A Parent's Guide to Speech Sound Disorders

What Are Speech Sound Disorders?

Speech sound disorder is an umbrella term for disorders that make it difficult for children to produce speech sounds clearly.

It may be difficult to understand what these children are saying. Speech sound disorders can be broken up into three major categories: articulation disorders, motor speech disorders, and phonological disorders.

Treatment for speech sound disorders typically involves speech therapy and can help to improve the clarity and accuracy of speech.

What Is an Articulation Disorder?

Articulation disorders are traditionally what people think of when they think of being treated in speech therapy. Articulation refers to individual speech sounds and how they are pronounced. All children make some errors with speech sounds as they develop. Articulation disorders are when these errors continue beyond the time when a child normally outgrows them.

Sometimes this looks like individual sounds being substituted for other sounds (e.g., “dat” for “that” or “baw” for “ball”) or distorted. If a child has an articulation error with the “s” sound, a word like “superman” may sound like “thuperman”.

Articulation errors are motor-based issues– there is a breakdown in the movement of the articulators such as the tongue, lips, teeth, and other mouth muscles. Our goal is to help children accurately place and move these muscles to produce clear and precise speech sounds.

What Are Articulation Milestones?

Articulation milestones are quite a bit different than other developmental milestones because the range of when a child will accurately produce a sound can be wide. Children develop and fine-tune their articulation as they grow.

At one year old, the grocery store clerk may understand very little of what your child says. But as a three or four-year-old, you would expect that to change dramatically. In fact, by age 4, children should be 100% intelligible to the grocery store clerk (while there may still be some speech sound errors, in context, people should be able to understand your child).

The chart below can be used as a general rule of thumb for when children should say each sound in English.

English Speech Sound Development By Age

This represents the average age at which 90% of kids produce the English sound correctly across the world. (McLeod & Crowe, 2018)

What Is a Frontal Lisp?

A frontal lisp, also known as an interdental lisp (the tongue goes between the teeth), is a speech disorder in which a person substitutes an S or Z sound for a TH sound. For example, “thun” for “sun” or “thick” for “sick.”

Frontal lisps are very common in young children and can be typical through to age 4.5. You should consider an articulation evaluation for a frontal lisp around age 5 and before the baby teeth have fallen out. This is a great age to make quick work of the lisp.

What Is a Lateral Lisp?

A lateral lisp is a type of speech disorder that is characterized by the misarticulation of certain sounds, such as S, Z, SH, CH, ZH, J. 

Unlike with a frontal lisp where the tongue is directing air through the middle of the teeth, a lateral lisp is when a child directs airflow out the sides of the mouth. This can cause the child’s speech to sound slushy, “wet”, or distorted.

Lateral lisps can significantly impact speech clarity and are never a part of typical speech development.

We highly encourage you to seek out a speech evaluation as early as possible if you notice this type of lisp. The longer a child produces speech in this way, the more difficult it can be to correct later on.

What Are "R" Sound Errors?

R sound errors fall under articulation disorder. R is one of the trickiest sounds in English and is often one of the last to be mastered by children.

The R sound actually changes depending on where it sits in a word and what vowels it’s next to, making it more like 8 different speech sounds! The eight combinations are:

• The prevocalic R, such as in “robot”
• The RL, such as in “girl”
• The AR, such as in “car”
• The AIR, such as in “spare”
• The ER, such as in “summer”
• The EAR, such as in “near”
• The IRE, such as in “tire”
• The OR, such as in “snore”

The R sound is best treated around the age of 5, when complex instructions can be followed, and mispronunciations are less ingrained patterns of error.

What Are Orofacial Myofunctional Disorders?

Orofacial myofunctional disorders (OMDs) are a group of disorders that involve the orofacial muscles (mouth and face). These disorders affect the function and/or development of these muscles and can result in a variety of symptoms.

OMDs can contribute to articulation disorders. OMDs are abnormal movement patterns of the face and mouth that can impact or interfere with breathing, eating, and/or speech. 

Common symptoms of OMDs include problems with breathing, swallowing, speech, and chewing. Individuals with OMDs may also exhibit facial muscle imbalances or have difficulty maintaining proper oral posture. OMDs can occur in individuals of all ages, from infancy through adulthood.

Causes of OMDs include genetic factors, environmental factors, habits such as thumb-sucking, tongue-thrusting, and mouth-breathing, and neurological conditions.

Treatment for OMDs typically involves a combination of exercises to retrain the affected muscles and the use of orthodontic appliances or other devices to help maintain proper oral posture. This is not an area of expertise at Little Language Lab yet, we encourage you to learn more about OMDs at iaom.com.

What Are Phonological Disorders?

Phonological disorders are predictable, rule-based speech sound errors that affect more than one sound. 

When children are very young, their brains create rules to simplify speech sounds and make words easier to say. These rules are called phonological processes. These processes are often typical up until a certain age, at which point most children have corrected the process to the adult form. Sometimes, the rules to simplify speech sounds are atypical and not seen as part of normal child speech development.

“Daddy lets go to the park.” may sound like, “Daddy let’s doh to the part.”  (this process is called fronting where the sounds “k” and “g” become “t” and “d”)

“I see the sun in the sky.” may sound like, “I tee da tun in da ty.” for a phonological process like stopping (this is when The stopping phonological process is when a child produces a stop consonant /p, b, t, d, k, or g/ in place of a fricative /f, v, th, s, z, sh, ch/ or an affricate sound /j/.

When we learn language, our brains learn which sounds are important for meaning and which ones are not. For example, we know that the “t” sound in “tar” and “star” are the same even though they are slightly different. A child with phonological errors may have learned the wrong rules for speech sounds, such as confusing the “t” and “k” sounds so they may say “tootie” for “cookie” and “tate” for “cake”. This can lead to consistent or inconsistent errors when they speak or try to read and spell. Phonological therapy helps children learn the correct rules for speech sounds so they can communicate more effectively.

What Are Motor Speech Disorders?

In order to produce speech we have to coordinate a wide range of muscles including the tongue, lips, jaw, vocal folds, jaw, and respiratory system. In motor speech disorders there is a breakdown in the motor process.

Motor speech disorders are made up of two primary categories, apraxia and dysarthria. Both conditions can occur in children and adults, and people with motor speech disorders can have both apraxia and dysarthria at the same time.

Childhood Apraxia of Speech

Apraxia is a neurological motor speech impairment—where there is a breakdown in the transmission of messages from the brain to the articulators. There is no obvious weakness in these muscles, and the child may be able to move them when not trying to speak. With childhood apraxia of speech, children know what they want to say but there is a roadblock between the signal from the brain and the mouth. 

Dysarthria

With dysarthria, children have a lack of strength or control of the muscles. Some characteristics may include distorted vowels, slow and labored speech, nasal speech, and/or slurring words together. Dysarthria commonly occurs in children who have cerebral palsy, muscle diseases, or head injury.