Speech Sounds
What are speech sounds?
Speech sounds refer to the way that we use our tongue, lips and teeth to make sounds in words.
This is also known as ‘articulation’ or ‘pronunciation’.
Speech pathologists may also refer to the term ‘intelligibility’, which indicates how easy it is to understand a person’s speech (this has nothing to do with intelligence).
How do speech sounds develop?
Children start learning about speech sounds as soon as they are born. They quickly begin to recognise which sounds belong to the language of their parents and caregivers, and pick up on how changes in speech sounds can alter the meaning of a word. For example, for an English-speaking person, ‘led’ and ‘red’ are distinct words which have different meanings, whereas in other languages, these two words sound the same.
This is due to a process called ‘auditory discrimination’ and means that people learn to pay more attention to sound differences that are important for their own language.
The following information is intended to provide a guideline only. Many different factors influence whether a child may need therapy, and age is only one part of the picture. Other important considerations include the level of frustration a child may be experiencing, whether others are reacting negatively to their speech, whether their speech is very hard to understand, whether there has been little improvement over time, or if there are signs of broader difficulties in communication or other areas of development. These kinds of factors help us build a more complete picture of a child’s needs.
What is typical?
Each child develops speech sounds at their own pace but it can be useful to understand what features are typical at certain ages.
Birth - 12 months
When babies are young, they initially use open vowel sounds like ‘oooo’ and ‘ahhhhh’. By 7-9 months, babies are beginning to make consonant sounds like ‘ma’ or ‘ba’. These don’t sound like real words yet but are important for babies to practise making different types of sounds with their mouths.
At around 12 months, many children say their first proper ‘word’ by using a consonant vowel combination and referencing a particular ‘thing’ (like Mum, Dad or the family pet!). These words often include lip sounds like ‘m’, ‘p’ and ‘b’.
12 - 24 months
Between 12 – 24 months, children start to expand the number of consonants they are using (especially as they increase the number of words that they can say). Words may not be clear and you may see common error patterns when children are attempting to say particular sounds.
2 - 3 years
As children enter toddlerhood, their speech typically becomes clearer but may still be difficult for unfamiliar listeners to understand.
Typical error patterns include:
- Fronting– this is when sounds that are usually made at the back of the mouth (‘k’ and ‘g’) are replaced with front sounds (‘t’ and ‘d’). For example, a child may say ‘tar’ instead of ‘car’.
- Cluster reduction– this is when one of the sounds in a consonant cluster is left off. For example, a child may say ‘nake’ instead of ‘snake’.
- Gliding– This is when a ‘w’ or ‘y’ sound is used instead of ‘l’ or ‘r’. For example, a child may say ‘wed’ instead of ‘red’.
These errors are called ‘phonological processes’ and occur as the child is trying to organise a ‘map’ in their brain of how sounds are used in words.
3 - 4 years
At this age, children typically become much easier to understand.
By 4 years of age, many error patterns (phonological processes) have started to resolve. Children are usually able to use ‘k’ and ‘g’ in words and say both sounds in words that have 2 consonants together (such as ‘snake’). By this age, most children are also able to use ‘sh’, ‘s’, and ‘f’, and include all syllables in longer words, such as ‘elephant’.
Children may still be developing the ‘l’, ‘r’ and ‘th’ sounds.
4 - 5 years
As children start kindergarten or school, their speech is typically understandable to most people.
Children may still be developing the ‘r’ and ‘th’ sounds.
6 - 7 years
At this stage, children can typically say all speech sounds clearly. Some children may be consolidating the final speech sound to develop- ‘th’.
What is a speech delay?
Speech sound errors are quite common for young children as they navigate language learning and develop new sounds.
Many speech sound errors will start to disappear naturally between the ages of 3 and 5, but sometimes, these errors may persist for longer than expected.
When speech sound errors do not disappear by the age typically expected, it is referred to as a phonological delay or ‘speech delay’ and may require speech therapy intervention to resolve.
Some children substitute sounds that are unexpected at any age. These are called atypical errors. Atypical errors are unlikely to resolve naturally and will likely require speech pathology intervention.
Examples of atypical errors:
Backing
This is the opposite of ‘fronting’ and occurs when sounds that are usually made at the front of the mouth (‘t’ and ‘d’) are replaced with back sounds (‘k’ and ‘g’). For example, a child may say ‘koo’ instead of ‘two’. This is not typical at any age.
Vowel Errors
Some children may have vowel errors, for example ‘bord’ instead of ‘bird’. This is not typical at any age.
What are speech sound disorders?
A speech sound disorder affects the way that sounds are produced, and can include a child with a speech delay. A person with a speech sound disorder usually knows what they want to say, but has trouble using the right sounds to say words clearly and accurately.
This is different from an expressive language disorder, which affects the way that the brain finds words, and puts sentences together.
Types of speech sound disorders include:
Articulation Disorder
Articulation refers to the way that the tongue, lips and teeth (‘articulators’) work together to make particular sounds in the mouth. Sometimes, these articulators might be in a slightly different position to what’s expected, which can cause a change in the way the sound is made or affect the sound quality. Articulation errors can interfere with how ‘clear’ the speech sounds.
One of the most common articulation errors is called a ‘lisp’. Types of lisps include:
- Inter-Dental Lisp
An interdental lisp is when a person produces the “s” and “z” sounds with their tongue protruding between their front teeth.
This results in a “th” or “thick” sound. This is typical for children under 4-5 years of age but may be considered a delayed speech sound error if it continues into primary school years.
- Lateral Lisp
A lateral lisp is when the “s” and “z” sounds are pronounced with air flowing over the sides of the tongue, instead of over the centre of the tongue.
