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Acquired Apraxia of Speech

The scope of this page is limited to acquired apraxia of speech. See childhood apraxia of speech for information about speech motor programming disorders in children.

See the Apraxia of Speech (Adults) Evidence Map for summaries of the available research on this topic.

Apraxia of speech (AOS) is a "neurologic speech disorder that reflects an impaired capacity to plan or program sensorimotor commands necessary for directing movements that result in phonetically and prosodically normal speech" (Duffy, 2013, p. 4). AOS has also been referred to in the clinical literature as verbal apraxia or dyspraxia. For the purpose of this page, AOS will refer to acquired apraxia of speech.

AOS frequently co-occurs with dysarthria and/or aphasia and sometimes with limb apraxia, oral apraxia, apraxia of gait, and apraxia of swallowing. AOS does not involve muscle weakness, paralysis, spasticity, or involuntary movements typically associated with dysarthria, or language comprehension or production deficits that characterize aphasia.

There are no reliable data on the incidence and prevalence of AOS in adults. The collection of these data is hindered by challenges associated with the common co-occurrence of AOS with aphasia and dysarthria (Duffy, 2006; Duffy, Strand, & Josephs, 2014) and the difficulty distinguishing among those disorders—particularly in distinguishing between AOS characteristics and phonological errors that can occur in aphasia (McNeil, Pratt, & Fossett, 2004).

McNeil, Robin, and Schmidt (2009) suggest that isolated AOS (i.e., AOS in the absence of dysarthria or aphasia) is very uncommon. Duffy (2013) observed that AOS was documented as the primary, but not necessarily the only, communication disorder for 6.9% of all motor speech disorders in the Mayo Clinic Speech Pathology practice. This percentage would undoubtedly increase drastically if the data included cases in which AOS was a secondary communication disorder (e.g., less severe than aphasia or dysarthria; Duffy, 2013).

The salient features of AOS that have gained broad consensus for differential diagnosis (Ballard, Tourville, & Robin, 2014; Duffy, 2013; McNeil et al., 2009) include

  • reduced overall speech rate;
  • phoneme distortions and distorted substitutions, additions, or complications;
  • syllable segregation with extended intra- and inter-segmental durations; and
  • equal stress across adjacent syllables.

These features are consistent with deficits in the planning and programming of movements for speech and are noted to increase with greater syllable length and motoric complexity.

AOS can improve over time (e.g., in acute stages of stroke recovery, in response to therapy), remain stable, or worsen (e.g., primary progressive apraxia of speech).

Other Perceptual Speech Characteristics

The following other speech characteristics may not be unique to AOS and can also occur with co-existing dysarthria or aphasia.


  • Consonant errors greater than vowel errors
  • Voicing errors (blurred distinctions between boundaries of voiced–voiceless consonants)
  • Prolonged phonemes
  • Telescoping of syllables (e.g., "disaur" instead of "dinosaur")

Rate and Prosody

  • Slow overall rate, regardless of accuracy of productions
  • Alternative motion rates (AMRs) that may be characterized by place or manner errors
  • Poorly sequenced sequential motor rates (SMRs)


  • Disrupted fluency with attempts at self-correction
  • Difficulty initiating articulatory sequences—may be accompanied by audible or silent groping behaviors marking false starts and restarts
  • Sound and syllable repetitions

Other Problems That Can Co-Occur With AOS

Linguistic and nonspeech/non-oromotor features that are observed during clinical presentation typically depend on the site of lesion and comorbid conditions. These include the following:

  • Aphasia—language comprehension and/or production deficits
  • Dysarthria—motor speech disorder characterized by impaired neuromuscular speech movements due to weakness or paralysis, spasticity, incoordination, involuntary movements, or reduced movement range
  • Nonverbal oral apraxia—difficulty programming orofacial musculature for nonspeech movements
  • Apraxia of swallowing—difficulty programming muscles of the head and neck for coordinated swallowing
  • Limb apraxia—difficulty programming purposeful limb movements, often of both extremities
  • Varying degrees of right-sided weakness and spasticity

Acquired AOS is caused by any process or condition that compromises the structures and pathways of the brain responsible for planning and programming motor movements for speech. Causes most often include

  • stroke;
  • traumatic brain injury (TBI);
  • tumor;
  • surgical trauma (e.g., tumor resection); or
  • neurodegenerative diseases (e.g., corticobasal degeneration, progressive supranuclear palsy)

Occasionally, AOS is the first, only, or most prominent symptom in degenerative conditions. The term primary progressive AOS (PPAOS) is used in such cases (Duffy, 2006; Duffy & McNeil, 2008; Duffy, Peach, & Strand, 2007). Premotor and supplementary motor areas are implicated in progressive forms of AOS (e.g., Josephs et al., 2012).

