Ultimate Guide to LISPs in Children & Adults

Key Takeaways

A lisp is a speech sound disorder where a person has difficulty pronouncing the /s/ and /z/ sounds, often substituting them with a “th” sound, and it can persist into adulthood if left untreated.
There are four main types of lisps, distinguished by tongue placement: the tongue pushing between the front teeth, touching the back of the teeth, letting air flow over the sides (a “slushy” sound), or contacting the palate.
Most children outgrow lisps by age 4–5; professional help is recommended if a lisp persists past this age, affects self-confidence, or makes communication unclear.
Speech therapy is the most effective way to treat a lisp, with a licensed therapist teaching correct tongue placement, providing personalized speech sound drills, and monitoring progress through regular sessions.
Early screening and intervention can reduce the risk of long-term lisping, supported by avoiding prolonged thumb sucking, encouraging correct tongue posture, and practicing early speech sounds through play.

Authored by: The DrSensory Editorial Team

Reviewed by: 🛡️ DrSensory Clinical Review Board

Last updated: June 2026

All medical content on this page has been reviewed and approved by licensed Speech Language Pathologists on the DrSensory Clinical Review Board. Our reviewers follow strict editorial standards and ensure alignment with current ASHA guidelines evidence-based practice, and speech therapy protocols.

What Is a Lisp?
Types of LISPs
Lisp vs. Other Common Speech Disorders Comparison
What Causes a Lisp?

14 min read

Signs and Symptoms
Diagnosis and When to Seek Help
How LISPs Are Treated
🗣️ Speech Therapy for LISPs
📍 Find a Lisp Specialist Near You
Preventing LISPs: Early Intervention
Success Story: Lily’s Lisp Therapy Journey (Case Study)
Frequently Asked Questions

What Is a Lisp? Types, Causes, Treatment & Therapists Near You | DrSensory

Find expert information, causes, treatment, and local speech therapists who specialize in LISPs near you.

What Is a Lisp?

A lisp is a speech sound disorder where a person has difficulty pronouncing the /s/ and /z/ sounds, often substituting them with a “th” sound. It commonly appears in childhood but can persist into adulthood if left untreated.

Types of LISPs

There are four main types of lisps:

Interdental Lisp

Tongue pushes between the front teeth when saying /s/ or /z/

Dentalized Lisp

Tongue touches the back of the teeth, distorting the sound

Lateral Lisp

Air flows over the sides of the tongue, creating a “slushy” sound

Palatal Lisp

Tongue contacts the soft or hard palate during speech

Lisp vs. Other Common Speech Disorders Comparison

Feature	Lisp	Apraxia of Speech	Phonological Disorder
Sound Affected	/s/, /z/	Multiple	Groupings of sounds
Type	Articulation	Motor Planning	Cognitive-linguistic
Can it Self-Correct?	Sometimes	Rarely	Occasionally
Best Treatment	Articulation Therapy	Motor-based Therapy	Phonological Intervention
Typical Age of Onset	2-4 years	18 months - 3 years	2-5 years

What Causes a Lisp?

Lisping can result from:
- Oral muscle weakness
- Tongue thrust
- Thumb sucking or prolonged pacifier use
- Hearing issues
- Developmental delays

Signs and Symptoms

Recognize a lisp early with these signs:

Substituting “s” and “z” with “th”
Difficulty being understood
Embarrassment or frustration while speaking
Unusual tongue placement

Diagnosis and When to Seek Help

Speech-language pathologists (SLPs) use observation, oral exams, and articulation assessments to diagnose lisps. Seek help if:

Lisp persists past age 4-5
It’s affecting self-confidence
Communication is unclear

Learn more about speech sound disorders

ASHA – American Speech-Language-Hearing Association: Lisping

NIH: Speech Sound Disorders in Children

How LISPs Are Treated

Treatment options may include:

Articulation therapy
Oral-motor exercises
Visual feedback tools (like mirrors or speech apps)
At-home practice strategies

🗣️ Speech Therapy for LISPs

Speech therapy is the most effective way to treat a lisp. A licensed speech therapist will:

Teach correct tongue placement
Provide personalized speech sound drills
Monitor progress with regular sessions

📍 Find a Lisp Specialist Near You

✅ Use DrSensory’s National Speech Therapist Database

Search by:

ZIP code
Insurance provider
Virtual or in-person services
Language or specialty

Start Your Search Now ➝

Preventing LISPs: Early Intervention

Early screening and intervention can reduce the risk of long-term lisping. Tips for prevention:

Avoid prolonged thumb sucking
Encourage correct tongue posture
Practice early speech sounds through play

Success Story: Lily’s Lisp Therapy Journey (Case Study)

At age 6, Lily had a noticeable lateral lisp that made her speech hard to understand. She began weekly sessions with a certified SLP using articulation drills and mirror work. After 5 months of consistent therapy and at-home practice, Lily’s /s/ and /z/ sounds improved dramatically. Today, she speaks with clarity and confidence!
— Macy T

Lisp Frequently Asked Questions (FAQ)

What age should a lisp go away?

Most children outgrow lisps by age 4–5. If a lisp continues beyond this age, professional help is recommended.

Can adults get rid of a lisp?

Yes! With regular speech therapy, many adults can improve or eliminate a lisp, even after years of speech difficulty.

Is a lisp a sign of a more serious condition?

Not usually. Most lisps are isolated articulation disorders, though persistent or severe cases should be evaluated for other speech or developmental conditions.

How long does speech therapy for a lisp take?

Duration varies based on age, type of lisp, and therapy consistency. On average, improvement is noticeable within a few months of weekly sessions.

Can I fix my child’s lisp at home?

Home practice can help, but guidance from a certified speech therapist ensures proper technique and faster progress.

Do lisps affect reading or learning?

Not directly, but children with speech sound disorders may also have challenges with phonemic awareness or confidence in classroom settings.

Can a child’s lisp come back after therapy?

Yes, especially if therapy is stopped early. Ongoing practice is key to long-term success.

Is it normal for a 5-year-old to have a lisp?

Mild lisps can be developmentally normal, but if it persists past 4.5–5 years, an evaluation is recommended.

Do bilingual children develop lisps more often?

Not necessarily. Lisping is not directly tied to being bilingual but may be more noticeable depending on language use.

Are LISPs covered by insurance?

Many insurance plans cover speech therapy with a referral. Use our tool to check coverage with local therapists.

What’s the difference between a frontal and lateral lisp?

Frontal lisp: Tongue sticks out front (like a “th” sound)
Lateral lisp: Air escapes over the sides of the tongue—creates a “wet” or slushy sound

This page provides general educational content and is not a substitute for professional medical advice. Always consult a licensed provider for diagnosis and treatment.

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