Understanding Lisps: More Than Just an "S" Sound

Have you ever wondered why your sounds don’t come out right? or why sometimes your tongue slips forward or sounds a little fuzzy?

The underlying reason is due to tongue placement and airflow which can distort other sounds. This may result in a lisp-like pattern. 

Tongue Placement & Airflow Issues

Instead of directing air cleanly down the center of the tongue, the tongue may: 

  • protrude 

  • press against the teeth 

  • raise too high 

  • allow air to escape from the sides 

Lisps are one of the most common speech sound differences seen in both children and adults. While they’re often associated with difficulty producing the /s/ and /z/ sounds. Some other affected sound patterns are /sh/ and /zh/, /ch/ and /j/. 

When the tongue sits too forward in the mouth, the /t/ and /d/ and /n/ and /l/ sound production may be affected and when the tongue sits too far back, vowel sounds may be affected. 

For some individuals, a lisp is a mild speech quirk. For others, it can affect clarity, confidence, and participation in daily life. 

Are Lisps Treatable?

Yes. Lisps are highly treatable. With guidance and steady practice, many people make significant improvements—often faster than they expect. 

Lisps can be: 

  • Developmental (common in young children) 

  • Persistent (continuing past age 4–5) 

  • Present in adults who never received treatment or developed compensatory patterns 

A sudden-onset lisp in an adult, however, should be evaluated by a medical professional. 

The Four Main Types of Lisps

Although lisps vary in severity, four types are most observed. 

Interdental Lisp (Frontal Lisp)

The most common and easiest to identify.

Characteristics:

  • Tongue protrudes between the front teeth 

  • /s/ and /z/ sound like “th” (e.g., sun → thun) 

  • Often noticed early by parents or teachers 

Developmental

Sometimes typical for very young children but should be addressed if it persists beyond age 4–5. 

Dentalized Lisp

Similar to an interdental lisp, but the tongue does not protrude. 

Characteristics:

  • Tongue pushes against the back of the front teeth 

  • Airflow becomes muffled or blocked 

  • /s/ and /z/ sound dull or flat 

Treatment focus:

Retraining tongue placement just behind the teeth using visual and tactile cues. 

Lateral Lisp

Not developmentally typical at any age. 

Characteristics:

  • Air escapes over the sides of the tongue 

  • Speech sounds “slushy,” “wet,” or “spitty” 

  • Often compared to cartoon characters like Daffy Duck 

Why it’s harder to correct:

Airflow must be retrained to move forward rather than sideways, requiring targeted therapy. 

Palatal Lisp

Less common but important to identify early. 

Characteristics:

  • Tongue contacts the soft palate or roof of the mouth 

  • /s/ and /z/ sound dull or distorted 

Treatment focus:

Lowering the tongue body and establishing correct anterior placement. 

Why Do People Have a Lisp?

Lisps are motor-based speech sound disorders. They are not cognitive, psychological, or behavioral. 

Common contributing factors include:

Phonetic Motor Patterns

Most lisps are phonetic disorders—difficulty physically producing the sound due to incorrect placement or movement of the tongue, lips, or jaw. 

Physiological or Structural Factors

  • Variations in palate shape 

  • Tongue size or mobility differences 

  • Dental alignment or bite differences 

These factors may influence sound production but rarely prevent progress in therapy. 

Genetics

Family history of articulation challenges or structural differences in jaw/teeth positioning can increase the likelihood of a lisp. 

Tongue Thrust / Orofacial Myofunctional Disorders

A forward tongue pattern may overlap with interdental lisps. Causes may include: 

  • Prolonged pacifier or bottle use 

  • Thumb sucking 

  • Allergies or chronic mouth breathing 

  • Untreated tongue-tie 

Hearing Loss

Mild or fluctuating hearing loss—especially in high frequencies—can affect how children perceive and reproduce /s/ and /z/. 

How Lisps Affect Daily Life

Lisps can influence more than just speech clarity. 

Social & Emotional Impact

  • Teasing or bullying 

  • Embarrassment or self-consciousness 

  • Avoidance of speaking situations 

Communication Challenges

  • Difficulty being understood 

  • Frustration during conversations 

  • Reduced participation in school or work settings 

Self-Esteem

Persistent speech differences can affect confidence and willingness to engage socially or professionally. 

Words That Are Hard to Say With a Lisp

Because lisps primarily affect /s/ and /z/, words like these may be challenging: 

Sun

Snake

Sister

Spaceship

Pizza

Glasses

Busy

Music

Desserts

Fastest

Science

Frozen

Lisp 

How Speech Therapy Helps Correct a Lisp

Speech therapy is highly effective for both children and adults. Treatment focuses on motor learning, meaning the individual learns new, correct movement patterns for the tongue and airflow. 

Core therapy components include:

Articulation Therapy

  • Sound isolation 

  • Repetition and drill practice 

  • Blending sounds into syllables, words, and sentences 

  • Gradual progression toward conversational speech 

Phonetic Placement Therapy

  • Mirror work 

  • Tactile cues 

  • Visual models 

  • Step-by-step placement training 

Auditory Discrimination

  • Hearing the difference between correct and incorrect productions 

  • Sound identification and matching 

  • Listening games 

Oral Motor or Myofunctional Exercises

Used when tongue thrust or muscle patterns contribute to the lisp: 

  • Straw sucking 

  • Tongue placement drills 

  • Lip and tongue strengthening 

  • Controlled airflow exercises 

At-Home Activities to Support Lisp Correction

Home practice reinforces therapy and accelerates progress. 

Try incorporating: 

  • “Snake sound” /s/ practice 

  • Mirror work for visual feedback 

  • Straw airflow activities 

  • Books with frequent /s/ and /z/ sounds 

  • Gentle reminders to keep the tongue behind the teeth 

  • Listening games to identify correct vs. incorrect productions 

Short, frequent practice sessions are more effective than long, infrequent ones. 

Can a Lisp Be Corrected?

Yes. Most lisps can be significantly improved or fully corrected with structured speech therapy. Early intervention leads to faster progress, but adults benefit just as much from targeted treatment. 

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