What is a Lisp?

What is a Lisp?

A lisp is a type of articulation disorder. It is characterised by a person’s inability to correctly pronounce /s/ and /z/ sounds, because of the incorrect tongue placement. The sound might be mispronounced as the /th/ sound or might be a bit distorted.

Lisps usually develop during childhood and often go away on their own. But in some cases it might persist into adulthood and require some form of treatment.

Types of Lisps

There are four types of lisps:

  • Frontal lisp: This lisp occurs when the tongue is pushed too forward while making the /s/ or /z/ sound. This ends up making a "th" sound.
  • Lateral lisp: This lisp occurs when extra air slides over the tongue when making /s/ and /z/ sounds, making it sound like there is excess saliva.
  • Palatal lisp: This lisp occurs when the tongue touches the roof of the mouth when making /s/ and /z/ sounds
  • Dental lisp: This lisp sounds like a frontal lisp. The only difference is that instead of pushing the tongue through the teeth, the tongue  is pressing against the upper teeth.
What Causes a Lisp?

A lisp is a common type of speech impediment. There are several potential causes of lisping:

  • Learning to pronounce sounds incorrectly
  • Problems with jaw alignment
  • Tongue tie: where the tongue is attached to the bottom of the mouth which limits its movement
  • Tongue thrust: when the tongue protrudes out the front teeth

Some of these issues might be apparent from birth while others might develop as a child learns to speak. Some people think that using a pacifier may contribute to lisps. However, while true in some cases, pacifier usage is not a factor in every child with a lisp.


Speech therapists work with people who have lisps in order to make articulation of the /s/ and /z/ sounds clearer.  An SLT helps children recognise what their lisp sounds like and teaches them the correct tongue placement to make the sound. If your child's lisp is from a physical condition your SLT might refer you to a surgeon or dental specialist.

How can I support my child?

You can help your child with a lisp in the following ways:

  • Always model correct pronunciation of the /s/ and /z/ in your own speech.
  • Bring yourself to their eye-level while producing the sound so that they can see what your mouth is doing when you make the sound.
  • If you notice your child continues to have a lisp at age 4 or you are concerned about their overall speech development, seek a consultation with a Speech and Language Therapist for advice.

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