Understanding Frontal and Lateral Lisps: A Parent-Friendly Guide

As a parent, you may have noticed that your child pronounces certain sounds differently than their peers. One common speech difference is a lisp. Lisps can affect how a child produces certain sounds, often making them sound unclear. Two primary types of lisps are frontal lisps and lateral lisps. Understanding these can help you determine whether speech therapy might be beneficial for your child.

What Is a Frontal Lisp?

A frontal lisp, also known as an interdental lisp, occurs when the tongue protrudes between the front teeth while producing "s" and "z" sounds. This results in a sound that resembles the "th" in "think" or "this." Frontal lisps are common in young children and can be a typical part of early speech development. Many children outgrow a frontal lisp by the age of 4. However, if it persists beyond this age, speech therapy may be recommended.

What Is a Lateral Lisp?

A lateral lisp occurs when air escapes over the sides of the tongue instead of flowing through the center of the mouth. This creates a slushy or distorted articulation of certain sounds, including "s," "z," "ch," "sh," "j," and "zh" (as in the middle sound of "treasure"). Unlike a frontal lisp, a lateral lisp is not considered a typical developmental pattern and often does not resolve on its own. Therefore, therapy is usually necessary to correct it.

Social and Communication Impact of a Lateral Lisp

Research indicates that a lateral lisp can draw adverse attention to the speaker and negatively impact social interactions and listener perception of the child. Children with noticeable speech differences may experience challenges in peer interactions, as listeners may perceive their speech as less intelligible or different from the norm. Addressing a lateral lisp through speech therapy can help improve not only speech clarity but also confidence in social communication.

What Causes a Lisp?

Lisps can be caused by various factors, including:

Habitual tongue placement
Orofacial muscle weakness or tone differences
Prolonged pacifier or thumb-sucking habits
Structural differences, such as dental alignment issues

Therapy Treatment Approaches

Speech therapy is the most effective treatment for both frontal and lateral lisps. The duration of therapy can range from a few months to a few years, depending on the individual’s age and severity of the lisp. Below are some commonly used therapy techniques:

Auditory Discrimination Training: Children first need to recognize the difference between correct and incorrect productions of the target sounds. This helps them become aware of their speech patterns.
Tongue Placement Awareness: For a frontal lisp, SLPs teach children to keep the tongue behind the teeth while producing "s" and "z." For a lateral lisp, they focus on directing airflow through the middle of the mouth.
Phonetic Placement Therapy: SLPs use verbal instructions, visual cues, and tactile feedback (such as placing a straw in front of the mouth to direct airflow) to help children position their tongue correctly.
Speech Drills and Practice: Once a child can produce target sounds correctly in isolation, they practice using them in syllables, words, sentences, and conversation.
Home Practice and Parental Involvement: Consistent practice at home is essential for progress. Parents can support their child by encouraging correct pronunciation and making speech practice fun.

When to Seek Therapy

If your child’s lisp persists beyond age 4 or significantly impacts their ability to be understood, a speech evaluation may be beneficial. A speech-language pathologist can assess their speech and develop a personalized treatment plan. Our team at Serenity Speech & Language Therapy offers free speech and language screenings to determine the need for further evaluation and/or therapy services. Get in touch with us today if you suspect your child may have a lisp.

References

American Speech-Language-Hearing Association. (n.d.). Speech sound disorders: Articulation and phonology. Retrieved from https://www.asha.org

Bauman-Waengler, J. (2020). Articulatory and phonological impairments: A clinical focus (6th ed.). Pearson.

Preston, J. L., Leece, M. C., & Storto, J. (2019). Evidence-based treatment approaches for persisting speech sound disorders. Language, Speech, and Hearing Services in Schools, 50(3), 451-461.

White, P., & McNutt, J. (1976). Listener perceptions of speakers with frontal and lateral lisps. Journal of Speech and Hearing Disorders, 41(4), 547-552. https://pubs.asha.org/doi/10.1044/jshd.4104.547

OpenAI. (2025). ChatGPT (March 2025 version) [Large language model]. Retrieved from https://openai.com