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Familiar
questions
A
question from the parent of a four year old with difficult-to-understand speech:
What is the difference between an
articulation disorder and a phonological disorder? How can you
tell the difference? Are they treated differently?
A question from a
colleague:
Although I have been a school-based SLP for over 20 years I
have to say I am confused about the distinction between phonetic
speech sound disorders, and phonemic speech sound disorders. In
simple terms, what exactly is the difference?
Speech
Speech is the spoken medium of
language. Speech has a phonetic level and a
phonological (or phonemic) level.
Phonetic
(articulation) level
The phonetic level takes care of the
motor act of producing the vowels and consonants, so that we have
a repertoire all the sounds we need in order to speak our language.
Phonological
(phonemic) level
The phonological or phonemic level is in charge of the
brainwork that goes into
organising the
speech sounds into patterns of sound contrasts so that we
can make sense when we talk.
Articulation
(phonetic) disorder
In essence, an
articulation disorder is a SPEECH disorder that affects the PHONETIC
level. The child has difficulty saying particular consonants and
vowels. The reason for this may be unknown (e.g., children with
functional
speech disorders who do NOT have serious
problems with muscle function); or the reason may be known (e.g.,
children with dysarthria who DO have serious problems with muscle
function).
Typical speech
development
Speech-Language Pathologists make a
detailed study of all aspects of normal human communication and its
development in the areas of voice, speech, language, fluency and
pragmatics. A thorough knowledge and understanding of what
science reveals about typical
speech development is critical to our understanding of
children's speech sound
disorders.
Language
Language has been called the symbolisation of thought. It is a
learned code, or system of rules that enables us to communicate
ideas and express wants and needs. Reading, writing, gesturing and
speaking are all forms of language. Language falls into two main
divisions: receptive language (understanding what is said, written
or signed); and, expressive language (speaking, writing or
signing).
Phonological
disorder
A phonological disorder is a LANGUAGE
disorder that affects the PHONOLOGICAL
(phonemic) level. The child has difficulty organising their speech sounds
into a system of sound contrasts (phonemic contrasts).
What is
the difference between an articulation disorder and a phonological
disorder?
In an
articulation
disorder the child's
difficulty is at a phonetic level.
That is, they have trouble making the individual speech sounds.
In a phonological
disorder the child's difficulty is at a phonemic level
(in the mind). This "phonemic level"
is sometimes referred to as "the linguistic level" or
"a cognitive level".
Co-occurrence
An articulation
disorder and a phonological disorder can co-occur. That
is, the same child can have BOTH.
Assessment and
diagnosis
Because of their
knowledge-base, Speech-Language Pathologists (SLPs) are able
to distinguish between the many speech and language disorders they have to assess (or "differentially
diagnose") in the course of their work.
The assessment process
typically involve screening the child's communication skills in a general way, and then forming an
hypothesis about the nature of any
apparent difficulties.
If speech clarity is a
problem the SLP will examine both the
PHONETIC and the PHONOLOGICAL aspects of the child's
speech. The tests chosen will depend on the child's presentation
and the theoretical beliefs of the clinician.
Use of
terminology
Some SLPs use the term
"articulation disorder" very loosely, especially when they are explaining these
complex ideas to people who do not have
a background in linguistics or speech pathology. Indeed, they
may refer to a "phonological disorder" as an
"articulation disorder".
It can often be quite
helpful for parents to ask their SLP what
they mean by the particular terms they use.
"Functional"?
The term
"functional" speech disorder' is usually equated with the
concept of "cause unknown" and these disorders are often referred to
as speech disorders of unknown origin.
Although
we cannot "prove" or "demonstrate" what has
"caused" a speech sound disorder in a particular child,
we can often form justifiable hypotheses regarding the likely
cause, given a child's history (Flipsen, 2002). Factors such as
family history, frequent otitis media, developmental apraxia of
speech, and psychosocial factors (Shriberg, 1993) may be
considered.
Developmental?
The word
"developmental" in "developmental
phonological disorders", "developmental
dysarthria", and "developmental apraxia of speech"
(the preferred term is "childhood apraxia of speech") simply denotes that the disorders occur in children. The word
"developmental" is not appended to functional speech
disorders, which occur in both children and adults.
Intervention
There is information about the
treatment of children's speech sound disorders
here.
Discussion
The phonological therapy
discussion group provides communication disorders professionals with an
opportunity to ask and answer questions and explore theoretical
and research issues related to young children's speech sound
disorders in general, and developmental phonological disorders,
articulation disorders, and developmental apraxia of speech in
particular. The emphasis is on theoretically sound, evidence-based clinical assessment and
intervention.
References
Flipsen, P. Jr. (2002, May).
Causes and speech sound disorders. Why worry? Presentation
at the Speech Pathology Australia National Conference: Alice
Springs, Northern Territory, Australia.
Shriberg, L.D. (1993). Four new speech and prosody-voice measures for
genetics research and other studies in developmental phonological
disorders. Journal
of Speech and Hearing Research, 36, 105-140. |