Lisping: All you need to know

Lisping: All you need to know

Lisping: All you need to know

A lisp is a functional speech disorder, which makes learning a specific speech sound, or a few specific speech sounds difficult.  How many of you know the cartoon character “Sylvester” he is a cat with a lisp. Yes, you heard that right, so if you want to know how lisping sounds like, check out his cartoon.lisping sounds

Many of us believe that lisping is primarily associated with incorrect production of sibilants i.e. /s/ and /z/ making it sound distorted. While this is true to a certain extent, in reality, the complications can be even worse.   Medical professionals and speech-language pathologists have identified four types of lisp disorders viz :

  • Frontal Lisp
  • Dental Lisp
  • Palatal Lisp
  • Lateral Lisp

Let’s now look into each one of them in detail:

  1. Frontal (Interdental) Lisp

Primarily, speech, or any sound for that matter, is produced with the combination of the correct placement of the tongue in the mouth and the expulsion of air. With a frontal lisp, the tip of the tongue protrudes between the front teeth, that is, it obstructs the airflow. Consequently, the “s” and the “z” sound in words tend to be vocalized as “th” sounds. For example, words like “bass” and “slate” may be pronounced as “bath” and “thate”. This is the most commonly found type of lisp.

  1. Dental Lisp

This is a lot like a frontal lisp. The main difference is that in a frontal lisp, the individual protrudes their tongue between the front teeth, while with a dental lisp, the individual pushes their tongue against the front teeth. Just like a frontal lisp, a dental lisp may be seen in very young children as they are just learning to form coherent sentences, but it usually goes away by the age of four.

  1. Palatal Lisp

As the name suggests, this lisp has an association with the soft palate, that is, the roof of the mouth. Whenever an individual roll their tongue too far back and touches it against the roof of the mouth, they tend to develop palatal lisping.

Unlike interdental and dentalised lisps, palatal lisps are not characteristic of normal development.

  1. Lateral Lisp

A lateral lisp occurs when the airstream for the ‘s’ sound, which is normally directed through the center of the mouth, is thrust down laterally around the sides of the tongue.

So instead of a hissing, the sound is more of a wet and slushy noise where the sound swirls out of the sides of the mouth rather than directly through the center. Individuals with a lateral lisp often sound as if they have too much saliva in their mouth

Dental lisps and frontal lisps are a part of normal speech development but the lateral and palatal lisps are not a part of normal speech development and hence it will need immediate remedial support.

Causes of Lisp:

As a functional speech disorder, lisping has no clear known cause. It is often referred to as a speech delay of unknown origin. But to mention a few of the known causes are as follows:

  • Structural irregularities of the tongue, palate, or teeth (including abnormalities in the number or position of the teeth).
  • Mild hearing loss involving high frequencies may also impair a child’s ability to hear language correctly and be able to repeat phonetic sounds.
  • In some cases, a child with no physical abnormality will develop a lisp. They might be imitating someone who has a lisp. Some children will adopt a lisp as a means of gaining attention.
  • Immature development.
  • Lisping developing after some psychological trauma
  • Tongue thrust.
  • Frequent upper respiratory illnesses often stuff the nose, forcing these children to breathe through their mouths. Closing the mouth and teeth to make or sounds cuts off the breath, so children compensate by trying to speak without closing their mouths completely. Thus, a lisp develops.


Lisping may not present by itself, there might be associated conditions too. The primary condition among them is “tongue thrust”. Tongue thrust, or “reverse swallow”, is an orofacial muscular imbalance where the tongue comes forward exaggeratedly between the teeth. This can happen while speaking, swallowing, or even when the tongue is at rest.

Because tongue thrust can cause significant dental issues in the future, it’s important to determine whether the lisp is actually the result of tongue thrust or not. Most children with tongue thrust issues outgrow them by age six but remember early intervention is always better for a better prognosis.

teaching speech therapyWhen to consult an SLP?

The interdental lisp and the dentalized lisp are common in normal speech development. Lisping can be common in small children as well as those who have lost their front teeth. However, if your child’s lisp goes beyond their early elementary school years or starts to interfere with overall communication, it’s important to see a speech therapist. The evaluation will determine if there is a physiological basis for the lisp and identify the type of lisp. Lateral and palatal lisps are not found in typical speech development and should be evaluated by a speech-language pathologist. If untreated, lisping can persist into adulthood.

For some children, everything they say seems to be interdental. In these cases, there may be an obstruction of the nose because of infection, allergy, enlarged adenoids, or other facial problems. Excessive interdental speech can also be related to mouth breathing and sucking habits. These children should be seen by a physician to treat the health problems and then referred to a speech-language pathologist to correct the lisp.

Read a detailed blog Tips for improving speech clarity in kids

Treatment for Lisping:

Treatment for Lisping

Articulation therapy proves successful for a lisp. A speech-language pathologist finds out whether the child can hear proper speech sounds, and proceeds to read a list of words with specific sounds that the child is having trouble articulating. Lists of contrast words are also read so that the child can hear the minimal differences in different sounds in a word. Therapy then moves to working on the position in the word where the sound occurs; that is, in the beginning, in the middle, or at the end. Specific word exercises follow, beginning with single sounds, then syllables, and moving on to words, phrases, and sentences. Finally, the child participates in controlled conversations.

      How can parents reduce the risk of a lisp?

  • Prevent tongue thrusting by restricting pacifier use or choosing to breastfeed their babies.
  • Speak clearly in complete sentences around their children and not use baby talk.
  • Treat allergies and respiratory illnesses immediately to keep the nose open and breathing free.
  • Monitor the child’s hearing ability.
  • Practice drinking from a straw, this will help the oral musculature to improve the intelligibility of speech

Even though early intervention is critical for a better prognosis, it’s never too late to see a speech therapist as an adult.  With dedicated practice, a lisp can be corrected. Most lisps are developmental and resolve themselves in children by the time they are about five to eight years old. Speech therapy is recommended if it lasts longer. The outcome of speech therapy is usually quite good.

Depending on the underlying cause, treatment can take a bit longer, so consistency is key.

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