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Copyright © Caroline Bowen 1998 All rights reserved
This page contains an article about speech development. Cite it as: Bowen, C. (1998). Typical speech development: the gradual acquisition of the speech sound system. Retrieved from http://www.speech-language-therapy.com/acquisition.html on December 4, 2009.
Anyone who has been around children who are under 5 years of age will know that their speech sounds are not pronounced correctly all the time. In fact a small, typically developing child's speech can be quite difficult to understand because his or her sound system is not yet organised like adult speech.
Many researchers have studied children's acquisition of individual speech sounds (phonetic development), and the way they organise these sounds into speech patterns (phonemic or phonological development). Drawing on this vast a varied body of research, Dr Sharynne McLeod of Charles Sturt University in Australia compiled the pdf file here, [Adobe Reader Required]. It contains an overview of typical speech development from a range of researchers around the world, working from a variety of theoretical perspectives.
Gregory L. Lof PhD presented a fascinating poster entitled Confusion about speech sound norms and their use in an online conference sponsored by Thinking Publications in 2004, exploding a few myths about normal (or 'normative') expectations and when to start therapy for particular speech sounds.
For Speech-Language Pathologists providing assessment and intervention for Speech Sound Disorders, a detailed understanding of typical ('normal') development is critical to the understanding of delayed and disordered development.
Table 1 provides a rough rule of thumb for how clearly your child should be speaking. If you are in doubt about your own child's speech sound development an assessment by a speech-language pathologist will quickly tell you if your child is 'on track' and making the right combination of correct sounds and 'errors' for their age. Table 1 is available separately here. See also: speech intelligibility from 12 to 48 months for a more detailed discussion.
| TABLE 1: How well words can be understood by parents |
By 24 months a child's speech is normally 50 -75% intelligible By 36 months a child's speech is normally 75-100% intelligible Source: Lynch, J.I., Brookshire, B.L., and Fox, D.R. (1980). A Parent - Child Cleft Palate Curriculum: Developing Speech and Language. CC Publications, Oregon. Page 102 |
The gradual process of acquiring adult speech patterns is called phonological development.
All children make predictable pronunciation errors (not really 'errors' at all, when you stop to think about it) when they are learning to talk like adults. These 'errors' are sometimes called phonological processes, or phonological deviations.
In Table 2 are the common phonological processes found in children's speech while they are learning the adult sound-system of English. Table 2 is available separately here.
| TABLE 2: Phonological Processes in Normal Speech Development | ||
PHONOLOGICAL PROCESS (Phonological Deviation) |
EXAMPLE |
DESCRIPTION |
Context sensitive voicing |
"Pig" is pronounced and "big" "Car" is pronounced as "gar" |
A voiceless sound is replaced by a voiced sound. In the examples given, /p/ is replaced by /b/, and /k/ is replaced by /g/. Other examples might include /t/ being replaced by /d/, or /f/ being replaced by /v/. |
Word-final devoicing |
"Red" is pronounced as "ret" "Bag" is pronounced as "bak" |
A final voiced consonant in a word is replaced by a voiceless consonant. Here, /d/ has been replaced by /t/ and /g/ has been replaced by /k/. |
Final consonant deletion |
"Home" is pronounced a "hoe" "Calf" is pronounced as "cah" |
The final consonant in the word is omitted. In these examples, /m/ is omitted (or deleted) from "home" and /f/ is omitted from "calf". |
Velar fronting |
"Kiss" is pronounced as "tiss" "Give" is pronounced as "div" "Wing" is pronounced as "win" |
A velar consonant, that is a sound that is normally made with the middle of the tongue in contact with the palate towards the back of the mouth, is replaced with consonant produced at the front of the mouth. Hence /k/ is replaced by /t/, /g/ is replaced by /d/, and 'ng' is replaced by /n/. |
Palatal fronting |
"Ship" is pronounced as "sip" "Measure" is pronounced as "mezza" |
The fricative consonants 'sh' and 'zh' are replaced by fricatives that are made further forward on the palate, towards the front teeth. 'sh' is replaced by /s/, and 'zh' is replaced by /z/. |
Consonant harmony |
"Cupboard" is pronounced as "pubbed" "dog" is pronounced as "gog" |
The pronunciation of the whole word is influenced by the presence of a particular sound in the word. In these examples: (1) the /b/ in "cupboard" causes the /k/ to be replaced /p/, which is the voiceless cognate of /b/, and (2) the /g/ in "dog" causes /d/ to be replaced by /g/. |
Weak syllable deletion |
Telephone is pronounced as "teffone" "Tidying" is pronounced as "tying" |
Syllables are either stressed or unstressed. In "telephone" and "tidying" the second syllable is "weak" or unstressed. In this phonological process, weak syllables are omitted when the child says the word. |
Cluster reduction |
"Spider" is pronounced as "pider" "Ant" is pronounced as "at" |
Consonant clusters occur when two or three consonants occur in a sequence in a word. In cluster reduction part of the cluster is omitted. In these examples /s/ has been deleted form "spider" and /n/ from "ant". |
Gliding of liquids |
"Real" is pronounced as "weal" "Leg" is pronounced as "yeg" |
The liquid consonants /l/ and /r/ are replaced by /w/ or 'y'. In these examples, /r/ in "real" is replaced by /w/, and /l/ in "leg" is replaced by 'y'. |
Stopping |
"Funny" is pronounced as "punny" "Jump" is pronounced as "dump" |
A fricative consonant (/f/ /v/ /s/ /z/, 'sh', 'zh', 'th' or /h/), or an affricate consonant ('ch' or /j/) is replaced by a stop consonant (/p/ /b/ /t/ /d/ /k/ or /g/). In these examples, /f/ in "funny" is replaced by /p/, and 'j' in "jump" is replaced by /d/. |
Phonological processes have usually 'gone' by the time a child is five years of age, though there is individual variation between children.
