A lisp is one of the most common articulation errors targeted in speech-language therapy. It is a sound substitution or distortion in which the “s” and “z” sounds are produced inefficiently.

If your child has a lisp, it can impact how well they are understood by others. Treatment of speech sound errors targets tongue placement, airflow and differentiation of voicing. There are two different types of lisps:

Interdental Lisp

An interdental lisp is the one that most are familiar with, in which an individual uses a “th” in place of the “s” or “z” sound. For example, someone with an interdental lisp would say “thaw” rather than saw or “beeth” instead of bees. 

 For this type of lisp, the tongue is placed between the teeth. Treatment typically focuses on correct tongue placement behind the teeth. In young children, this type of lisp is considered developmentally appropriate and expected until the age of 5.

 Lateral Lisp

A lateral lisp is characterized by a more “slushy” sound during “s” and “z” production. During typical production of the “s” and “z” sounds, air moves through the middle of the mouth and escapes out of the mouth through the front teeth.  When air instead escapes out the sides of a person’s mouth, distortion occurs.

 A lateral lisp is never developmentally appropriate, and treatment can improve the movement of air flow for clear sound production.

Children with lisps may also have difficulty producing the “ch” (chip), “sh” (ship), “j” (jungle) and “jz” (treasure) sounds.

If you have questions about your child’s speech, schedule an evaluation with a certified speech-language pathologist (SLP). Speech-language therapy is individualized, meaning that an SLP will work with you to develop therapy targets that are unique for your child, depending on their individual needs.