A speech sound disorder (SSD) is a
speech disorder in which some sounds (
phoneme
In phonology and linguistics, a phoneme () is a unit of sound that can distinguish one word from another in a particular language.
For example, in most dialects of English, with the notable exception of the West Midlands and the north-wes ...
s) are not produced or used correctly. The term "protracted phonological development" is sometimes preferred when describing children's speech, to emphasize the continuing development while acknowledging the delay.
Classification
Speech sound disorders may be subdivided into two primary types, articulation disorders (also called phonetic disorders) and phonemic disorders (also called phonological disorders). However, some may have a mixed disorder in which both articulation and phonological problems exist. Though speech sound disorders are associated with childhood, some ''residual'' errors may persist into adulthood.
Articulation disorders
Articulation disorders (also called phonetic disorders, or simply "artic disorders" for short) are based on difficulty learning to physically produce the intended phonemes. Articulation disorders have to do with the main articulators which are the lips, teeth, alveolar ridge, hard palate, velum, glottis, and the tongue. If the disorder has anything to do with any of these articulators, then it is an articulation disorder. There are usually fewer errors than with a phonemic disorder, and distortions are more likely (though any omissions, additions, and substitutions may also be present). They are often treated by teaching the child how to physically produce the sound and having them practice its production until it (hopefully) becomes natural. Articulation disorders should not be confused with
motor speech disorders, such as
dysarthria (in which there is actual paralysis of the speech musculature) or
developmental verbal dyspraxia (in which
motor planning In psychology and neuroscience
Neuroscience is the science, scientific study of the nervous system (the brain, spinal cord, and peripheral nervous system), its functions and disorders. It is a Multidisciplinary approach, multidisciplinary scien ...
is severely impaired).
List
* ''Deltacism'' is a difficulty in producing ''d'' sound.
* ''Etacism'' is a difficulty in producing ''e'' sound.
* ''Gamacism'' is a difficulty in producing ''g'' sound.
* ''Hitism'' is a difficulty in producing /h/ sound.
* ''Iotacism'' is a difficulty in producing /j/ sound.
* ''Kapacism'' is a difficulty in producing ''k'' sound.
* ''Lambdacism'' (from the
Greek letter
The Greek alphabet has been used to write the Greek language since the late 9th or early 8th century BCE. It is derived from the earlier Phoenician alphabet, and was the earliest known alphabetic script to have distinct letters for vowels as ...
λ) is the difficulty in pronouncing ''l'' and similar sounds.
* ''Rhotacism'' is a difficulty producing ''r'' sounds in the respective language's standard pronunciation.
** In
Czech there is a specific type of rhotacism called ''rotacismus bohemicus'' which is an inability to pronounce the specific sound .
* ''Sigmatism'' is a difficulty of producing ''s'', ''z'' and similar sounds.
* ''Tetacism'' is a difficulty of producing ''t'' sound.
** ''Tetism'' is replacement of ''s'', ''k'' and similar sounds with ''t'' and of ''z'' and similar sounds with ''d''.
Phonemic disorders
In a phonemic disorder (also called a phonological disorder) the child is having trouble learning the sound system of the language, failing to recognize which sound-contrasts also contrast meaning. For example, the sounds /k/ and /t/ may not be recognized as having different meanings, so "call" and "tall" might be treated as
homophones
A homophone () is a word that is Pronunciation, pronounced the same (to varying extent) as another word but differs in meaning. A ''homophone'' may also differ in spelling. The two words may be Spelling, spelled the same, for example ''rose'' ( ...
, both being pronounced as "tall." This is called ''phoneme collapse'', and in some cases many sounds may all be represented by one — e.g., /d/ might replace /t/, /k/, and /g/. As a result, the number of error sounds is often (though not always) greater than with articulation disorders and substitutions are usually the most common error. Phonemic disorders are often treated using ''
minimal pair
In phonology, minimal pairs are pairs of words or phrases in a particular language, spoken or signed, that differ in only one phonological element, such as a phoneme, toneme or chroneme, and have distinct meanings. They are used to demonstrate ...
s'' (two words that differ by only one sound) to draw the child's attention to the difference and its effect on communication.
Some children with phonemic disorders can hear that two phonemes are different from each other when others speak, but are not aware that those phonemes sound the same when they themselves speak. This is called the ''
fis phenomenon'', after a scenario in which a speech pathologist says, "You said 'fis,' did you mean 'fish'?" And the child responds, "No, I didn't say 'fis,' I said 'fis'." In some cases, a child is making sounds which, while similar, are acoustically distinct. Others don’t hear that difference, however,
because the two sounds are not treated as separate phonemes in the language being spoken.
Though phonemic disorders are often considered language disorders in that it is the language system that is affected, they are also speech sound disorders in that the errors relate to use of phonemes. This makes them different from ''
specific language impairment
Specific language impairment (SLI) (the term developmental language disorder is preferred by some) is diagnosed when a child's language does not develop normally and the difficulties cannot be accounted for by generally slow development, physical ...
