Incidence and Prevalence of Communication Disorders and Hearing Loss in Children – 2008 Edition
Communication disorders are among the most common disabilities in the United States. A child's overall future and success can be improved greatly through the early identification of communication disorders, establishment of their causes, and subsequent intervention (1).
A speech disorder is an impairment of the articulation of fluency, speech sounds, and/or voice (2).
- The number of children with disabilities, ages 3–21, served in the public schools under the Individuals with Disabilities Education Act (IDEA) Part B in Fall 2003 was 6,068,802 (in the 50 states, DC, and outlying areas). Of these children, 1,460,583 (24.1%) received services for speech or language disorders. This estimate does not include children who have speech/language problems secondary to other conditions (3).
- Case histories often reveal a positive family history of communication disorders. Between 28% and 60% of children with a speech and language deficit have a sibling and/or parent who is also affected (4).
A fluency disorder is a speech disorder characterized by deviations in continuity, smoothness, rhythm, and/or effort with which phonologic, lexical, morphologic, and/or syntactic language units are spoken (5).
- Incidence of childhood stuttering is highest between a child's second and fourth birthdays, ultimately affecting 4% to 5% of the population (6, 7).
- Although the ratio of boys to girls who begin to stutter between the ages of two and four is approximately equal, girls are more likely to experience unassisted recovery. As such, the ratio of boys to girls who persist in stuttering increases to approximately 3 to 1 (7).
- When recovery occurs, it is likely to do so from 6 to 36 months after onset, with most children recovering within the first 1 to 2 years after their stuttering was first noted (7).
- Males are more likely to exhibit co-occurring speech disorders than females, especially in articulation and phonology. Co-occurring non-speech-language disorders are also significantly higher in males than females (8).
- In 2006, almost 69% of speech-language pathologists in schools indicated that they served individuals with fluency disorders (9).
Voice disorders are characterized by the abnormal production and/or absence of vocal quality, pitch, loudness, resonance, and/or duration, given an individual's age and/or sex (2).
- Early identification of pediatric disfluency and voice disorders is advisable because these disorders may progress to lifelong communicative impairments if left untreated (10).
- Vocal disturbances in children are surprisingly common. A child who presents with hoarseness demands a rapid and thorough assessment (11). Reported occurrence of hoarseness range from 6% to 23% in school-aged children (12).
- Voice disorders in children may impede their academic performance and their socialization in school. Moreover, the majority of adult voice disorders are thought to begin during childhood (12).
- Children with voice disorders do respond to treatment, with vocal hyperfunction being the predominant caseload pf the pediatric voice clinician (13).
- In 2006, approximately 29% of speech-language pathologists indicated that they served individuals with voice/resonance disorders (9).
A language disorder is the impaired comprehension and/or use of spoken, written, and/or other symbol systems. The disorder may involve the form, content, and/or function of language in communication (2).
- Children with early development language impairment demonstrate persistent impairments in developmental and functional skills at school entry not limited to language (14).
- Moderate to severe language difficulties in young children, particularly those affecting language comprehension, are predictive of long-term problems affecting learning, school achievement, and behavior (15, 16).
- Most children with severe language difficulties are probably identified before they start school, but many may not be identified until they start formal education (15). Estimates of the prevalence of language difficulty in preschool children are between 2% and 19% (17).
- Specific Language Impairment (SLI) occurs when children present language maturation at least 12 months behind their chronological age, in the absence of sensory or intellectual defects, pervasive developmental disorders, evident cerebral damage, and adequate social and emotional conditions (18).
- SLI is one of the most common childhood disorders, affecting 7% of children (19).
- It is common to find associated impairments in motor skills, cognitive function, attention, and reading in children who meet the criteria for SLI. There is evidence that limitation in phonologic working memory may be a core deficit in SLI. Both genetic and environmental factors have also been shown to be important etiologic factors (20).
- Substantial evidence illustrates possible familial transmission of SLI. The incidence in families with a history of SLI is estimated at 20%-40% (21).
- SLI has a prevalence of approximately 7% in children entering school and is associated with later difficulties in learning to read (22).
- In 2006, approximately 61% of speech-language pathologists in schools indicated that they served individuals with SLI (9).
A phonological disorder is an impaired comprehension of the sound system of a language, and the rules that govern the sound combinations (2).
- For 80% of children with phonological disorders, the disorders are sufficiently severe to require clinical treatment (23).
- There is an observed relationship between early phonological disorders and subsequent reading, writing, spelling, and mathematical abilities (23).
- Children with phonological disorders often require other types of remedial services, with 50% to 70% exhibiting general academic difficulty through grade 12 (23).
- In 2006, almost 91% of speech-language pathologists in schools indicated that they served individuals with phonological/articulation disorders (9).
