DIAGNOSING AND TREATING
ACQUIRED (ADULT) APRAXIA OF
SPEECH
Don Freed
October 14, 2014
CSHA Hot Topics
Children’s Hospital of Central California
AOS Defined
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Apraxia of speech is a phonetic-motoric disorder of speech
production. It is caused by inefficiencies in the translation of wellformed and filled phonologic frames into previously learned
kinematic information used for carrying out intended movements.
These inefficiencies result in intra- and interarticulator temporal
and spatial segmental and prosodic distortions. It is characterized
by distortions of segment and intersegment transitionalization and
coarticulation resulting in extended durations of consonants;
vowels; and time between sounds, syllables and words. These
distortions are often perceived as sound substitutions and as the
misassignment of stress and other phrasal and sentence-level
prosodic abnormalities. Errors are relatively consistent in location
within the utterance and invariable in type. It is not attributable to
deficits of muscle tone or reflexes, nor to primary deficits in the
processing of sensory (auditory, tactile, kinesthetic, proprioceptive),
or language information. In its extremely infrequently occurring
isolated form, it is not accompanied by the above mentioned
deficits of basic motor physiology, perception, or language.
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McNeil, Robin, and Schmidt (2009)
Key Elements of This AOS Definition
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1. When our cognitive system selects a word for
speech production, the word’s phonological
representations are combined to form a
phonological word “frame.”
2. In cases of AOS, correct phonological frames
are poorly transformed into speech movements.
3. This results in speech that has timing and
movement errors for sounds, syllables, and words.
4. The timing problem causes speech that is slow,
with lengthened productions of vowels,
consonants, or both.
5. In addition, the timing problem causes pauses
between phonemes, syllables, words, and phrases.
Key Elements of This AOS Definition
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6. The movement problem causes distorted
productions of vowels and consonants.
7. These distortions can sometimes sound like
phoneme substitutions, but they actually are
distortions of the correct target sound (however, real
substitutions can occur in AOS).
8. These timing and movement problems contribute
significantly to prosody errors in connected speech.
9. On repeated utterances, articulation errors in AOS
are generally consistent for type of error (distortion,
substitution, omission) and for location.
10. AOS errors are not caused by muscle, sensory, or
language deficits.
11. Pure AOS is very rare.
Primary Clinical Characteristics of
AOS
The following six behaviors are strongly indicative of apraxia of
speech when, as a group, they are present in a patient’s speech
(Wambaugh, Duffy, McNeil, Robin, & Rogers, 2006):
 The patient demonstrates prosody abnormalities.
 The patient has a slow speech rate characterized by
lengthened productions of vowels, consonants, or both.
 The patient has a slow speech rate with pauses between
phrases, words, syllables, or phonemes. These pauses may
often be filled with a schwa.
 The patient produces consonants and vowels that are
distorted.
 The patient has phoneme substitutions that also are
distorted.
 The patient demonstrates articulation errors during
repeated utterances that generally are consistent for type of
error (omission, distortion, substitution) and for location.
Nondiscriminative Clinical
Characteristics of AOS
The following behaviors only are suggestive of AOS when
they are found in a patient’s speech because they also can
be found frequently in other disorders, such as fluent
aphasia. By themselves, these behaviors should not be used
to make the diagnosis of apraxia of speech:
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The patient has short periods of error-free speech.
The patient’s automatic, overlearned speech (e.g.,
counting 1 to 10) is produced better than propositional
speech (e.g., describing the prior day’s activities).
The patient self-corrects errors and shows other signs
of error awareness.
Nondiscriminative Clinical
Characteristics of AOS (cont.)
The patient has difficulty initiating speech.
 The patient’s speech errors increase as
word length increases.
 The patient has perseverative errors or
movements.
 The patient demonstrates articulatory
groping, either visually, audibly, or both.
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Clinical Characteristics Usually
Found in Other Disorders
The following behaviors are more likely to be found in
other disorders and therefore should not be used to
make the diagnosis of apraxia of speech:
 The patient demonstrates a difference between
expressive and receptive speech and language
abilities.
