Updated on February 9, 2024
7 min read

What Causes Lisping?

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A lisp is a speech disorder that affects how someone pronounces certain sounds. 

Lisps commonly develop during childhood. Nearly 1 in 12 children between the ages of 3 and 17 had a disorder related to voice, speech, or swallowing in 2012.1 

Speech disorders, including lisps, are most prevalent in children between the ages of 3 and 6, at 11%.2 Many children grow out of their lisps, though some may persist for years, even into adulthood. 

Persistent lisps may require treatment from a speech-language pathologist, also known as a speech therapist. A speech therapist can identify the cause and type of your child’s lisp and treat it.

What Causes Lisping?

Lisping is a functional speech impediment, meaning it doesn’t have an identified origin. However, there are some possible causes of lisping, including:

  • Learning how to say certain sounds incorrectly
  • Jaw alignment issues
  • Tongue tie or ankyloglossia, when the tongue is tethered to the bottom of the mouth, causing limited mobility
  • Pacifier use or thumbsucking
Ankyloglossia. tongue tie. congenital oral anomaly

Speech professionals debate the actual cause of lisping, but it’s possible to treat a lisp if your child doesn’t grow out of it.

What are the Different Types of Lisps?

Speech-language pathologists categorize lisps into four different types:

  1. Frontal lisp – someone with a frontal lisp pushes their tongue too far forward, causing a mispronunciation of S or Z as a “th” sound. Frontal lisps are the most common type.
  2. Lateral lisp – in a lateral lisp, extra air slips over the sides of the tongue, making S and Z sound “wet”. It may sound like someone with a lateral lisp has excess saliva in their mouth.
  3. Palatal lisp – palatal lisps involve touching the tongue to the roof of the mouth, especially during S, Z, and sometimes R sounds.
  4. Dental lisp – dental and frontal lisps sound very similar. However, in a dental lisp, an individual pushes their tongue against their teeth instead of past them.

A speech therapist will identify which type of lisp your child has. Knowing the type will help them create a treatment plan to correct it.

Symptoms of a Lisp

Lisp symptoms are almost always what you hear in your child’s speech. The most common indicators of a lisp include:

  • Pronouncing S and Z sounds as “th” (frontal or dental)
  • A wet, slushy sound accompanying S and Z (lateral) 
  • An H sound preceding S and Z (palatal)

Lisps don’t typically cause any symptoms unrelated to speech. However, children with lisps may also have:

  • Structural irregularities in the tongue and palate
  • Jaw issues such as an excessive overbite
  • Abnormalities in the teeth, like an excessive overjet
  • Hearing difficulties
  • Delayed development
  • Recent stress or trauma
  • Prolonged respiratory illnesses

While these are not necessarily causes of a lisp, you may see them in conjunction with a lisp.

When to Worry About a Lisp

Most children outgrow their lisps after their toddler years. If your child’s lisp persists past age 5, consult a speech-language pathologist.3

A speech therapist will evaluate your child’s lisp and determine its type. They’ll then formulate a treatment plan designed to correct the lisp. If they find that something structural is causing the lisp, such as a dental issue, they may refer you to another specialist.

When to See a Speech-Language Pathologist

Most children outgrow a lisp and confidently say all speech sounds by age 5. If they have a lisp past that age, you may wish to see a speech-language pathologist, especially if the lisp causes discomfort or self-esteem issues.

Finding a speech therapist in your area is easy. Many public schools employ speech-language pathologists that can see your children as part of their school day. You can ask your doctor for a referral, check local rehabilitation centers, or contact therapy clinics.

The American Speech-Language and Hearing Association (ASHA) also has an excellent search tool for finding a speech therapist near you.

5 Ways to Correct a Lisp

Research shows that speech-language interventions are highly effective. One study found that an average of just 6 hours of speech therapy over 6 months can produce a significant improvement.4

Some of the techniques that speech-language pathologists use to correct a lisp are:

1. Developing awareness

The first step in correcting a lisp is to teach your child to recognize the difference between how they pronounce words versus how others do. They may need help to hear their lisp on their own.

A speech therapist will demonstrate both speaking methods and have your child differentiate between them. You can practice this exercise at home with your child, too.

