“My child has a lisp. Should we try speech therapy? Will it go away by itself?” These are common questions asked by caregivers.
In some countries and cultures, producing the ‘s’ and ‘z’ sounds with a lisp is not considered a speech error. Instead, it is viewed as a difference in pronunciation. As a result, some families may not feel the need to change a child’s lisp. However, in Canadian English, many families worry that a lisp may make their child harder to understand as they grow older.
The answer is not always straightforward. Several factors help determine whether a child would benefit from speech therapy. These include the child’s age, the type of lisp they have, how well they are understood by others (intelligibility), their speech motor skills, and their readiness for therapy. Some lisps are a normal part of speech development and often improve on their own. Others are less likely to resolve without support. Understanding these differences can help families decide when to seek guidance from a Speech-Language Pathologist (SLP).
Factor 1: Age
A child’s speech is often filled with mispronounced sounds and words. This stage is a normal part of speech development. Some children develop clear speech at an early age, while others need more time to develop adult-like pronunciation.
Speech development depends largely on a child’s speech motor skills. These skills include the strength, control, and coordination of the mouth, jaw, tongue, and lips. Messages from the brain must also travel efficiently to the muscles responsible for these movements.
The ‘s’ and ‘z’ sounds often develop between 3 and 4 years of age. During this time, children continue to gain strength, control, and coordination of their speech muscles, including the tongue. Many children outgrow a lisp on their own. However, the longer a child lisps, the more difficult it can become to break the habit. SLP therapy is often recommended if a child continues to lisp after 4 years old. Some children may benefit from therapy even earlier if they are ready to participate.
Factor 2: Type of Lisp
A child who places their tongue between their teeth when producing the s/z sounds has an interdental (frontal) lisp. This is the most common type of lisp. It can sometimes resolve on its own, often between 3 and 4 years of age.
A lateral lisp occurs when air escapes through the sides of the mouth while producing the s/z sounds. This creates a “slushy” sound. A lateral lisp may also affect other sounds, such as ‘sh’. This type of lisp is less common and usually does not resolve on its own. Children with a lateral lisp often benefit from SLP support as early as possible.
Factor 3: Intelligibility (How Well the Child Is Understood by Others)
One child may lisp on the occasional s/z sound during conversation and still have high intelligibility, meaning they are generally understood by others.
Another child may lisp on several sounds, including s/z, /t/, ‘sh’, and ‘ch’. This can reduce their intelligibility, meaning other people understand less of what they say. Every child’s lisp affects communication differently. Children with lower intelligibility are more likely to benefit from SLP therapy.
When Should You Seek Support?
Some children take longer than others to develop speech sounds. Some speech errors go away with time, while others can persist if they are not addressed. The longer an error continues, the more it becomes a habit, making it more difficult to change in the future. For this reason, providing support sooner rather than later is often recommended.
Some children simply need more time to develop their speech motor skills, including strength, control, and coordination. Others need more time to build therapy-readiness skills, such as attention. Once these skills develop, they may gain more benefit from SLP therapy.
An SLP consult or assessment can provide recommendations specific to your child. An SLP can also help determine whether speech therapy, home strategies to monitor speech development, or continued monitoring is the most appropriate next step.
