A lisp is a speech sound disorder that involves difficulty pronouncing certain sounds correctly. The most common types of lisps are characterised by difficulties with the production of the "s" and "z" sounds.
Interdental Lisp: With an interdental lisp, the tongue protrudes between the front teeth during the production of "s" and "z" sounds, resulting in a sound similar to the English "th."
Lateral Lisp: In a lateral lisp, air escapes over the sides of the tongue, rather than over the centre during the production of "s" and "z" sounds. This can lead to a wet or slushy sound that is different from the intended pronunciation.
Palatal Lisp: With a palatalised lisp, the "s" and "z" sounds are pronounced with the tongue rising up towards the hard palate. This can lead to a sound that is more like a whistling "sh".
Dentalised Lisp: In a dentalised lisp, the "s" and "z" sounds are produced with the tongue against or between the front teeth, creating a sound that is different from the standard pronunciation.
Lisps are not limited to these categories, and a person with a lisp can present with a combination of features from different types of lisps.
Some children may naturally outgrow lisps as they develop their speech and language skills, while others may require speech therapy to address and correct the issue.