'', which is primarily a disorder of the
syntax (grammar) and usage of language rather than the sound system. However, the two can coexist, affecting the same person.
Other disorders can deal with a variety of different ways to pronounce consonants. Some examples are glides and liquids. Glides occur when the articulatory posture changes gradually from consonant to vowel. Liquids can include /l/ and /ɹ/.
Mixed speech sound disorders
In some cases phonetic and phonemic errors may coexist in the same person. In such case the primary focus is usually on the phonological component but articulation therapy may be needed as part of the process, since teaching a child how to use a sound is not practical if the child does not know how to produce it.
Residual errors
Even though most speech sound disorders can be successfully treated in childhood, and a few may even outgrow them on their own, errors may sometimes persist into adulthood rather than only being not
age appropriate. Such persisting errors are referred to as "residual errors" and may remain for life.
Presentation
Errors produced by children with speech sound disorders are typically classified into four categories:
*Omissions: Certain sounds are not produced — entire syllables or classes of sounds may be deleted; e.g., fi' for fish or 'at for cat. This differs from features like
non-rhoticity,
h-dropping
''H''-dropping or aitch-dropping is the deletion of the voiceless glottal fricative or "''H''-sound", . The phenomenon is common in many dialects of English, and is also found in certain other languages, either as a purely historical developme ...
or
l-vocalization
''L''-vocalization, in linguistics, is a process by which a lateral approximant sound such as , or, perhaps more often, velarized , is replaced by a vowel or a semivowel.
Types
There are two types of ''l''-vocalization:
* A labiovelar approxi ...
which are part of various regional, national, and ethnic
accent Accent may refer to:
Speech and language
* Accent (sociolinguistics), way of pronunciation particular to a speaker or group of speakers
* Accent (phonetics), prominence given to a particular syllable in a word, or a word in a phrase
** Pitch ac ...
s and are generally not considered disorders.
*Additions (or Epentheses/Commissions): an extra sound or sounds are added to the intended word; e.g. puh-lane for plane.
*Distortions: Sounds are changed slightly so that the intended sound may be recognized but sounds "wrong," or may not sound like any sound in the language.
*Substitutions: One or more sounds are substituted for another; e.g., wabbit for rabbit or tow for cow.
Sometimes, even for experts, telling exactly which type has been made is not obvious — some distorted forms of /ɹ/ may be mistaken for /w/ by a casual observer, yet may not actually be either sound but somewhere in between. Further, children with severe speech sound disorders may be difficult to understand, making it hard to tell what word was actually intended and thus what is actually wrong with it. Some terms can be used to describe more than one of the above categories, such as
lisp
A lisp is a speech impairment in which a person misarticulates sibilants (, , , , , , , ). These misarticulations often result in unclear speech.
Types
* A frontal lisp occurs when the tongue is placed anterior to the target. Interdental lispi ...
, which is often the replacement of /s/ with /θ/ (a substitution), but can be a distortion, producing /s/ just behind the teeth resulting in a sound somewhere between /s/ and /θ/.
There are three different levels of classification when determining the magnitude and type of an error that is produced:
# Sounds the patient can produce
##A: Phonemic- can be produced easily; used meaningfully and contrastively
##B: Phonetic- produced only upon request; not used consistently, meaningfully, or contrastively; not used in connected speech
# Stimulable sounds
##A: Easily stimulable
##B: Stimulable after demonstration and probing (i.e. with a tongue depressor)
# Cannot produce the sound
##A: Cannot be produced voluntarily
##B: No production ever observed
Note that omissions do not mean the sound cannot be produced, and some sounds may be produced more easily or frequently when appearing with certain other sounds: someone might be able to say "s" and "t" separately, but not "st," or may be able to produce a sound at the beginning of a word but not at the end. The magnitude of the problem will often vary between different sounds from the same speaker.
Causes
Most speech sound disorders occur without a known cause. A child may not learn how to produce sounds correctly or may not learn the rules of speech sounds on their own. These children may have a problem with speech development, which does not always mean that they will simply outgrow it by themselves. Many children do develop speech sounds over time but those who do not often need the services of a Speech-Language Pathologist to learn correct speech sounds.
Some speech sound errors can result from other syndromes or disorders such as:
*
developmental disorders (e.g.
autism
The autism spectrum, often referred to as just autism or in the context of a professional diagnosis autism spectrum disorder (ASD) or autism spectrum condition (ASC), is a neurodevelopmental condition (or conditions) characterized by difficulti ...
)
*
genetic disorders (e.g.
Down syndrome
Down syndrome or Down's syndrome, also known as trisomy 21, is a genetic disorder caused by the presence of all or part of a third copy of chromosome 21. It is usually associated with child development, physical growth delays, mild to moderate ...
