Speech Sound Development from our Brisbane Speech Pathologists

What does ‘typical’ speech sound development look like?

When young children are learning to talk, they often will substitute trickier speech sounds for simpler sounds. Our Brisbane Speech Pathologists assess children to look at the patterns, or rules, they are using to simplify their speech.


These patterns or substitutions are called ‘Phonological Processes’ and are a typical part of speech sound development for children under the age of 5.

An assessment by one of our Brisbane Speech Pathologists would look at what phonological processes your child is using, and whether they are appropriate for their age.  The age ranges below are broad, and represent general advice.  Please seek assessment for your individual child.

Some common phonological processes seen in children are:

  • Voicing: swapping a voiceless sound for a voiced sound (pig → big) 
  • Final Consonant Deletion: dropping the final sound from a word (pig → pi) 
  • Fronting: swapping a sound that is made at the back of the mouth for one made at the front (dog → gog; king → ting) 
  • Stopping: swapping a long sound (i.e. fricative) for a short sound (i.e. stop) (zoo → doo; fish → pish, sun → dun)

(These Speech Sound Processes are typically corrected by ~3 – 3;5 years of age


  • Syllable Reduction: dropping a syllable from a large word (banana → nana) 
  • Cluster Reduction: dropping one or two sounds from a cluster of sounds (straw → taw)

(These Speech Sound Processes are typically corrected by ~4 – 4;5 years of age)


  • Gliding: swapping the /r/ and/or /l/ sound for /w/ and/or /y/ (ring → wing; lion → wion) 
  • Deaffrication: swapping a /ch/ or /j/ sound for a simpler sound (cheese → sheese) 
  • Labialisation: swapping a voiceless /th/ sound for a /f/ (thumb → fumb) 
  • Stopping voiced /th/: swapping a voiced /th/ sound for a short sound (feather → feader)

(These Speech Sound Processes are typically corrected by ~5-6 years of age)


Why is clear speech important?

We want our children to be great communicators!  Difficulties with speech clarity can lead to frustrations, behaviour and in some cases social difficulties.  Our speech pathologists help children speak clearly so they can:

  • reduce frustration
  • get clear messages across
  • become confident communicators
  • get ready for later literacy learning at school

When should my child’s speech be clear?

By the age of five, these phonological processes should be almost completely resolved and the child’s speech sounds should reflect adult speech.

At this point, children should also be using their speech sound system, to ‘play’ with words – indicating emerging pre-literacy skills (phonological awareness)

What types of speech sound difficulties are there?

When children present with speech sound difficulties that are not due to a motor disorder, they can be classified under one (or a mixture of) the following categories: a Phonological Delay, a Phonological Disorder, or an Articulation Disorder.


A Phonological Delay presents when children are using the typical phonological processes (listed above) within their speech; however these processes persist past the age of elimination.


If your child is presenting with some different phonological processes, this may indicate that they have a Phonological Disorder. A Phonological Disorder is characterised by the use of atypical/unusual Phonological Processes within speech.

Some atypical phonological processes that are often seen in young children with a Phonological Disorder are:


  • Backing: swapping a sound made at the front of the mouth for a sound made at the back of the mouth (dog → gog) 
  • Vowel Errors: swapping a vowel sound for a different vowel sound (peg → pag) 
  • Fricatives or Affricates replacing Stops: swapping a short sound (i.e. stop) for a longer sound (bird → zird; car → char) 
  • Inconsistent Sound Substitution: swapping a speech sound for a variety of different sounds (i.e. there is no identifiable pattern to child’s errors)


These phonological processes have a big impact on how easily a child’s speech is understood, and require Speech Pathology intervention to eliminate.


Alternatively, if your child is having difficulties correctly pronouncing sounds, they may be presenting with an Articulation Disorder. An Articulation Disorder presents when a child has difficulty accurately producing one or more speech sounds. A common example of this is a ‘lisp’, where the tongue comes forward between the teeth or air escapes from the sides of the mouth when producing the /s/ and /z/ sounds. Like atypical phonological processes, children with an Articulation Disorder require Speech Pathology intervention to improve their sound production.


If you are concerned about your child’s speech, it is best to get in contact with one of our Speech Pathologists as early as possible, as early intervention produces better therapy outcomes and helps children get ready for school.

Click here, to book your child’s speech clarity assessment online today!

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