Abby Barnes, M.S., CCC-SLP
If your child is having trouble with their /s/ or /z/ sounds, they may have a lisp. For some kids, a lisp is part of their speech development and resolves on its own. Other children may need speech therapy to correct a lisp.
Key takeaways
A lisp is an incorrect production of the /s/ or /z/ speech sound.
Some kids will outgrow a lisp, usually by age 8. Other children will need speech therapy to fix a lisp.
Interdental (or frontal) and dentalized lisps are the most common types of lisps in children.
A lisp is not typically associated with autism, but it may be linked to a tongue tie or tongue thrust.
Speech therapy for children with lisps is individualized and play-based, targeting tongue placement and frequent practice of the correct sounds.
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Find a speech therapistWhat causes a lisp in a child?
A lisp is an incorrect production of the /s/ and /z/ speech sounds. A lisp is caused when a child learns an incorrect motor pattern of tongue positioning and movement for these two sounds.
Lisps can be common in children. Marissa Silva, M.S., CCC-SLP, a speech therapist at Expressable, has worked with many children who have problems with the /s/ and /z/ sounds. She explains, “When a child speaks with a lisp, they’re placing their tongue in a way that obstructs the airflow needed to make the /s/ and /z/ sounds. That distorted airflow creates the lisping sound.”
The reason for this incorrect tongue position isn’t always clear. Lisps can be caused by a variety of factors, including:
Learning to produce the /s/ and /z/ sounds incorrectly
A jaw misalignment, or problems with a child’s jaw alignment
A tongue tie, which occurs when the tongue is attached to the bottom of the mouth and its movement is limited; this may lead to a lateral lisp
A tongue thrust, in which the tongue protrudes forward; this can also impact feeding and swallowing
At what age do children normally develop correct /s/ and /z/ sounds?
Some children may say /s/ and /z/ sounds correctly right away. Others may have trouble learning these sounds. They are some of the more challenging sounds in the English language!
Mastery of the /s/ and /z/ speech sounds can happen anywhere between 3 and 8 years old.
If a child is 8 years old and still having trouble with these sounds, this is considered an articulation or phonological delay.
Keep in mind, however, that it isn’t ideal to start working on these sounds this late. Get ahead and start practicing them by age 5 or 6 if your child is having trouble. It’s a good idea to see a speech therapist at this age for an evaluation.
Types of lisps common in children vs. adults
There are four different types of lisps: interdental, dentalized, lateral, and palatal. An adult or child could have any of these lisps. But the most common lisps in children (as well as in adults) are the interdental and dentalized lisps.
Something to remember: Interdental and dentalized lisps can be part of normal speech development in kids. However, lateral and palatal lisps do not happen as part of a child’s natural development. It can sometimes be hard to tell the difference, which is why a speech evaluation is so helpful if you notice your child struggling with these sounds.
Here’s a closer look at the four types of lisps:
Interdental lisp
An interdental lisp may also be called a frontal lisp. With this lisp, a [th] sound is produced instead of an /s/ or /z/ sound. So a word like “soon” may be pronounced as “thoon,” and a word like “zebra” may be pronounced as “thebra.”
“These are the lisps I see most often in treatment with children,” Silva says.
An interdental lisp is developmentally normal until around age 4½. Most children naturally outgrow it by then.
Dentalized lisp
A dentalized lisp is similar to an interdental lisp. The tongue pushes against the back of the front teeth, directing airflow forward. This can cause a muffled sound when speaking. It sounds similar to an interdental lisp, but with less airflow.
Lateral lisp
Lateral lisps are not very common. A lateral lisp makes a distinguishable sound once you know what to listen for.
In this type of lisp, the tongue is close to the correct positioning. However, the sides of the tongue are lowered some, which can cause air to escape from either side of the mouth. All of this extra air causes the speaker to sound “slushy,” “wet,” or “spitty.”
Palatal lisp
A palatal lisp occurs when the tongue raises up and touches the roof of the mouth, also called the soft palate. While this type of lisp is not as common, it can make it hard to pronounce the /s/ and /z/ sounds.
Is a lisp associated with autism or other conditions?
A lisp is a sign of a speech sound disorder. Lisps are not linked to autism. An autistic person can have a lisp, but the lisp is not the result of autism.
“These are two different types of diagnoses,” says Silva. “A lisp is a speech sound disorder. Autism is a neurodevelopmental condition with differences in social communication.”
As mentioned earlier, a tongue tie or tongue thrust could potentially be involved with a lisp, but this is not always the case.
