A LISP is a distorted production of the /s/ and /z/ sound which is the result of an incorrect motor pattern of tongue placement and movement. Lisps are some of the most common speech errors, research found that 23.3% of young adults had a lisp.
WHAT IS THE CORRECT PLACEMENT FOR THE /S/ AND /Z/ SOUNDS?
Correct placement for the /s/ and /z/ sounds are when the tongue is behind the top front teeth, barely touching the bumpy part (alveolar ridge). The tongue placement for the /s/ and /z/sounds are the same, except that the /z/ sound is voiced (touch your throat and feel vibration when producing the /z/ sound).
WHAT CAUSES A LISP?
We find that lisps can be caused by a variety of factors, including:
- Learning to mispronounce sounds and syllables.
- Problems with jaw stability, jaw sliding, or poor jaw alignment (malocclusion)
- A tongue tie which occurs when the tongue is attached to the bottom of the mouth and tongue movement is restricted.
- A tongue thrust which occurs when the tongue protrudes between a person’s teeth (a tongue thrust is a symptom that more is going on with a person’s oral function).
WHAT TYPES OF LISPS ARE THERE?
There are four types of lisps which are determined by the production of air flow. The first two are the most common in our practice.
INTERDENTAL:
With an interdental lisp, you’ll hear more of a /th/ sound than an /s/ or /z/ sound. The word “sink” would sound like “think,” and “z00” would sound like “thoo.”
LATERAL LISP:
In a lateral lisp, the tongue is close to the correct position. However, the sides of the tongue are not high enough in the mouth and are not touching the top back molars. When this happens, air escapes the sides of the tongue, and a “slush” or “wet” sound is produced. This type of lisp will not remediate on its own, nor will a child out grow out.
DENTALIZED LISP:
In the dentalized lisp, the tongue doesn’t protrude between the teeth like an interdental lisp, but it does push against the back of the front teeth. This produces a muffled or “airy” /s/ sound.
PALATAL LISP:
A palatal lisp is the least common. This is when the middle part of the tongue is raised to the hard or soft palate. While it is similar to the lateral lisp’s sound quality, the tongue’s body is touching the middle of the mouth, not behind the front teeth.
CAN SOMEONE OUTGROW A LISP?
The answer is yes and no. Per research, the lisp can disappear by age 4 ½ if it is genuinely developmental. Over the age of five, speech therapy is highly recommended. However, if the child is producing a “lateral lisp,” this is not considered developmental, and this type of lisp likely won’t resolve on its own. Furthermore, clinically speaking, a lateral lisp is likely to have a root cause related to an orofacial myofunctional disorder. For children who don’t learn to correct a lisp, it can persist into adulthood.
IS IT TOO LATE TO FIX A LISP?
No, it’s never too late to fix a lisp. We can help at any age, all that is required is motivation. Lisps can negatively affect people’s confidence and communication abilities in their careers or relationships. I have worked with both teen and adults who have successful remediated their lisps in a relatively short time.
If you or your child have concerns regarding a lisp, I recommend seeking an evaluation with a Speech Language Pathologist who is a Certified Orofacial Myologist (or received training in Orofacial Myology) to get to the root cause of that lisp