 The patient has transposition errors on phonemes or
syllables. “Vellitision” for television (a type of error
more common in conduction aphasia, for example).
 The patient has anticipatory articulation errors.
“Papple” for apple (a type of error more common in
fluent aphasia).
 Note: The presence of limb apraxia or nonverbal oral
apraxia does necessarily indicate a diagnosis of
apraxia of speech.
Clinical Characteristics Ruling Out
Apraxia of Speech
These three behaviors are exclusionary
characteristics; they do not occur in the
speech of patients with apraxia of speech.
Their presence in a patient’s utterances
indicate that apraxia of speech would not be
the correct diagnosis.
 The patient demonstrates a fast rate of
speech.
 The patient has a normal rate of speech.
 The patient demonstrates normal prosody.
Assessment of AOS
There is no widely accepted, published,
standardized test for adult AOS.
 Many current researchers use a collection
of informal assessment tasks to detect the
speech errors of AOS in their participants.
 For example, Wambaugh has repeatedly
used the following assessment tasks in
her recent AOS research:
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Assessment of AOS (cont.)
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(a) The Increasing Word Length (thickthicker-thickening) and Repeated Trials
(repeat target word 3x) subtests of the
Apraxia Battery for Adults—Second Edition
(b) narrative and procedural discourse tasks
(c) Assessment of Intelligibility of Dysarthric
Speech
(d) consonant production probe
(e) sentence repetition task
(f ) multisyllabic word repetition task.
Assessment of AOS (cont.)
Hegde and Freed’s (2011) informal AOS
assessment recommended the following
tasks detecting this disorder:
 Repeating multisyllabic words
 Repeating phrases
 Repeating sentences
 Reciting overlearned sequences (e.g., days of
week, counting 1-20)
 Increasing word length
 Repeated trials (3x)
 Comparing AMRs and SMRs
 Connected speech sample
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Assessment of AOS (cont.)
In general, these types of informal tasks
seem to be effective in evoking the core
speech errors of AOS.
 To make the most accurate diagnosis of AOS,
a number of researchers report that they
are looking for the speech errors that are on
the “McNiel checklist”:
 Slow rate of speech
 Prolonged segment/intersegment durations
 Distortions/distorted sound substitutions
 Errors consistent in type and location
 Prosodic abnormalities
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Differential Diagnosis: AOS and
Fluent Aphasia
Patients with apraxia of speech often have anterior
brain damage and right hemiparesis. Patients with
aphasia who produce literal paraphasias often have
posterior brain damage and do not have hemiparesis.
 Patients with apraxia of speech usually have a cooccurring Broca’s aphasia. Patients who produce
literal paraphasias usually have Wernicke’s or
conduction aphasia.
 Patients with apraxia of speech usually have disturbed
prosody, often because they are frequently stopping
or slowing their speech as they search for correct
articulatory positions. Patients with aphasia usually
produce their literal paraphasic errors in a flow of
speech that has normal prosody.
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Differential Diagnosis: AOS and
Fluent Aphasia
Patients with apraxia of speech may have difficulty
initiating speech because they are searching for
the correct articulatory position of the first
phoneme in an utterance. Patients with aphasia
who produce literal paraphasias typically do not
have as much trouble initiating an utterance.
 The phoneme and syllable substitutions in apraxia
of speech are usually close to the intended
sounds. For example, a /b/ might be substituted
for a /d/. The substitutions in literal paraphasias
can be far off target from the intended sounds,
such as a nasal consonant being used in place of a
stop consonant, or perhaps even a vowel being
substituted for a consonant.
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Differential Diagnosis: AOS and
Fluent Aphasia
Phoneme distortions often are present in cases of
apraxia of speech; they are rare in the speech of
patients with literal paraphasias.
 Self-initiated efforts at fixing articulation errors
usually do not result in improvements in apraxia of
speech. In cases of literal paraphasia, these self-repair
efforts often can result in improved articulation.
 In apraxia of speech, patients often have prolonged
transitions when moving from phoneme to phoneme
and from word to word (even when the words are
articulated correctly); they also often prolong vowels
in multisyllabic words and sentences. Patients with
literal paraphasias demonstrate much more normal
movement transition times in their speech.