2. Learning tongue placement

Once your child can hear their lisp, their speech therapist will teach them how to form proper pronunciations. They will educate you and your child on correctly placing their tongue.

Demonstrating and practicing tongue placement is an exercise you can do at home.

3. Practicing words

Now that your child knows how and where to place their tongue, the speech therapist will have them practice words that trigger their lisp.

For example, if S is a problem sound, they will have them practice words that contain the same sound. They might start with words that begin with S, then move on to words with S in the middle or at the end.

4. Working on phrases

After your child has mastered words, they’ll move on to short phrases. These phrases will contain more difficult words.

A speech therapist may linger on this step until your child has fully mastered the phrases and words that give them trouble.

5. Having conversations

Lastly, your child and their speech therapist will practice having entire conversations together. A conversation will combine everything they’ve worked on together during treatment. 

At this point, your child should be able to say difficult words without lisping. If you want to practice this at home, you can have your child:

  • Tell you a story about their day
  • Teach you how to do something
  • Identify pictures or objects around the house

Other Treatments for Lisping

You may hear about other treatments for a lisp, such as having your child drink through a straw. However, using objects such as straws for speech therapy is controversial, as there’s limited evidence of its effectiveness.5

How to Cope With a Lisp

Lisping can have an impact on your child’s confidence and self-esteem. Other children may tease them for their lisp, which could interfere with their school and social life. 

It can also be frustrating to deal with a lisp as an adult. Research shows that a lisp impacts how people view your speaking ability, intelligence, and employability.6

Here are a few tips on how to cope with a lisp for adults and children:

  • Seek treatment — speech therapy can build your confidence and correct your lisp.
  • Get support — seek psychotherapy for you or your child if you need help navigating social situations.
  • Set boundaries — ask friends and family not to make fun of any type of speech impediment, developmental issue, or disability.

Can Lisping Cause Other Problems? 

While lisping may lead to some peer bullying, it generally does not cause any physical issues. Your child’s health is not necessarily at risk simply because they have a lisp.

However, lisps can indicate an underlying issue, such as a tongue tie. It’s always wise to get your child’s lisp evaluated.


A lisp is a type of speech impediment affecting the pronunciation of certain sounds. It commonly impacts how someone pronounces S, Z, or R. 

Lisping has no specific cause, though some factors may influence its development, including how we learn sounds, jaw alignment, pacifier use, and tongue tie. While most children outgrow their lisp after their toddler years, some may continue lisping as they age. 

Consult a speech-language pathologist if your child hasn’t lost their lisp by age 5. A speech therapist uses many methods to correct a lisp, including teaching correct tongue placement and practicing difficult words.

Last updated on February 9, 2024
6 Sources Cited
Last updated on February 9, 2024
All NewMouth content is medically reviewed and fact-checked by a licensed dentist or orthodontist to ensure the information is factual, current, and relevant.

We have strict sourcing guidelines and only cite from current scientific research, such as scholarly articles, dentistry textbooks, government agencies, and medical journals. This also includes information provided by the American Dental Association (ADA), the American Association of Orthodontics (AAO), and the American Academy of Pediatrics (AAP).
  1. Black, L., et al. “Communication Disorders and Use of Intervention Services Among Children Aged 3–17 Years: United States, 2012.” NCHS Data Brief, Centers for Disease Control and Prevention, 2015.
  2. Quick Statistics About Voice, Speech, Language.” National Institute on Deafness and Other Communication Disorders, U.S. Department of Health and Human Services, 2016. 
  3. Four to Five Years.” American Speech-Language-Hearing Association, 2022.
  4. Broomfield, J., et al. “Is speech and language therapy effective for children with primary speech and language impairment? Report of a randomized control trial.” International Journal of Language and Communication Disorders, National Library of Medicine, 2011.
  5. Ruscello, D. “Nonspeech oral motor treatment issues related to children with developmental speech sound disorders.” Language, Speech, and Hearing Services in Schools, National Library of Medicine, 2008.
  6. Allard, E., et al. “Listeners’ perceptions of speech and language disorders.” Journal of Communication Disorders, Elsevier, Inc., 2008.
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