Speech Sound Disorder is a common developmental disorder characterized by deficits in sound production due to motor-based problems, or articulation of speech, as well as deficits that have to do with knowledge and use of speech sounds and patterns.
These deficits are not a product of language impairment or other physiological anomalies. While the disorder is associated with good prognoses and responsiveness to treatment, it may cause functional consequences, and is often associated with poor literacy acquisition and reading difficulties that are likely to be persistent in nature.
Epidemiological data points towards a male predominance in the prevalence of Speech Sound Disorder. The onset begins in childhood, and symptoms may be observed through a failure to meet speech-related developmental milestones, or an inability to match equal-aged children in speaking ability. The etiology of the disorder is unclear, but research has highlighted the association of genetic, demographic, and environmental factors.
Treatment for Speech Sound Disorders is largely based in forms of speech therapy, with phonological intervention being the mainstay of management.
Signs and Symptoms
The signs and symptoms of Speech Sound Disorder may include:
- Difficulty pronouncing words clearly
- Speaking with a lisp
- Difficulty coordinating mouth movements in order to properly pronounce words
Epidemiological studies have revealed a male predominance in the prevalence of Speech Sound Disorder. The symptoms are observable through the inability of children to meet developmental milestones with regards to speech.
Speech is generally understandable by the age of 4, while clear articulation generally occurs between ages 7-8. Difficulties with articulation and continued use of immature phonology is considered problematic beyond age 8. Commonly mispronounced sounds include l, r, s, z, th, ch, dzh, and zh sounds.
The exact cause of the disorder is unknown, though genetic, socio-demographic, and environmental factors are implicated.
A significant genetic factor exists, with a family history of speech or language disorders being associated with a higher risk of developing Speech Sound Disorder. Speculations of a link between the risk loci of Reading Disorder and Speech Sound Disorder have also been made. Perinatal factors are also largely taken into account.
Delays in early language development have also been associated with later occurrence of Speech Sound Disorder. Certain other developmental factors have also been implicated in the etiology of Speech Sound Disorder, including use of pacifiers, delay in motor skills, low birth weight, and medical conditions.
A considerable role is also played by environmental and demographic factors. Maternal education and socioeconomic status have been inversely associated with higher risks of developing Speech Sound Disorder. Further, lower language levels, family size, overcrowding in homes, absence of pre-school education, bilingualism, and multilingualism have also been considered in concordance with the development of the disorder.
The diagnosis of Speech Sound Disorder is usually carried out with the help of adequate screening tools and questionnaires. The clinical history of the individual is of great importance in order to determine whether or not developmental milestones were met in time, as well as to assess the possible predictive factors of the disorder.
Various assessment measures, computerized analysis procedures, analysis of children’s speech samples, and assessment of non-native speakers may be undertaken while trying to determine the diagnosis. The complete process may include hearing screenings, contextual testing, classroom observations, and standardized tests.
The DSM-5 mentions the following criteria for the diagnosis of Speech Sound Disorder:
- Persistent difficulty with speech sound production that interferes with speech intelligibility or prevents verbal communication of messages.
- The disturbance causes limitations in effective communication that interfere with social participation, academic achievement, or occupational performance, individually or in any combination.
- Onset of symptoms is in the early developmental period.
- The difficulties are not attributable to congenital or acquired conditions, such as cerebral palsy, cleft palate, deafness or hearing loss, traumatic brain injury, or other medical or neurological conditions.
Treatment for Speech Sound Disorder usually takes place through some form of Speech Therapy. One of the mainstays of intervention for Speech Sound Disorder is through Phonological Intervention, which includes various tasks such as single-world elicitation which involves sets of pictures being shown to the patient at certain intervals, with objects displayed on them of varying intervals.
Phonological awareness measures may also be carried out, testing the ability of patients to be able to differentiate between various sounds, as well as identification of syllables. Focus may be given to development of phonemic skills, letter-sound knowledge training, reflection on phonological tasks, and general language instruction.
The efficacy of visual biofeedback techniques have also been tested, especially in the case of individuals who don’t respond to intervention. Auditory feedback is often given in order to assist individuals in altering inaccurate speech.
Visual biofeedback allows for a visual representation of the speech patterns of the individual, with a model of correct speech patterns displayed for a comparative overview. This representation of accurate speech can facilitate improvement of speech errors.
Primary healthcare specialists may make initial assessments with respect to gaps in the development of speech through the means of case history and basic screening measures. Speech-language pathologists are usually involved in further diagnosis and treatment.