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Differential Diagnosis: AOS and
Fluent Aphasia
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An overall slow speech rate for phrases and
sentences is found in cases of apraxia of
speech, even when the words are produced
correctly. In cases of literal paraphasias, the
speech rate is within normal limits during
error-free utterances.
When patients with apraxia of speech
attempt to increase their speech rate,
phoneme production errors also increase,
often quite noticeably. Patients with literal
paraphasias usually can increase their speech
rate and maintain accurate phoneme
production.
Treating AOS:
Sound Production
Treatment
Types of AOS Treatments
Articulatory kinematic—use of modeling, repetition, and
artic placement (e.g., 8-Step Continuum and SPT).
 Rate and rhythm—decreases artic timing errors by
contolling rate of speech (e.g., using metronome or
computer to set an optimal rate of speech).
 AAC—creates a comprehensive communication system
for the patient using writing, gestures, pictures, and
drawing or using a specialized electronic device.
 Intersystemic facilitation and reorganization treatment—
supplement speech with a stronger communicative
ability, such as combining good gesturing skills with
limited verbal output.
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Sound Production Treatment (SPT)
SPT is an articulatory-kinematic
treatment.
 It combines the following elements into
its treatment steps:
 modeling-repetition
 minimal contrast practice (sometimes)
 integral stimulation
 articulatory placement cueing
 repeated practice
 verbal feedback
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Sound Production Treatment (SPT)
SPT was developed about 15 years ago.
 It is based on prior AOS tx, and motor learning
research, such as using blocked and random practice
and reduced feedback schedules.
 “SPT has received more extensive and systematic study
than any other specific treatment for AOS.” (p. 815)
 “SPT has been shown to improve articulatory accuracy
of consonant production in words, phrases, and
sentences for trained and untrained items****.” (p. 815)
 **** Response generalization to untrained phonemes
has been minimal.
 Maintenance of tx effects has been demonstrated out to
10 weeks, with a slow decline after that.
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Wambaugh and Mauszycki (2010)
Sound Production Treatment (SPT)
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Here is a recommended procedure for getting started with
SPT for a patient with AOS:
Complete your assessment of the patient’s speech and
determine which phonemes are most in error. (In order of
difficulty, affricates are typically the hardest, then fricatives,
then stops, nasals, semivowels, and vowels. Also, back sounds
are usually more difficult than front sounds.)
Determine the utterance length where your patient’s
productions of the target phonemes begin to breakdown
(e.g., monosyllabic words, multisyllabic words, phrases, or
sentences).
Choose three difficult phonemes for treatment.
Develop about 30 tx stimuli for each phoneme at the
“breakdown” utterance length. Include the target sound in
the initial, medial, and final positions (as appropriate).
Note: If you are working at the monosyllabic word level, you
will need to create a minimal pair tx stimulus for each word.
Why Include the Minimal Pairs?
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“The minimal contrast tasks used in SPT
require production of words in which target
contrasts are minimally different (e.g., shocksock; conical-comical). It is believed that the
use of minimal contrast pairs provides a
context for practicing and refining the
movement patterns necessary to distinguish
among minimally different sounds and that
such practice is important when errors are
the result of a movement programming
disorder.” (p. 450)
Duffy (2013)
Sound Production Treatment (SPT)
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Sound Production Treatment Hierarchy (Minimal Pair Version)
1. Therapist says word and requests repetition.
◦ (a) If correct, request additional repetitions (5 times*) and go
to next item.
◦ (b) If incorrect, give feedback and say, “Now let’s try a
different word” and produce minimal pair word and request a
repetition.
If correct, give feedback and say, “Now let’s go back to the other
word” and go to #2 with the target word.
If incorrect, give feedback, attempt with integral stimulation up
to 3 times, then go to #2 with the target word.
2. Therapist shows the printed letter of the target sound, says
word, and requests repetition.
◦ (a) If correct, request addition repetitions (5 times) and go to
the next item.
◦ (b) If incorrect, go to #3.
Sound Production Treatment (SPT)
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3. Therapist uses integral stimulation: “Watch me, listen to me,
say it with me” up to three times.
