Phonological Processes and Elimination in Typically Developing Child

http://www.hanen.org/Guidebooks---DVDs/Parents/It-Takes-Two-to-Talk.aspx 

A concerned parent asked me about the phonological development and processes in typically developing child. In replay I presented him with two tables created by Caroline Bowen. I frequently use the tables for my clients.

“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 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.” Caroline Bowen

TABLE 2: Phonological Processes in Typical Speech Development COPYRIGHT ©1999 CAROLINE BOWEN
PHONOLOGICAL PROCESS (Phonological Deviation)	EXAMPLE	DESCRIPTION
Context sensitive voicing	"Pig" is pronounced as  "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 Here, /d/ has been replaced by /t/ and /g/ has been replaced by /k/.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/.

TABLE 3: Elimination of Phonological Processes

Phonological processes are typically gone by these ages (in years ; months)

COPYRIGHT ©1999 CAROLINE BOWEN

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 ship = sip	3;6
Consonant harmony	mine = mime kittycat = tittytat	3;9
Weak syllable deletion	elephant = efant potato = tato television =tevision banana = nana	4;0
Cluster reduction	spoon = poon train = chain clean = keen	4;0
Gliding of liquids	run = one leg = weg leg = yeg	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

References:
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.

Check Caroline Bowen’s page http://www.speech-language-therapy.com/  

If Someone prefers more visual version can go to Tracy Brading page to see the chart 

http://firstyears.org/c4/u6/alpha.htm

"By the age of ___________, 90% of children have suppressed the phonological process of _________________."

Age 3

AF = Affrication (e.g. "cho" for "show") 
BA = Backing (e.g. "buk" for "bus") 
VC = Voicing Change (e.g. "dief" for "thief")

Age 4

CD = Consonant Deletion (e.g. "bu" for "boot") 
DE = Deaffrication (e.g. "sew" for "chew")

Age 5

FR = Fronting (e.g. "tey" for "key") 
SY = Syllable Deletion (e.g. "mado" for "tomato")

Age 6

AL = Alveolarization (e.g. "tum" for "thumb") 
CR = Cluster Reduction (e.g. "poon" for "spoon") 
CS = Cluster Simplification (e.g. "twa" for "tray") 
GL = Gliding (e.g. "wug" for "rug") 
SD = Stridency Deletion (e.g. "but" for "bus") 
ST = Stopping (e.g. "toup" for "soup") 
VO = Vowelization (e.g. "penco" for "pencil")

Age 8

LA = Labialization (e.g. "fad" for "sad")

Reference:

Lowe, R.J.  (2000) ALPHA (Assessment Link Between Phonology and Articulation Phonology) Revised Test of Phonology.  (2000)  Mifflinville, PA: ALPHA Speech & Language Resources