A hearing disorder is the result of impaired auditory sensitivity of the physiological auditory system which may limit the development, comprehension, production, and/or maintenance of speech and/or language (2).
- The number of children with disabilities, ages 3–21, served in the public schools under the Individuals with Disabilities Education Act (IDEA) Part B in Fall 2003 was 6,068,802 (in the 50 states, DC, and outlying areas). Of these children, 79,522 (1.3%) received services for hearing. However, the number of children with hearing loss and deafness is undoubtedly higher, since many of these students may have other disabilities as well (3).
- Several studies indicate variance in the prevalence of newborns with congenital hearing loss in the United States. The overall estimates are between 1 to 6 per 1,000 newborns (24-26). Most children with congenital hearing loss have hearing impairment at birth and are potentially identifiable by newborn and infant hearing screening. However, some congenital hearing loss may not become evident until later in childhood (25).
- Without early detection programs, the average age of identification for hearing loss ranges from 1.5 to 3 years of age (26). More severe hearing impairment, but not later diagnosis, has been correlated to poorer language outcomes at 7-8 years of age (27).
Genetic Hearing Impairment
- About half of the cases of childhood hearing loss are believed to be from genetic causes (28).
- The prevalence of genetic hearing loss has been calculated at approximately 1 in 2,000 (28).
Otitis media (OM) is an infection of the middle ear.
- Otitis media is the most frequently diagnosed disease in infants and young children (29).
- Children with recurrent or prolonged middle ear diseases during the first five years of life tend to be at greater risk for delayed reading than aged-matched peers who have no previous middle ear diseases (30).
- According to one study, pediatricians do not necessarily agree that OM has an impact on speech-language-hearing development. Pediatricians report an early OM onset (birth to age 2) affects speech-language development, but they also report that parents and daycare environments could mitigate any OM effect. Pediatricians state a possible OM impact on hearing status, but are not in agreement that an OM history requires referral for audiological testing (31).
The fields of speech-language pathology and audiology have taken individualistic attitudes toward impairment of communication that encompasses a description of the communicative process, development, difference, disorders, and treatment, as well as the implications of impairment for the person's psychological, sociological, and educational growth. Following the establishment of programs to address various disabilities, it became apparent that many children with special needs did not fit the traditional categories for the handicapped (32). Following are several populations who may have communication disorders secondary to another disability.
Please refer to the report Communication Facts, Special Populations: Autism.
The National Joint Committee on Learning Disabilities (LD) defines LD as a "general term to refer to a heterogeneous group of disorders manifested by significant difficulties in the acquisition and use of listening, speaking, reading, writing, reasoning, or mathematical skills" (33).
- Almost 3 million school children (43.8%) ages 3 to 21 have some form of learning disability and receive special education in school (3).
- The percent of children with a learning disability in the lowest income group is more than double that of the highest income group (34).
- According to one study, the lifetime prevalence of learning disability in US children is almost 10% (35).
Please refer to the report Communication Facts, Special Populations: Literacy.
- Van Dyke, D. C., & Holte, L. (2003, July). Communication disorders in children. Pediatric Annals, 32(7): 436.
- ASHA Ad Hoc Committee on Service Delivery in the Schools. (1993, March). Definitions of communication disorders and variations. Asha, 35 (Suppl. 10), 40–41.
- U.S. Department of Education. (2005). To assure the free appropriate public education of all Americans: Twenty-seventh annual report to Congress on the implementation of the Individuals with Disabilities Education Act. Accessed January 16, 2008, http://www.ed.gov/about/reports/annual/osep/2005/index.html.
- Fox, A. V., Dodd, B., & Howard, D. (2002). Risk factors for speech disorders in children. International Journal of Language & Communication Disorders, 37(2): 117–131.
- American Speech-Language-Hearing Association Special Interest Division 4: Fluency and Fluency Disorders. (1999, March). Terminology pertaining to fluency and fluency disorders: Guidelines. Asha, 41 (Suppl.19): 29–36.
- Andrews, G. (1984). The epidemiology of stuttering. In R. F. Curlee & W. H. Perkins (Eds.). Nature and treatment of stuttering: New directions. San Diego, CA: College-Hill Press.
- Zebrowski, P. M. (2003, July). Developmental stuttering. Pediatric Annals, 32(7): 453–458.
- Blood, G. W., Ridenour, V. J., Qualls, C. D., & Hammer, C. S. (2003, November-December). Co-occurring disorders in children who stutter. Journal of Communication Disorders, 36(6): 427–448.
- ASHA. (2006). 2006 Schools Survey report: Caseload characteristics. Rockville, MD: Author.
- Baker, B. M., & Blackwell, P. B. (2004, March–April). Identification and remediation of pediatric fluency and voice disorders. Journal of Pediatric Health Care, 18(2): 87–94.