)
*
hearing loss
Hearing loss is a partial or total inability to hear. Hearing loss may be present at birth or acquired at any time afterwards. Hearing loss may occur in one or both ears. In children, hearing problems can affect the ability to acquire spoken la ...
, including temporary hearing loss, such as from ear infections
*
cleft palate or other physical anomalies of the mouth
* illness
*
neurological disorders (e.g.
cerebral palsy
Cerebral palsy (CP) is a group of movement disorders that appear in early childhood. Signs and symptoms vary among people and over time, but include poor coordination, spasticity, stiff muscles, Paresis, weak muscles, and tremors. There may be p ...
)
Diagnosis
According to the
DSM-5
The ''Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition'' (DSM-5), is the 2013 update to the ''Diagnostic and Statistical Manual of Mental Disorders'', the taxonomic and diagnostic tool published by the American Psychiatric ...
, about 50% of speech from a typical 2-year-old child has may be intelligible. A 4-year-old child's speech should be intelligible overall, and a 7-year-old should be able to clearly produce most words consistent with community norms for their age. Misarticulation of certain difficult sounds ([], [],
[], [], [], [], [], [], and []) may be normal up to 8 years. Children with speech sound disorder have pronunciation difficulties inappropriate for their age, and the difficulties are not caused by
hearing problems, congenital deformities,
motor disorders or
selective mutism
Selective mutism (SM) is an anxiety disorder in which a person who is otherwise capable of speech becomes unable to speak when exposed to specific situations, specific places, or to specific people, one or multiple of which serving as triggers. ...
.
The DSM-5 diagnostic criteria for speech sound disorder require a persistent difficulty with speech sound production since an early developmental age. For diagnosis, this must lead to difficulty in effective communication and tangible negative social outcomes like reduced academic or occupational performance. Diagnosis is ruled out if the underlying cause is a
birth defect
A birth defect, also known as a congenital disorder, is an abnormal condition that is present at birth regardless of its cause. Birth defects may result in disabilities that may be physical, intellectual, or developmental. The disabilities c ...
or acquired condition such as
cerebral palsy
Cerebral palsy (CP) is a group of movement disorders that appear in early childhood. Signs and symptoms vary among people and over time, but include poor coordination, spasticity, stiff muscles, Paresis, weak muscles, and tremors. There may be p ...
,
cleft palate, deafness or hearing loss and
traumatic brain injury
A traumatic brain injury (TBI), also known as an intracranial injury, is an injury to the brain caused by an external force. TBI can be classified based on severity (ranging from mild traumatic brain injury TBI/concussionto severe traumatic b ...
. Other
speech disorders
Speech disorders or speech impairments are a type of communication disorder in which normal speech is disrupted. This can mean stuttering, lisps, etc. Someone who is unable to speak due to a speech disorder is considered mute. Speech skills ...
can be diagnosed along with speech sound disorder, although differential diagnosis with
selective mutism
Selective mutism (SM) is an anxiety disorder in which a person who is otherwise capable of speech becomes unable to speak when exposed to specific situations, specific places, or to specific people, one or multiple of which serving as triggers. ...
can be difficult due to normal speech being observed only in some settings.
Treatment
For most children, the disorder is not lifelong and speech difficulties improve with time and
speech-language treatment. Prognosis is poorer for children who also have a
language disorder, as that may be indicative of a learning disorder.
See also
*
Accent (sociolinguistics)
*
Developmental verbal dyspraxia
Development of the human body is the process of growth to maturity. The process begins with fertilization, where an egg released from the ovary of a female is penetrated by a sperm cell from a male. The resulting zygote develops through mit ...
*
FOXP2
Forkhead box protein P2 (FOXP2) is a protein that, in humans, is encoded by the ''FOXP2'' gene. FOXP2 is a member of the forkhead box family of transcription factors, proteins that regulate gene expression by binding to DNA. It is expressed ...
*
KE family
*
Infantile speech
*
Speech and language pathology
Speech is a human vocal communication using language. Each language uses phonetic combinations of vowel and consonant sounds that form the sound of its words (that is, all English words sound different from all French words, even if they are th ...
References
Further reading
*
*
*
*
Bowen, C. (2009). Children's speech sound disorders Oxford: Wiley-Blackwell
Raz, M. (1992). How to Teach a Child to Say the "S" Sound in 15 Easy Lessons.GerstenWeitz Publishers
Raz, M. (1996). How to Teach a Child to Say the "R" Sound in 15 Easy Lessons.GerstenWeitz Publishers
Raz, M. (1999). How to Teach a Child to Say the "L" Sound in 15 Easy Lessons.GerstenWeitz Publishers
External links
Children's Speech Sound Disorders
{{Dyslexia and specific developmental disorders
Communication disorders
Speech disorders
Speech and language pathology
Speech error
Language disorders