Learn the signs of autism, how it can affect communication, and how speech therapy for autism can help children, teens, and adults.
When should I be concerned about my child's lisp?
Silva recommends that if your child is age 6 or older and not showing improvement with a lisp, it’s time to start thinking about ways to support them.
For 6- and 7-year-olds, you can try working on their speech at home. You can help them notice when they say the sound incorrectly, practice correct tongue placement, and even practice simple words that start with /s/ or /z/ sounds, if they seem ready for that.
If you’re noticing other speech errors in your 6-year-old, contact a speech therapist to see about an evaluation. While kids don’t have to be pronouncing /s/ and /z/ perfectly at age 6, their speech overall should be improving. There may also be other sounds they need support with.
If a lisp is still hanging around at 8 years old, it’s definitely time to talk to a speech therapist. They can assess your child to see what type of lisp is present, as well as goals to be targeted in speech therapy.
Trouble with the /s/ sound, or a lisp, can make your child’s speech more difficult to understand. Here's what you need to know.
What does speech therapy for a child’s lisp look like?
Lisp speech therapy for children should be fun, engaging, and play-based. Your speech therapist will first identify the right goals to work on. Maybe the child needs to learn to identify a correct /s/ or /z/ from an incorrect one. This can be challenging for many children. From there, they may practice tongue placement, and practice the sound on its own or in words. Speech therapy will be tailored to the child’s exact needs and build in complexity over time.
Kids can play games, make crafts, or play with toys while they practice the /s/ or /z/ sound. Maybe they work on hidden pictures to find images with the target sounds. They might say target words during each step of a craft, or ask for pieces of a puzzle by saying a target word each time.
Speech therapists keep track of how well kids are making progress and what type and amount of help they need. Over time, they will decrease the amount of help they give the child so they can learn to make these sounds on their own.
Practicing at home is one of the best things families can do in order to speed up progress. Your speech therapist will explain how you can work on goals at home. Following through with practice helps kids improve their lisp—and possibly graduate from speech therapy more quickly!
Do you think your child might have a lisp?
If you think your child has a lisp and their speech isn’t improving, or they’re age 8 or older, let our team of expert speech therapists help you. We offer flexible online sessions at times that work for you, so you can attend speech therapy alongside your child and learn how to help them at home. Get matched with a speech therapist and schedule an evaluation today!
Frequently asked questions (FAQs)
Lisps are typically not permanent. Some kids with lisps will learn how to say /s/ and /z/ sounds on their own. Others may need help from a speech therapist. Speech therapy is effective for fixing a lisp, and most people can correct a lisp over time. However, for people who have had a lisp for many years, or who have structural differences in their mouth or with their tongue movement, a lisp may not fully resolve. It’s important to talk with a speech therapist about your or your child’s situation.
You should start seeing gradual improvement in your child’s speech by age 6. A lisp should be fully gone by age 8.
If a child still has a lisp at age 8, it’s important to schedule a speech evaluation. But keep in mind that you shouldn’t wait until your child turns 8 to start speech therapy. If they’re at least 6 years old and not showing improvement with /s/ and /z/ sounds, reach out to a speech therapist to figure out next steps.
Correcting a lisp requires practicing the correct tongue placement in order to learn how to say accurate /s/ and /z/ sounds. After a child can make these sounds, they can start practicing them in words. You can practice at home with your child, but in many cases speech therapy will be necessary. Lisps can be tricky, and it’s important to get the right support early on so you don’t unintentionally worsen the lisp or cause new speech problems.
No 3-year-old will speak 100% perfectly. It’s normal to hear mispronunciations. However, you should be able to understand most of what your child is saying. If your child is difficult to understand (by you, or by others), or they mispronounce a lot of words, consider having a speech evaluation. A licensed speech therapist can determine how your child is progressing and whether they need therapy. Early intervention is best!
How Expressable Can Help
Concerned your child isn't reaching age-expected milestones? Looking for communication support from a professional? Expressable is a national online speech and occupational therapy practice serving children and adults. We treat all major areas of communication, feeding, and developmental skills, offer flexible hours including evenings and weekends, and accept most major health insurance plans. We’re proud to have earned more than 4,500 5-star reviews from our clients (4.83/5 average).
Our therapy model is centered on parent and caregiver involvement. Research proves that empowering caregivers to participate in their loved one’s therapy leads to better outcomes. That’s why we combine live, 1-on-1 speech and occupational therapy with personalized education and home practice activities for faster progress.
