Phonological Process Definition Examples Age Eliminated By
Backing***
Substitution of a sound produced in the front of the mouth, with a
sound produced in the back of the mouth
"cop" for "top"
"boke" for boat
No information
available
Fronting
(Velar or Palatal)
Substitution of a sound produced in the back of the mouth, with a
sound produced in the front of the mouth
"doat" for goat
"tandy" for candy
"sip" for ship
3-6
Gliding The substitution for a glide sound (w, y) for a liquid sound (I, r )
"pway" for play
"wun: for run
"yewo" for yellow
5-0
Stopping
Substitution of a stop sound (b,p,t,d,k,g ) for a fricative (f,v,s,z,h,
th,sh and zh ) or affricate sound (ch or j)
"tope" for soap
"cat" for catch
"puddle" for puzzle
/f/ & /s/ = 3-0
/v/ & /z/ = 3-6
sh, ch & j = 4-6
th = 5-0
Vowelization or
Vocalization
Substitution of a vowel sound for a liquid (l, r) sound
"Hay-uh" for hair
"peopo" for people
No information
available
Phonological Process Definition Examples Age Eliminated By
Cluster Reduction
Reduction of a consonant cluster (two consonants next to one
another) to a single sound
"tuck" for truck
"sool" for school
4-0
Final Consonant
Delition Deletion of the final sound (consnant) in a word
"cuh" for cup
"dah" for dog
3-0
Initial Consonant
Deletion***
Deletion of the initial sound (consnant) in a word
"up" for cup
"uv" for love
No Information
Available
Unstressed Syllable
Deletion
Deletion of an unstressed syllable
"puter" for computer
"nana" for banana
4-0
Phonological Process Definition Examples Age Eliminated By
Assimilation
(Harmony)
Also called "harmony", refers to when a sound starts to sound like a
surrounding sound
"beb" for bed
"gank" for thank
3-9
Coalescence
Substitution of a phoneme that is different from the two adjacent
phonemes yet takes on features of the target
"foke" for smoke
"lath" for last
No Information
Available
Voicing or Devoicing
Voicing: Athe substitution of a voiced consonant for an unvoiced
consonant (typically in the beginning of a word) Devoicing: the
substitution of a voiceless consonant for a voiced consnant
"gup" for cup
"back" for bag
3-0
Reduplication Repitition of a complete or incomplete sylllable
"wawa" for water
"baba" for bottle
3-0
This chart was created by Katie Yeh, MA CCC-SLP 2011 using the following references:
Bowen, Caroline, (1998). Typical speech development: A gradual acquisition of the speech sound system. Retrieved from http://speech-language-
therapy.com/acquisition.html (9-25-2011).
Shipley, K.G. & McAfee, J.G.,(1998). Assessment in speech-language pathology: A resource manual (2nd edition). San Diego, CA: Singular Publishing Group.
Hegde, M.N., (2001). Pocket Guide to Assessment in Speech-Language Pathology (2nd edition). San Diego, CA: Singular Publishing Group.
Common Phonological Processes*
*This list is not exhaustive. This is simply a list of more commonly seen phonological processes. Please note that some children will never
use certain processes.
**These are the most common phonological processes seen in normal speech acquisition
***These processes are usually seen in more severe phonological delays
Syllable Structure Processes: Sound changes where sounds or syllables become reduced, omitted, or repeated.
Substitution Processes: Sound changes where one sound class is replaced for another class of sounds
Assimilation Processes: Sound changes where one sound will start to sound like another, surrounding sound
