Speech Sound Production and Speech Intelligibility
What is Speech Sound Production?
Speech sound production refers to how children learn to make the sounds needed for talking. This includes the way they move their lips, tongue, jaw and voice to form sounds, words and sentences. Children develop different speech sounds at different ages, and many speech errors that affect intelligibility, are a typical part of learning to talk. However, when sound errors persist or make it hard for others to understand a child, a speech-language pathologist can help. When this process is disrupted, it can result in speech sound challenges. These types of sound errors are categorized into several types, each affecting different aspects of speech. The main types include:
Articulation and Oral-Motor Coordination
Involve errors in the production of individual sounds. For example, a child may have trouble pronouncing specific sounds correctly.
Phonological Awareness:
These are characterized by predictable patterns of errors that affect multiple sounds. Common errors include substituting one sound for another, such as using “w” for “r.”
Motor Planning or Neurological:
Errors arise from deficits in motor planning, sequencing, or executing as seen in childhood apraxia of speech or dysarthria. These conditions impact the coordination of the muscles needed for speech production.
Structural Differences
Errors caused by physical differences in the mouth, tongue or throat, such as orofacial anomalies or cleft palates that affect speech production.
Sensory or Perceptual Challenges:
Errors that result from hearing impairment, affecting how a child perceives sounds and consequently produces them.
Understanding the specific type of speech sound challenge is crucial for determining the most effective intervention and treatment plan.
Common Signs of Speech Sounds or Intelligibility Challenges
As a parent, you may have trouble understanding your child’s speech, or maybe a grandparent points out that they are hard to understand. Some things you might notice at home that may suggest your child could benefit from a speech sound evaluation, might include:
Distortions:
Sounds are altered in some way, like a lisp where the “s” sound is pronounced incorrectly.
Omissions:
Sounds are omitted from words, such as saying “tar” instead of “star.”
Substitutions:
One sound is replaced with another, like saying “pan” for “fan.”
Additions:
Extra sounds are added to words, like saying “buh-lue” instead of “blue.”
Syllable-level Errors:
Syllables within words are omitted, such as “efant” instead of “elephant.”
These errors can make it harder for others (even familiar listeners) to understand your child’s speech. These types of speech errors may relate to articulation delays, phonological disorders, childhood apraxia of speech, or oral-motor challenges, all of which can affect intelligibility. If you’re noticing frequent errors or reduced speech intelligibility, it may be time for a speech evaluation.
What is Speech Intelligibility?
Speech intelligibility refers to how easily a child’s speech is understood by others. It is one of the most important indicators of functional communication. Intelligibility affects how children interact with caregivers, teachers, and peers. Intelligibility directly impacts confidence, social-emotional development, and the ability to participate in everyday routines.
A child may have decreased intelligibility if you notice the below, and you may want to consider reaching out for a speech evaluation:
- You often ask them to repeat themselves
- People outside your household have difficulty understanding them
- They avoid talking in certain situations
- They become frustrated when trying to express themselves
- You notice sound errors that are not typical for their age
- Communication challenges are affecting school, friendships or their daily routines
Even when speech errors are typical for a child’s age, reduced intelligibility can affect daily life. Early support helps children build the clarity and confidence they need for successful communication.
Childhood Apraxia of Speech (CAS) and Treatment Approaches
Childhood Apraxia of Speech (CAS) is a motor speech disorder where children struggle to plan and coordinate the movements necessary for speech. Unlike typical speech sound disorders, CAS is characterized by inconsistent sound errors, difficulty with longer words, and challenges transitioning between sounds and syllables.
Treatment for CAS often involves specialized, evidence-based approaches, that can include:
- Kaufman Speech to Language Protocol (K-SLP) – A method that breaks down complex words into simpler parts, allowing children to build speech from basic word approximations toward full words.
- Pseudowords – Nonsense words that help children practice speech motor planning without relying on familiar words, promoting greater flexibility and accuracy in sound production.
- Dynamic Temporal and Tactile Cueing (DTTC) – A method for moderate to severe CAS that emphasizes repetition, slowed speech, and tactile/visual cues to improve sound accuracy.
- Prompts for Restructuring Oral Muscular Phonetic Targets (PROMPT) – A hands-on approach where the therapist physically guides the child’s oral muscles to help them form sounds correctly.
These techniques are used to help children with CAS improve their speech clarity and communication skills over time.
Expectations by Age for Speech Intelligibility
While every child develops at their own pace, research suggests a general pattern for how well children should be understood by unfamiliar listeners. The expected speech intelligibility for children by age is as follows:
2 Years Old
Child should be about 50% intelligible.
3 Years Old
Child should be about 75% intelligible.
4 Years Old
Child should be about 100% intelligible.
If your child’s intelligibility is noticeably lower than these ranges, or you have concerns, a speech evaluation can help identify what type of support may be beneficial.
How Hummingbird Helps Improve Intelligibility
Our pediatric speech-language pathologists use engaging, individualized, and evidence-informed strategies to help children produce sounds clearly and consistently. Therapy may include:
Targeted Sound Practice – Play-based activities that strengthen how children produce specific sounds and sound combinations.
Phonological Awareness Intervention – Helping children to understand sound patterns and rules that support clearer, more efficient speech.
Motor Speech Treatment – For children with motor planning challenges (such as childhood apraxia of speech), we focus on movement patterns, repetitions and cueing to build consistency.
Oral-Moto Coordination and Strengthening – Supporting the muscles that help children move their mouths efficiently for speech.
Parent Coaching and Home Practice – We partner closely with families so practice feels natural, supported, and realistic at home.
Our therapists meet each child where they are and create an individualized plan that focuses on progress, confidence, and communication.
Get the Right Support
At Hummingbird Pediatric Therapies, we are dedicated to helping children improve their speech sound production. Our team of experienced speech-language pathologists (SLPs) works closely with both parents and children to provide individualized treatment that helps your child achieve clearer, more effective communication.