Speech Deficits and Speech Language Pathologists - Fact Sheet
The ability to communicate effectively is a skill
that most people take for granted. It isn't often that we stop to
think about the complex nature of speech and language.
For example, have you ever stopped to consider how our brain is
able to process over 200 words per minute every hour of the day
without tiring? Or why, when you finish reading this sentence, your
voice will instinctively rise to mark the use of question? Further,
how come you know that the combination mgla could not possibly be a
word, but the combination flast is permissible?
Speech Language Pathologists
These and other questions are investigated by speech language
pathologists (SLP). Formerly known as speech therapy, the allied
health discipline of speech language pathology encompasses the
diagnosis, assessment and treatment of communication and swallowing
disorders. Communication - the means by which we understand and
make ourselves understood - can breakdown in the areas of speech,
fluency, voice, language use, hearing, reading and writing. As 1 in
7 Australians experience some form of communication disability, the
role of the SLP in hospitals, educational settings, nursing homes
as well as specialist and private practice, is growing.
SLP's work as part of a multidisciplinary team, often alongside
physiotherapists, occupational therapists, doctors and nurses. As
the caseload of the SLP is so varied, their responsibilities may
include treatment of swallowing disorders following stroke, working
with parents of a new born baby with a cleft palate, reducing voice
strain in teachers and amongst many others, providing information
and rehabilitation to patients who have suffered an acquired brain
As with all frameworks for speech pathology intervention, it is
the aim of the SLP to treat not only the presenting impairments,
but to also determine their impact on a patient's activities and
Consequently, it is the role of an SLP to not only diagnose and
assess patients, but to consider the patient as a whole,
understanding the impact of impairment on a patient's social,
emotional and vocational aspects of life.
Speech, Language and Acquired Brain Injury
Human communication comprises three fundamental neurological
processes that may become impaired as the result of an acquired
brain injury. The overall aim of these processes is to facilitate
effective communication, in which we can plan and execute exactly
what we want to say. The three steps involved include:
- Understanding and organisation of a thought, e.g. knowing that
saying "hello" requires the production of 4 distinct sounds
- Programming of the motor components, e.g. knowing that to
produce the /h/ you need to release a quiet stream of air from the
back of your throat.
- Execution of the thought, e.g. actually producing the word
"hello" by using certain speech muscles.
A breakdown can occur at any one or more of these stages,
depending on the location and severity of the acquired brain
A breakdown at Stage 1- Aphasia.
Aphasia is characterised by an impaired understanding and
production of language and is usually the result of damage to the
left or "language competent" half of the brain. People with aphasia
may find it difficult to
- Participate in a conversation, particularly in a noisy
- Comprehend jokes or sarcasm,
- Write a letter or use the telephone,
- Use money or understand numbers
In terms of neurology, two major areas can account for the specific
deficits seen in patients with aphasia:
- A motor speech-language area, or Broca's area
- A sensory speech-language area, or Wernicke's area.
Essentially, a patient with Broca's aphasia will produce
non-fluent, slow and effortful speech, while a patient with
Wernicke's aphasia will produce fluent but confused speech.
A language sample from a patient with Broca's aphasia,
explaining a scene in a picture:
"Uh…mother and dad…no…mother…dishes…uh…running over…water…and
floor" From Brookshire, 2003.
A patient with Wernicke's Aphasia in conversation:
"His wife saw the wonting to wofin to a house with the umbelor.
Then he left the wonding then he too the womin and to the umbrella
up stairs." From Goodglass & Kaplan, 1983.
Aphasia is not considered by most to be a disorder that can be
cured, however the overall aim of speech and language therapy is to
increase an individuals potential to function effectively in their
own environment, to facilitate meaningful relationships and restore
self esteem and independence.
A breakdown at Stage 2- Apraxia
Apraxia of speech (AOS) reflects an impaired capacity to plan the
movements necessary to direct speech. AOS can occur on its own as a
result of an acquired brain injury, however it is also seen as a
secondary disorder to aphasia. AOS can also occur in childhood.
A patient with AOS is unable to produce correct articulation and
flow of speech, despite having functioning speech musculature.
Essentially, the impairment occurs at the level of planing the
speech output. Therefore, although the patient has enough muscle
strength and coordination to produce the word "hello", they have an
impaired ability to plan exactly how to move their lips, tongue and
other speech organs in order to produce the word. As a consequence,
a patient with AOS will often be seen groping for words as they
attempt to program their speech musculature.
The goal of the SLP working with patients with AOS is to
maximise effectiveness, efficiency and naturalness of speech.
Speech programs may need to be relearned, for example the program
that tells us instinctively how to produce the /h/ in hello, in
order to restore lost function.
A breakdown in Stage 3- Dysarthria
Dysarthria is the term given to a group of disorders that
reflect impairment in the actual speech muscles. Unlike AOS,
patients with dysarthria can plan their speech output, but due to
damaged central or peripheral nerves, no longer have the strength
or coordination to execute speech.
As a result of nerve damage, for example cranial nerve damage
following a motor vehicle accident, various components of the
speech system may become impaired. A patient may experience
difficulties in respiration control, articulation, resonance or
phonation. These difficulties can then present as lowered strength,
coordination, range, steadiness or accuracy of speech
References and further information
- Chapey, R. (2001). Language Intervention Strategies in Aphasia
and Related Neurogenic Communication Disorders. Lippincott Williams
and Wilkins: Sydney.
- Brookshire, R. (2003). Introduction to Communication Disorders.
Mosby: St Lois.
- Duffy, J. (2005). Motor Speech Disorders. Substrates,
Differential Diagnosis and Management. Elsevier Mosby:
- Goodglass, H. (1983). The Assessment of Aphasia and Related
Disorders. Lea and Febiger: Philadelphia.
- Speech Pathology Australia Website, 2007. http://www.speechpathologyaustralia.org.au