Speech Sound Disorders: Nine Essential Statistics

Blog #4 in the Phonology Means Nothing and Other Astounding and Very Practical Facts about Speech Sound Disorders Blog Series

For more information about this series, see the Phonology Means Nothing Series welcome page

By Ken Bleile, PhD
May 15, 2020

The following nine statistics give “the big picture” on how speech sound disorders may impact the life of a child:

1. A speech sound disorder is the world’s most common type of communication disorder, affecting approximately 10% to 15% of preschoolers and 6% of students (American Speech-Language-Hearing Association, 2006; Campbell et al., 2003; Law, Boyle, Harris, Harkness, & Nye, 2000; Shriberg & Tomblin, 1999; Slater, 1992).

What This May Mean: If you choose to work in pediatric settings, expect your caseload to include many children with speech sound disorders.

2. Speech sound disorders are sufficiently severe that nearly four out of five children require treatment (Gierut, 1998).

What This May Mean: Don’t expect most children with speech sound disorders to “get over it” without professional assistance.

3. At least three quarters of preschoolers with speech sound disorders also have language difficulties (Paul & Shriberg, 1982; Ruscello, St. Louis, & Mason, 1991; Shriberg & Kwiatkowski, 1988).

What This May Mean: Most preschoolers you see for speech sound disorders also need your help in language.

4. A toddler or a preschooler with a speech sound disorder is at increased risk for later academic difficulties during the school years (Anthony et al., 2011; Bird, Bishop, & Freeman, 1995; Felsenfeld, Broen, & McGue, 1994; Shriberg & Kwiatkowski, 1994; Shriberg, Lewis, Tomblin, McSweeny, Karlsson, & Scheer, 2005; Van Dyke & Holte, 2003).

What This May Mean: Consider a speech sound disorder in a preschooler to be a “red flag” for possible future academic difficulties.

5. Preschoolers with speech sound disorders have a higher risk for school challenges if they also have language problems, lower nonverbal intelligence, and social disadvantages (Lewis et al., 2015).

What This May Mean: Your “clinical alarm bells” for future school challenges should go off loudly if a preschooler with a speech sound disorder also has language problems, has lower nonverbal intelligence, or comes from a deeply impoverished or neglectful environment.

6. Approximately 11% to 15% of 6-year-old students with speech sound disorders also experience specific language impairment (Shriberg & Tomblin, 1999).

What This May Mean: Evaluate language along with speech, because a first grader referred to you for speech may also have language difficulties.

7. Half or more of students with speech sound disorders struggle academically all the way through high school (Gierut, 1998; Felsenfeld et al., 1994; Lewis, Freebairn, & Taylor, 2000; Pennington & Bishop, 2009; Shriberg & Austin, 1998).

What This May Mean: Plan that your students with speech sound disorders will probably need academic assistance throughout school to reach their best potential.

8. Even when a student with reduced intelligibility does well in school, one third of grade school teachers perceive them as having less overall academic potential than their classmates (Overby, Carrell, & Bernthal, 2007).

What This May Mean: The self-image of your student may be “bruised” by the fact that many people falsely believe that their speech difficulties reflect “lack of intelligence.”

9. A student with a speech sound disorder is at risk for being bullied, struggling with friendships, and enjoying school less (McCormack, Harrison, McLeod, & McAllister, 2011).

What This May Mean: Keep your eyes open to the possibility that your student with a speech sound disorder is being ostracized, is socially isolated, or is being bullied.


American Speech-Language-Hearing Association. (2006). 2006 Schools Survey report: Caseload characteristics. Rockville, MD: Author.

American Speech-Language-Hearing Association. (2010). 2010 Schools summary report: Number and type of responses, SLPs. Rockville, MD: Author.

Anthony, J. L., Aghara, R. G., Dunkelberger, M. J., Anthony, T. I., Williams, T. I., & Zhang, Z. (2011). What factors place children with speech sound disorders at risk for reading problems? American Journal of Speech-Language Pathology, 20, 146–160.

Bird, J., Bishop, D., & Freeman, N. (1995). Phonological awareness and literacy development in children with expressive phonological impairments. Journal of Speech and Hearing Research, 38, 446–462.

Campbell, T., Dollaghan, C., Rockette, H., Paradise, J., Feldman, H., Shriberg, L., Sabo, D., & Kurs-Lasky, M. (2003). Risk factors for speech delay of unknown origin in 3-year-old children. Child Development, 74, 346–357.

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Felsenfield, S., Broen, P., & McGue, M. (1994). A 28-year follow-up of adults with a history of moderate phonological disorder: Educational and functional results. Journal of Speech and Hearing Research, 37, 1341–1353.

Gierut, J.A. (1998). Treatment efficacy: Functional phonological disorders in children. J Speech Lang Hear Res, 41, S85-100.

Law, J., Boyle, J., Harris, F., Harkness, A., & Nye, C. (2000). Prevalence and natural history of primary speech and language delay: Findings from a systematic review of the literature. International Journal of Language and Communication Disorders, 35, 165–188.

Lewis, B., Freebairn, L., & Taylor, H. (2000). Academic outcomes in children with histories of speech sound disorders. Journal of Communication Disorders, 33, 11–30.

Lewis, B., Freebairn, L., Tag, J., Ciesla, A., Iyengar, S., Stein, C., & Taylor, H. (2015). Adolescent outcomes of children with early speech sound disorders with and without language impairment. American Journal of Speech Language Pathology, 24, 150–163.

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Overby, M., Carrell, T., & Bernthal, J. (2007). Teachers’ perceptions of students of students with speech sound disorders: A quantitative and qualitative analysis. Language, Speech, and Hearing in the Schools, 38, 327–341.

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Shriberg, L. D., & Kwiatkowski, J. (1988). A follow-up study of children with phonologic disorders of unknown origin. Journal of Speech and Hearing Disorders, 53, 144–155.

Shriberg, L. D., Lewis, B. A., Tomblin, J. B., McSweeny, J. L., Karlsson, H. B., & Scheer, A. R. (2005). Toward diagnostic and phenotype markers for genetically transmitted speech delay. Journal of Speech, Language, and Hearing Research, 48, 834–852.

Shriberg, L., & Tomblin, B. (1999). Prevalence of speech delay in 6-year-old children and comorbidity with language impairment. Journal of Speech, Language, and Hearing Research, 42, 1461–1481.

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Van Dyke, D. C., & Holte, L. (2003). Communication disorders in children. Pediatric Annals, 32, 436.