Lisping Health Article

Definition

A lisp is a functional speech disorder that involves the inability to correctly pronounce one or more sibilant consonant sounds, usually s or z.

Description

Lisping is a speech disorder characterized by the inability to correctly pronounce the sounds of s or z, known as the sibilant consonants. Usually th sounds are substituted for the sibilants. The word "lisp," for example, would be pronounced "lithp" by someone with this speech disorder.

Many children lisp at certain stages of speech development, especially when they lose their front primary teeth. Lisping is, therefore, sometimes called a developmental phonetic disorder. Frontal or interdental lisp is produced when the tongue protrudes through the front teeth when teeth are missing and is the most familiar type of lisp. Sibilant production may be interfered with in a number of other ways as well. These are all classified as lisping and include excessive pressure by the tongue against the teeth, the tongue held too far back along the midline of the palate, and a "substitute hiss" produced in the throat or larynx.

Sometimes children with functional speech disorders have problems making other sounds, such as sh, l, r, and ch. When a child cannot produce these sounds correctly, the condition is usually not considered a true lisp, but is a functional speech disorder.

Children can have a functional speech disorder as well as a developmental phonological disorder. The latter is not a matter of being able to physically make a specific sound but is a language disorder. These children have trouble organizing the sounds of speech in common patterns and may consistently replace one sound with another. For example, a child may say "wun" instead of "sun" or "doe" instead of "so."

There are four main types of lisps.

• Interdental lisp—occurs when the tongue protrudes between the front teeth and the s or z is pronounced like th.
• Dentalized lisp or dentalized production—occurs when the tongue pushes against the front teeth.
• Lateral lisp—sounds wet because the air flows around the tongue, which is in the normal position to produce the l sound.
• Palatal lisp—the middle of the tongue touches the soft palate, or roof of the mouth, when trying to produce the s sound.

Demographics

According to the National Institute on Deafness and Other Communication Disorders, about one in six people in the United States (42 million adults and children) has a communication disorder. Of them, 14 million have a speech, voice, or language disorder that is not linked to hearing loss. Functional speech disorders with no known cause, such as lisping, affect 10 percent of the population; 8–9 percent serious enough to require treatment. Nearly 5 percent of first graders have functional speech disorders, and 50–70 percent of all children with functional speech disorders struggle academically throughout elementary school and high school.

Causes and symptoms

As a functional speech disorder, lisping has no clear known cause. It is often referred to as a speech delay of unknown origin. Structural irregularities of the tongue, palate, or teeth (including abnormalities in the number or position of the teeth) may be implicated in lisping, but they generally are not the main causes. 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. It has been thought that some of these children may be imitating another child or an adult who lisps.

Lisping is also associated with immature development. Some children will adopt a lisp as a means of gaining attention. Other children will begin to lisp after they have experienced unusual stress or trauma. This behavior is part of a regression into a more secure period and can include other types of regressive behaviors such as bed wetting or wanting to sleep with the light on in the bedroom.

One theory of the cause of lisping is the result of tongue thrusting, a physiological behavior that causes the tongue to flatten and thrust forward during swallowing and speaking. It is suggested that thumb sucking, overuse of pacifiers, bottle feeding, and recurrent upper respiratory illnesses cause tongue thrusting. Thumbs (or fingers), artificial nipples, and pacifiers keep the tongue flat and do not allow the muscles of the tongue to develop in a normal fashion. When the child speaks, the tongue shoots forward, creating a lisp.

Frequent upper respiratory illnesses often stuff the nose, forcing these children to breathe through their mouths. The sounds that they make when they speak may be thick and garbled, and may encourage lisping. Closing the mouth and teeth to make s or z sounds cuts off the breath, so children compensate by trying to speak without closing their mouths completely. Thus, a lisp develops.