This results in a distorted or slushy sound, and can make speech difficult to understand. Lateral lisps are unlikely to resolve naturally and generally require speech pathology intervention to change the production of the sound.
- Palatal Lisp
A palatal lisp is when the blade of the tongue (behind the tongue tip) makes contact with the hard palate on the roof of the mouth, rather than using the tongue tip behind the teeth to make the “s” and “z” sounds. Palatal lisps usually require speech pathology intervention to change the production of the sound.
Phonological Disorder
Phonological disorders affect a person’s ability to correctly organise and use speech sounds in words. In many cases, the person is able to say the sound on its own, but they have trouble using the sound correctly in words.
Phonological speech errors often follow patterns, such as substituting one sound for another. For example, a young child might say ‘wed’ instead of ‘red’ or ‘tar’ instead of ‘car’.
Phonological sound substitutions (sometimes called ‘phonological processes’) are common and typical components of speech development in children. Often, different errors will resolve by a particular age, without the need for speech pathology input.
However, there are certain phonological errors that are not typical at any age, and others that persist beyond the age expected for most children. In these cases, the person would likely need speech therapy to resolve these errors.
Childhood Apraxia of Speech (CAS)
To talk, messages from the brain tell muscles around the mouth and throat to move. In CAS, those same motor command signals don’t get through correctly, and the person might have difficulty producing the sound or word that they want to say.
CAS affects the ability to plan and coordinate the movements necessary for speech, and primarily stems from difficulties in motor planning and execution.
Therapy programs for CAS include:
- Nuffield Dyspraxia Programme
Nuffield Dyspraxia Programme is a well-regarded and evidence-based therapy program developed in the UK to help children with apraxia of speech. The program focuses on building skills in a step-by-step manner related to motor articulation and coordination required for speech. It starts with single sounds and progresses to sentences and everyday conversations.
- Rapid Syllable Transition Treatment (ReST)
Rapid Syllable Transition Training (ReST) is an evidence-based therapy program designed to support children with apraxia of speech and other motor speech disorders. This approach focuses on helping children improve three key challenges often associated with apraxia of speech: inconsistent speech errors, difficulty transitioning between sounds, and inappropriate prosody (speech rhythm and intonation).
ReST uses made-up (nonsense) words to avoid reinforcing any existing errors in the child’s speech. By working with these words, the therapy helps children develop new, accurate speech patterns. Based on motor learning principles, ReST has been shown to benefit children of various ages by targeting these core areas. The therapy simplifies its focus into three main concepts—”sounds, beats, and smoothness”—to help children combine sounds more effectively and naturally.
- Dynamic Temporal and Tactile Cuing (DTTC)
Dynamic Temporal and Tactile Cueing (DTTC) is a therapy designed for children with severe childhood apraxia of speech. It focuses on improving the brain’s ability to plan and coordinate the movements needed for clear speech. While highly effective, DTTC is intended as a short-term, intensive approach rather than a long-term therapy.
In DTTC, children practise specific words through repeated trials, with guidance from their clinician. This guidance includes tailored auditory, visual, and tactile cues to target the child’s specific difficulties. By using these personalised cues, the therapy helps children improve their motor programming—the way their brain sends signals to produce speech sounds.
- Integrated Phonological Awareness (IPA)
The Integrated Phonological Awareness (IPA) approach combines the development of phonological awareness, speech production, and letter-sound recognition to support children with speech and language difficulties.
The process begins with an assessment to understand the child’s current phonological awareness skills and establish a baseline for measuring progress. Intervention is then carefully planned, using activities such as nursery rhymes, exposure to alphabet knowledge, and other engaging strategies to build the child’s skills.
Dysarthria
Dysarthria is typically caused by muscle weakness or paralysis of the speech muscles due to conditions such as stroke, brain injury, or neurological diseases. Dysarthria often leads to slurred speech, reduced volume, and changes in pitch. Treatment often focuses on strengthening or compensatory techniques to improve muscle control.
How do tongue ties impact speech sound production?
A tongue tie (also known as ‘ankyloglossia’) is a piece of connective tissue that tethers the tongue to the floor of the mouth.
There is no universally agreed-upon assessment or scoring system for diagnosing a tongue tie, which makes it very difficult to work out exactly how common they are. There is a lot of variation in how a tongue tie might look, where it is positioned, and how much it affects the tongue’s movement.
As a result, some individuals might be largely unaffected by a tongue tie, while for others it may affect breastfeeding or, less commonly, eating or oral hygiene.
According to the American Speech-Language-Hearing Association (ASHA), “there is virtually no evidence in the literature to establish a definite causal relationship between ankyloglossia [tongue tie] and speech disorders.”
A tongue tie rarely limits articulation. Most people who have a tongue tie can still make all the sounds necessary for speech, as long as their tongue tip is able to touch the alveolar ridge (behind the top front teeth).
It is important to conduct a thorough assessment with an experienced clinician before choosing to cut a tongue tie. This includes assessing the functional impact of the tongue tie and considering whether it is likely to alleviate any problems associated with breastfeeding, eating, or oral hygiene.
How can speech pathologists support people with their speech clarity?
Speech pathologists might:
- Conduct a thorough assessment of a person’s speech sound inventory to determine which sounds and words the person may be having difficulty producing clearly
- Conduct an oro-motor examination to check if there are any issues with strength, coordination or range of movement relating to the muscles of the mouth
- Discuss whether therapy is likely to be beneficial to improve speech sound production and what evidence-based therapy options are available
- Provide specific activities for home-based practise
At Box Hill Speech Pathology, we believe in offering a range of evidence-based therapy options for both children and adults.
Please head to our contact page for more information or call 9899 5494 to book an initial consultation.