◦ (a) If correct, request addition repetitions (5 times) and go to
the next item.
◦ (b) If incorrect, go to #4.
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4. Therapist provides verbal articulatory placement cues
appropriate to error. Therapist elicits production using integral
stimulation.
◦ (a) If correct, request addition repetitions (5 times) and go to
the next item.
◦ (b) If incorrect, go to next item.
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*Provide feedback for accuracy for approximately 3 of the 5
productions
Note: the hierarchy is response-contingent (subsequent steps are
used only upon incorrect production) and does not reverse
directions.
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Sound Production Treatment (SPT)
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Sound Production Treatment Hierarchy
(Multisyllabic Word, Phrase, or Sentence Version)
1. The SLP provides a verbal model of the target word and
requests a repetition. If correct, ask for 5 repetitions and
then present next item. If wrong, go to #2.
2. The SLP indicates the printed letter(s) representing the
target sound, instructs the participant to attend to this
sound, provides another model, and requests a repetition. If
correct, ask for 5 repetitions and then present next item. If
wrong, go to #3.
3. The SLP says, “watch me, listen to me, say it with me” (i.e.,
integral stimulation) and attempts simultaneous production
for a maximum of three times. If correct, ask for 5
repetitions and then present next item. If wrong, go to #4.
4. The SLP provides articulatory placement cues appropriate
to the sound production error and then repeats the
procedures used in the previous step.
5. The SLP presents the next item.
Sample Treatment Stimuli Lists
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Sample Stop List (Monosyllabic words and
minimal pairs)
Buy -- Why
Bee -- We
Bite -- White
Bay -- Way
Bore -- War
Beep -- Weep
Ben -- When
Bill -- Will
Boo -- Woo
Bait -- Wait
Sample Treatment Stimuli Lists
Sample initial affricate list (Phrases)
Charmed life
Charley horse
Jump the gun
Chit chat
Chick flick
Just in time
Chow down
Judge not
Jam packed
Channel surfing
Sample Treatment Stimuli Lists
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Sample Stop List (Sentences)
Pat buys a big bike.
Ted keeps bad dogs.
Deb makes pumpkin pie.
Bobby’s key is gold.
Cook bakes a cake.
Dotty picks a cat.
The puppy eats bugs.
The boat docks today.
Dad packs the bag.
Todd is a good boy.
Sample Treatment Stimuli Lists
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Sample Fricative List (Sentences)
Susan is shy.
She finds fuzz.
Soda is fizzy.
The zoo is fun.
My shoes seem stiff.
Sue fills the vase.
Something falls off.
The shell is thin.
Cindy is special.
The view is fine.
Sample Treatment Stimuli Lists
Sample Mixed Consonants (Sentences)
Sue eats cheese for lunch.
We give Cindy a lift.
Jane is your good friend.
Very few people see Jim.
You choose the first one.
Toast is good for lunch.
I sometimes go with John.
This book is very funny.
Chew your food carefully.
Charlie never sees that show.
References
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Dabul, B. (2000). Apraxia battery for adults (2nd ed.). Austin, TX:
Pro-Ed.
Duffy, J. R. (2013). Motor speech disorders: Substrates, differential
diagnosis, and management (3nd ed.). St. Louis: Elsevier Mosby.
Hedge, M. N., & Freed, D. B. (2011). Assessment of
communication disorders in adults. San Diego, CA: Plural
Publishing.
McNeil, M. R., Robin, D. A., & Schmidt, R. A. (2009). Apraxia of
speech: Theory and differential diagnosis. In: M. R. McNeil
(Ed.), Clinical management of sensorimotor speech disorders (2nd
ed.). New York: Thieme.
Wambaugh, J., Duffy, J., McNeil, M., Robin, D., & Rogers, M.
(2006). Treatment guidelines for acquired apraxia of speech: A
synthesis and evaluation of the evidence. Journal of Medical
Speech-Language Pathology, 14(2), xv–xxxiii.
Wambaugh, J. & Mauszycki, S. (2010). Sound
ProductionTreatment: Application with severe apraxia of
speech, Aphasiology, 24:6-8, 814-825