sound Disorder Progress?

Most people with SSDs will see improvement in their symptoms by adulthood. However, the effects of the disorder in childhood can cause serious mental health and social issues. Potential complications of SSDs include:

  • Low self-esteem
  • Being bullied
  • Problems with schoolwork
  • Impairment of social relationships
  • Anxiety

How Is Speech Sound Disorder Prevented?

There is no known way to prevent an SSD. However, recognizing the disorder early and intervening with treatment may lessen the severity of symptoms and help them resolve more quickly.

Speech Sound Disorder Caregiver Tips

SSDs often exist alongside other mental health and brain-related conditions, a condition called co-morbidity. These disorders are commonly associated with SSDs:

Speech Sound Disorder Brain Science

Scientists have discovered differences in brain structure and activity between people with speech sound disorders and those who don’t have problems with pronunciation. Some of those differences include:

  • One study found that children with speech problems had greater than typical volume in specific parts of the brain, including the corpus callosum and the superior temporal gyrus. The study’s authors suggested that this difference could be evidence of delayed neuronal pruning, a normal process of brain development in which extra nerve cells are eliminated from a child’s brain. The retention of these unnecessary neurons could get in the way of normal language processing.
  • Another study compared brain activity in children with SSD with children without speech difficulties. Functional magnetic resonance imaging (fMRI) studies found that children with SSD had decreased activity in their inferior frontal gyrus and middle temporal gyrus and increased activity in other parts of the brain. The areas with low activity play a role in speech processing and memory for sounds. The authors theorized that the increased activity in other areas might be an attempt to compensate for the deficiencies.

Speech Sound Disorder Research

Title: Correcting Residual Errors With Spectral, Ultrasound, Traditional Speech Therapy (C-RESULTS)

Stage: Recruiting

Contact: Elaine R. Hitchcock, PhD

Montclair State University

Bloomfield, NJ  

Children with speech sound disorder show diminished accuracy and intelligibility in spoken communication and may thus be perceived as less capable or intelligent than peers, with negative consequences for both socioemotional and socioeconomic outcomes. While most speech errors resolve by the late school-age years, between 2-5% of speakers exhibit residual speech errors (RSE) that persist through adolescence or even adulthood, reflecting about 6 million cases in the US. Both affected children/families and speech-language pathologists (SLPs) have highlighted the critical need for research to identify more effective forms of treatment for children with RSE. In a series of single-case experimental studies, research has found that treatment incorporating technologically enhanced sensory feedback (visual-acoustic biofeedback, ultrasound biofeedback) can improve speech in individuals with RSE who have not responded to previous intervention. A randomized controlled trial (RCT) comparing traditional vs. biofeedback-enhanced intervention is the essential next step to inform evidence-based decision-making for this prevalent population. Larger-scale research is also needed to understand heterogeneity across individuals in the magnitude of response to biofeedback treatment.

The overall objective of this proposal is to conduct clinical research that will guide the evidence-based management of RSE while also providing novel insights into the sensorimotor underpinnings of speech. The central hypothesis is that biofeedback will yield greater gains in speech accuracy than traditional treatment and that individual deficit profiles will predict relative response to visual-acoustic vs. ultrasound biofeedback. This study will enroll n = 118 children who misarticulate the /r/ sound, the most common type of RSE. This first component of the study will evaluate the efficacy of biofeedback relative to traditional treatment in a well-powered randomized controlled trial. Ultrasound and visual-acoustic biofeedback, which have similar evidence bases, will be represented equally.


Title: Manipulating Linguistic Complexity to Improve Child Language Treatment Outcomes

Stage: Recruiting

Principal investigator: Jessica A. Barlow, PhD

San Diego State University Speech-Language Clinic

San Diego, CA 

Phonological disorder (PD) and specific language impairment (SLI) directly impact a child’s ability to communicate and are among the most prevalent developmental disorders. The proposed experiments manipulate the complexity of treatment targets to identify the most efficacious treatment approaches for English- and Spanish-speaking children aged 3 to 6 years who present with these disorders. This research will reveal the nature of interactions between sound and structure in language for these children and will have significant implications for a unique approach to target selection when treating persistent phonological and grammatical difficulties in children with PD, SLI, or both.

This proposed research program will evaluate the influence of morpho-phonological interaction in the language of English and Spanish-speaking children with phonological disorder (PD), those with specific language impairment (SLI), and those children with co-occurring PD and SLI (PD-SLI) through manipulation of phonological and morphological complexity in the selection of treatment target words. The proposed research will 1) bridge linguistic theory with clinical treatment to identify ideal targets for generalization learning across populations, 2) focus on both morphology and phonology, which are known to interact in normal systems, and 3) define how these principles together impact on the management of disordered systems. Upon completion of the proposed work, the nature of morpho-phonological interactions within and across the clinical populations will be identified, and the role of (morpho-)phonological complexity in driving change following treatment will be delineated.


Title: A Framework For Linking Sequential Pattern Rules in DLD: Perception in Adults

Stage: Recruiting

Principal investigator: LouAnn Gerken, PhD

University of Arizona

Tucson, AZ

This clinical study aims to assess the hypothesis that morphological and phonological deficits are linked by a broader deficit in sequential pattern learning. This hypothesis applies to learning in general but is especially critical as an avenue for developing earlier assessments and more powerful interventions for children with developmental language disorder (DLD; AKA specific language impairment). Other populations, such as at-risk toddlers, may also benefit from this new approach.

The developmental approach taken here combines what researchers already know about morpho-syntactic deficits in DLD with recent developments in linguistics and language acquisition. First, it is possible to divide phonological and morphological patterns into three pattern types (Single Feature, OR/Disjunction, Family Resemblance/Prototype). These types have a long history of study in visual pattern learning. Importantly, children with DLD appear to have maximum difficulty with morpho-syntactic patterns of the OR type (e.g., regular past tense; add a “t” if the final consonant is voiceless OR a “d” if the final consonant is voiced). In contrast, studies using artificial grammars show that typically developing infants are highly adept at learning Single Feature and OR pattern types; Family Resemblance patterns may be weaker. Family resemblance patterns relate to similarity and may be more closely tied to the lexicon than to grammar (e.g., beagles and terriers are similar, and they are both dogs; the words “goat” and “boat” are similar). Typical adults are adept at Single Feature and Family Resemblance patterns but appear to be, at least superficially, more like children with DLD in their performance on the OR pattern.

With these intriguing findings as a starting point, the proposed research links phonological and morphological sequence learning in children with developmental language disorder (DLD). In the studies focused on children, researchers ask if 4- to 6-year-olds who are typically developing as well as those with DLD (both with and without co-occurring speech sound deficits) and speech sound disorder (SSD; without co-occurring morpho-syntactic deficits) are sensitive to input examples that fit one of these three patterns. Consistent with their long-documented morpho-syntactic deficit, researchers hypothesize that children with DLD will have particular difficulty with the OR pattern. Consistent with their intact morpho-syntactic skills, children with SSD should show no deficits in the OR pattern, revealing a link between OR pattern learning, phonology, and morpho-syntax. The endpoint measure is that children with DLD (both with and without an accompanying SSD) do not show sensitivity to the OR pattern, as measured by sound pattern (e.g., phonetic accuracy, syllable sequence stability) and motor learning (e.g., articulatory and acoustic variability) measures.

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