Table 3 lists the ages by which each of the processes are normally eliminated. Ages are expressed as years; months. For example, 3; 6 means 3 years 6 months. Table 3 is available separately here.
| TABLE 3: Ages by which Phonological Processes are Eliminated | ||
PHONOLOGICAL PROCESS |
EXAMPLE |
GONE BY APPROXIMATELY |
Context sensitive voicing |
pig = big |
3;0 |
Word-final de-voicing |
pig = pick |
3;0 |
Final consonant deletion |
comb = coe |
3;3 |
Fronting |
car = tar |
3;6 |
Consonant harmony |
mine = mime |
3;9 |
Weak syllable deletion |
elephant = efant |
4;0 |
Cluster reduction |
spoon = poon |
4;0 |
Gliding of liquids |
run = one |
5;0 |
Stopping /f/ |
fish = tish |
3;0 |
Stopping /s/ |
soap = dope |
3;0 |
Stopping /v/ |
very = berry |
3;6 |
Stopping /z/ |
zoo = doo |
3;6 |
Stopping 'sh' |
shop = dop |
4;6 |
Stopping 'j' |
jump = dump |
4;6 |
Stopping 'ch' |
chair = tare |
4;6 |
Stopping voiceless 'th' |
thing = ting |
5;0 |
Stopping voiced 'th' |
them = dem |
5;0 |
Table 4 outlines the ages by by which 75% of children in a carefully conducted study accurately use individual speech sounds in single test-words. These norms were established for a population of Australian children by Kilminster and Laird (1978).
In column 3, the term 'voiced' refers to the vibration of the vocal cords while the sound is being made. The term 'voiceless' is applied to sounds that are made without vocal cord vibration. The terms fricative, glide, stop, nasal, liquid and affricate refer to the way the sounds are made, or the "manner of articulation". The International Phonetic Alphabet Charts summarise this information here. Table 4 is available separately here.
| Table 4: Normal phonetic development | ||
Column 1 |
Column 2 |
Column 3
|
3 years |
h as in he zh as in measure y as in yes w as in we ng as in sing m as in me n as in no p as in up k as in car t as in to b as in be g as in go d as in do |
Voiceless fricative Voiced fricative Voiced glide Voiced glide Voiced nasal Voiced nasal Voiced nasal Voiceless stop Voiceless stop Voiceless stop Voiced stop Voiced stop Voiced stop |
3 years 6 months |
f as in if |
Voiceless fricative |
4 years |
l as in lay sh as in she ch as in chew |
Voiced liquid Voiceless fricative Voiceless affricate |
4 years 6 months |
j as in jaw s as in so z as in is |
Voiced affricate Voiceless fricative Voiced fricative |
5 years |
r as in red |
Voiced liquid |
6 years |
v as in Vegemite |
Voiced fricative |
8 years |
th as in this |
Voiced fricative |
8 years 6 months |
th as in thing |
Voiceless fricative |
Bowen, C, (1998). Developmental phonological disorders. A practical guide for families and teachers. Melbourne: ACER Press.
Grunwell, P. (1997). Natural phonology. In M. Ball & R. Kent (Eds.), The new phonologies: Developments in clinical linguistics. San Deigo: Singular Publishing Group, Inc.
Kilminster, M.G.E., & Laird, E.M. (1978) Articulation development in children aged three to nine years. Australian Journal of Human Communication Disorders, 6, 1, 23-30.
Lof, G.L. (2004). Confusion about speech sound norms and their use. Thinking Publications Online Conference. www.thinkingpublications.com/LangConf04/OLCIntro.html Accessed April 21 2004.
Lynch, J.I., Brookshire, B.L., & Fox, D.R. (1980). A Parent - Child Cleft Palate Curriculum: Developing Speech and Language. CC Publications, Oregon.
From: http://www.asha.org/public/speech/development/chart.htm
The development of communication skills begins in infancy, before the emergence of the first word. Any speech or language problem is likely to have a significant effect on the child's social and academic skills and behavior. The earlier a child's speech and language problems are identified and treated, the less likely it is that problems will persist or get worse. Early speech and language intervention can help children be more successful with reading, writing, schoolwork, and interpersonal relationships.
This information represents, on average, the age by which most monolingual speaking children will accomplish the listed skills. Children typically do not master all items in a category until they reach the upper age in each age range. Just because your child has not accomplished one skill within an age range does not mean the child has a disorder. However, if you have answered no to the majority of items in an age range, seek the advice of an ASHA-certified speech-language pathologist or audiologist .
Speech and Articulation Development Chart from talkingchild.com.
In the linked chart, each solid bar indicates when children generally master the specified sounds. This chart depicts a range of development and should only be used as a general guide.
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