What Causes Speech Sound Disorders? Known Causes and Risk Factors
Most speech sound disorders have no known cause — ASHA calls them idiopathic. Others are organic: caused by a motor or neurological condition such as apraxia, a structural difference such as cleft palate, or a sensory problem such as hearing loss. Risk factors include being male, family history, and birth problems.
Idiopathic vs. organic
ASHA divides speech sound disorders into two groups. Idiopathic speech sound disorders have no known cause; they cover what used to be called articulation and phonological disorders, and they are the focus of most children’s speech therapy. Organic speech sound disorders result from an identifiable condition.1
| Type | Cause | Examples |
|---|---|---|
| Organic — motor/neurological | A condition affecting the planning or control of speech movements | Childhood apraxia of speech; dysarthria |
| Organic — structural | A difference in the structures used for speech | Cleft lip and palate; other structural anomalies |
| Organic — sensory/perceptual | A problem hearing or perceiving speech | Hearing loss |
| Idiopathic | No known cause | Articulation disorders; phonological disorders |
Organic and idiopathic speech sound disorders (ASHA Practice Portal).1
Risk factors for idiopathic speech sound disorders
Even without a known cause, some children are more likely to have a speech sound disorder. ASHA lists these frequently reported risk factors:1
- Biological sex — speech sound disorders are more common in boys.
- Pre- and perinatal problems — maternal stress or infections in pregnancy, delivery complications, preterm birth, and low birthweight.
- Family history — parents or siblings with speech or language difficulties.
- Persistent ear fluid (otitis media with effusion), often associated with hearing loss.
A large UK cohort study adds early warning signs for problems that last: weak sucking at 4 weeks, not often combining words at 24 months, and being unintelligible to strangers at 38 months were among the early predictors of a persistent speech sound disorder at 8.4
ASHA also notes that protective and social factors — access to early intervention, language-rich environments, access to health care, and parental education and engagement — can influence outcomes.1
Free Speech Delay Quiz
A 20-question screener that returns a clear risk score and next steps.
Differences that are not disorders
ASHA is explicit that everyone speaks with an accent and uses one or more dialects. A child’s speech is judged against the sounds and rules of the languages and dialects they use — not against mainstream American English — and dialect features, such as marking plurals differently, should not be mistaken for an error pattern.1
Why the cause changes the plan
- Hearing loss: an audiologist and hearing management come first; ASHA says hearing should be checked to rule out hearing loss.
- Cleft palate: structural problems need physical management such as surgery, while learned compensatory errors respond to speech therapy, coordinated by a cleft team.
- Childhood apraxia of speech: NIDCD says frequent, intensive, one-on-one therapy is needed.
- Idiopathic: speech therapy targets the sounds and patterns themselves.
These distinctions come from ASHA’s guidance on hearing and on cleft palate, and NIDCD’s guidance on apraxia. MedlinePlus likewise lists structural changes such as cleft palate, nerve or brain damage such as cerebral palsy, and hearing loss among causes of articulation and phonological disorders.2,7,6,5,3
Frequently asked questions
What causes a speech sound disorder?＋
Usually nothing that can be identified. ASHA says the cause of idiopathic speech sound disorders is not known. Organic speech sound disorders have a known cause: motor or neurological conditions (such as childhood apraxia of speech or dysarthria), structural differences (such as cleft lip and palate), or sensory problems (such as hearing loss).
Are speech sound disorders genetic?＋
They run in families. ASHA lists family history as a frequently reported risk factor: children whose parents or siblings have speech or language difficulties are more likely to have a speech disorder. MedlinePlus also notes articulation and phonological disorders may occur in other family members.
Did I cause my child’s speech problem?＋
ASHA says the cause of idiopathic speech sound disorders is not known. The risk factors it lists are sex, pre- and perinatal problems, family history, and persistent ear fluid, and it notes that supportive factors — language-rich environments, parental engagement, and access to early intervention — can influence outcomes.
Is an accent or a second language a cause?＋
No — an accent or dialect is a difference, not a disorder. ASHA says the presence of a speech sound disorder is determined by the rules of the languages and dialects a child uses, not by comparison to mainstream American English.
Put this into practice today
Try the free speech delay quiz, or start daily AI speech practice — every child takes one SpeechStep at a time.
References
7 sources from authoritative bodies. Last reviewed October 2026.
- 1.ASHASpeech Sound Disorders: Articulation and Phonology — Practice Portal page.
- 2.ASHASpeech Sound Disorders — Consumer page.
- 3.MedlinePlus (U.S. National Library of Medicine)Speech disorders - children — Medical encyclopedia.
- 4.Peer-reviewedWren et al. — Prevalence and Predictors of Persistent Speech Sound Disorder at Eight Years Old — Population cohort study (JSLHR), 2016.
- 5.NIDCDApraxia of Speech — Fact sheet.
- 6.ASHACleft Lip and Palate — Practice Portal page.
- 7.ASHAEffects of Hearing Loss on Development — Consumer page.