Talking About Phonological Disorders
by Cheryl D. Lindsay, M.S., S-LP
Explaining phonological disorders is not an easy task! Hold on to your hat (and your brain!). In order to define this term, it helps to understand what happens when we speak. The following model includes three simplified steps of speech production and includes the key terms phonological representation and articulation.
Step # 1. Phonological representation is the abstract representation, or “the picture” of the speech sounds, that are stored in the child’s mind:
e.g. /m/ /a/ /m/ /a/
Step # 2. Using this representation or “picture”, specific systems in the brain generate a rough plan. This plan or “blueprint” sends instructions in syllable chunks, to the muscle groups involved in saying the target word:
e.g. /ma/ /ma/
Step # 3. Articulation is the speech output, or when articulators produce the sounds, in sequence, to form “the spoken word”:
(Adapted from Model of speech production. Laura M. Justice, 2010)
Articulation then, is the correct movement of all parts of the speech sound system, (tongue, lips, larynx, teeth, hard palate, velum, jaw, nose and mouth) to produce intelligible speech (Step # 3, “the spoken word”).
Phonology, however, refers to the rules that govern the sound system to create language. These rules oversee speech sound combinations and their productions, generating intelligible speech. (Step # 1, “the picture”).
When these rules are “broken”, we see error patterns (also called phonological processes, as discussed in last month’s column). An example of one error pattern occurs when sounds made in the back of the mouth, like /k/ and /g/, are replaced by sounds that are made in the front of the mouth, or as /t/, /d/. The words /car/ and /go/ are instead produced as /tar/ and /doe/. This process is referred to as “velar fronting”.
A phonological delay is different than a phonological disorder. If these error patterns persist beyond normal developmental milestones, this may signal a phonological disorder and be cause for concern.
“Developmental Phonological Disorders (also called “phonological impairments” or “phonological disorders”) are a group of language disorders that affect children’s ability to develop easily understood speech by the time they are four years old, and, in some cases, their ability to learn to read and spell.
Phonological disorders involve difficulty in learning and organizing all the sounds needed for clear speech, reading and spelling. They are disorders that tend to run in families.
Developmental phonological disorders may occur in conjunction with other communication disorders such as stuttering, specific language impairment, or childhood apraxia of speech.”
Bowen, C. (1998). Developmental phonological disorders: Information for families. Retrieved from http://www.speech-language-therapy.com/parentinfo.html
Children with Phonological disorders typically:
1. use a small number of sounds
2. use more than one phonological process or type of error
ex: velar fronting and final consonant deletion
3. use one phoneme to represent a category
eg. /t/ for all fricatives /th/, /f/, sh/ and /s/
4. use atypical processes eg. instead of the usual
“tain” for “train”, the child uses “rain” for “train”
(Laura M. Justice, 2010)
A speech language pathologist can help to identify phonological delays and disorders.
Isn’t it a miracle, and still somewhat a mystery, that we learn to say what we think?
(Next Month: Childhood Apraxia of Speech)