- McMurray, J. S. (2003, April). Disorders of phonation in children. Pediatric Clinics of North America, 50(2): 363–380.
- Faust, R. A. (2003, January/February). Childhood voice disorders: Ambulatory evaluation and operative diagnosis. Clinical Pediatrics, 42, 1–9.
- Hooper, C. R. (2004, October). Treatment of voice disorders in children. Language, Speech, & Hearing Services in Schools, 35(4): 320–326.
- Shevell, M. I., Majenmer, A., et. Al. (2005, April). Outcomes at school age of preschool children with developmental language impairment. Pediatric Neurology, 32(4): 264–269.
- Laing, G. J., Law, J., Levin, A., et. al. (2002, November 16). Evaluation of a structured test and a parent led method for screening for speech and language problems: Prospective population based study. British Medical Journal, 325, 1152–1156.
- Chaimay, B., Thinkhamrop, B., & Thinkhamrop, K. (2006, July). Risk factors associated with language development problems in childhood—A literature review. Journal of the Medical Association of Thailand, 89(7): 1080–1086.
- Nelson, H. D., et. al. (2006, February). Screening for speech and language delay in preschool children: Systematic evidence review for the US Preventive Services Task Force. Pediatrics, 117(2): e298–e319.
- de Vasconcelos Hage, S.R., et. al. (2006, June). Specific Language Impairment: Linguistics and neurological aspects. Arquivos de Neuro-Psiquiatria, 64(2A): 173–180.
- Ziegler, J. C., et. al. (2005, September 27). Deficits in speech perception predict language learning impairment. Proceedings of the National Academy of Sciences of the United States of America, 102(3a): 14110–14115.
- Webster, R. I., & Shevell, M. I. (2004, July). Neurobiology of specific language impairment. Journal of Child Neurology, 19(7): 471–481.
- Choudhury, N., & Benasich, A. A. (2003, April). A family aggregation study: the influence of family history and other risk factors on language development. Journal of Speech Language, Hearing Research, 46(2): 261–272.
- Bartlett, C. W., Flax, J. F., Logue, M. W., et. Al. (2002, July). A major susceptibility locus for special language impairment is located on 13q21. American Journal of Human Genetics, 71(1): 45–55.
- Gierut, J. A. (1998, February). Treatment efficacy: Functional phonological disorders in children. Journal of Speech, Language, and Hearing Research, 41, S85–S100.
- Thompson, D. C., et. al. (2001, October 24/31). Universal newborn hearing screening: Summary of evidence. JAMA, 286(16): 2000–2010.
- Cunningham, M., & Cox, E. O. (2003, February). Hearing assessment in infants and children: Recommendations beyond neonatal screening. Pediatrics, 111(2): 436–440.
- No Author. (2003, October 17). Infants tested for hearing loss—United States, 1999–2001. Morbidity and Mortality Weekly Report, 52(41): 981–984.
- Wake, M., Poulakis, Z., Hughes, E. K., et. al. (2005, March). Hearing impairment: a population study of age at diagnosis, severity, and language outcomes at 7–8 years. Archives of Disease in Childhood, 90(3): 238–244.
- Canalis, R. F., & Lambert, P. R. (2000). The ear: Comprehensive otology. Philadelphia, PA: Lippincott Williams & Williams.
- Dhooge, I. J. (2003, July). Risk factors for the development of otitis media. Current Allergy and Asthma Reports, 3(4): 321–325.
- Golz, A., Netzer, A., Westerman, S. T., et. al. (2005, March). Reading performance in children with otitis media. Otolaryngology Head & Neck Surgery, 132(3): 495–499.
- Sonnenschein, E., & Cascella, P. W. (2004, July-August). Pediatricians' opinions about otitis media and speech-language-hearing development. Journal of Communication Disorders, 37(4): 313–323.
- ASHA. (1976, May). Learning disabilities. Asha, 18, 282–290.
- National Joint Committee on Learning Disabilities (1990/94). Learning disabilities: Issues on definition. In Collective Perspectives on Issues Affecting Learning Disabilities: Position Paper and Statements (pp.61–66). Austin, TX: Pro-Ed.
- Blackwell, D. L., & Tonthat, L. (2003). Summary health statistics for U.S. children: National Health Interview Survey, 1999. National Center for Health Statistics. Vital Health Stat 10 (210).
- Altarac, M., & Saroha, E. (2007, February). Lifetime prevalence of learning disability among US children. Pediatrics, 119 (Suppl. 1): S77–S83.
Compiled by Andrea Castrogiovanni * American Speech-Language-Hearing Association * 2200 Research Boulevard, Rockville, MD 20850 * firstname.lastname@example.org