Speech-language pathologists (SLPs) play a central role in the screening, assessment, diagnosis, and treatment of persons with AOS. The professional roles and activities in speech-language pathology include clinical services (diagnosis, assessment, planning, and treatment); prevention and advocacy; and education, administration, and research. See ASHA's Scope of Practice in Speech-Language Pathology (ASHA, 2016).

The following roles are appropriate for SLPs:

  • Providing prevention information to individuals and groups known to be at risk for etiologies (e.g., stroke) associated with AOS, as well as to individuals working with those at risk.
  • Educating other professionals on the needs of persons with AOS and the role that SLPs play in meeting those needs.
  • Screening individuals who present with possible AOS and determining the need for further assessment and/or referral for other services.
  • Conducting a culturally and linguistically relevant comprehensive assessment of speech, language, and communication.
  • Diagnosing the presence of AOS and establishing its severity and prognosis.
  • Using dynamic assessment for differentially diagnosing AOS.
  • Providing intervention to individuals suspected of having AOS.
  • Referring to, and collaborating with, other professionals to determine etiology of AOS and to facilitate access to comprehensive services.
  • Making decisions about the management of AOS.
  • Making decisions, as part of the interdisciplinary team, about eligibility for services based on the presence of AOS and any co-occurring conditions.
  • Developing culturally and linguistically appropriate treatment plans, providing intervention and support services, documenting progress, and determining appropriate service delivery approaches and dismissal criteria.
  • Serving as an integral member of an interdisciplinary team working with individuals with AOS and their families/caregivers.
  • Counseling persons with AOS and their families/caregivers regarding communication-related issues and providing education aimed at preventing further complications related to AOS.
  • Consulting and collaborating with other professionals, families/caregivers, and others to facilitate program development and to provide supervision, evaluation, and/or expert testimony, as appropriate.
  • Remaining informed of research in the area of AOS, helping advance the knowledge base related to the nature and treatment of this disorder, and using evidence-based practice to guide intervention.
  • Advocating for individuals with AOS and their families at the local, state, and national levels.

As indicated in the Code of Ethics (ASHA, 2010r), SLPs who serve this population should be specifically educated and appropriately trained to do so. SLPs who diagnose and treat AOS must possess skills in differential diagnosis of motor speech disorders and co-morbid language disorders; have specialized knowledge in phonological encoding disorders and motor learning theory; and have experience with appropriate intervention techniques.

See the Assessment section of the Apraxia of Speech (Adults) Evidence Map for pertinent scientific evidence, expert opinion, and client/caregiver perspective.


Screening may be conducted by the SLP prior to more comprehensive evaluations, when AOS is suspected secondary to a neurological insult (e.g., stroke).

Screening does not provide a diagnosis or a detailed description of the severity and characteristics of speech deficits associated with AOS but, rather, identifies the need for further assessment. It can be completed using nonstandardized procedures, considering there are no AOS-specific standardized screening tools available to date.

During screening, SLPs also look for signs of co-morbid language, cognitive–communication, and swallowing deficits associated with the neurological insult.

It is best practice to complete a hearing screening to rule out hearing loss that might affect testing. If the individual wears hearing aids, the devices need to be inspected to ensure that they are in working order, and they need to be worn during screening.

Screening may result in recommendations for

  • rescreening;
  • comprehensive assessments; and/or
  • referral for other examinations or services.

Results of screening procedures are interpreted within the context of the individual's cognitive–linguistic and sensory deficits.

Comprehensive Assessment

A comprehensive assessment is conducted for individuals suspected of having AOS using both standardized and nonstandardized measures (see assessment tools, techniques, and data sources).

Consistent with the World Health Organization's (WHO) International Classification of Functioning, Disability and Health (ICF) framework (ASHA, 2007; WHO, 2001), comprehensive assessment of individuals with AOS is conducted to identify and describe

  • impairments in body structure and function, including underlying strengths and weaknesses in speech sound production and verbal/nonverbal communication;
  • co-morbid deficits such as other types of apraxia, aphasia, and dysarthria;
  • the individual's limitations in activity and participation, including functional status in communication, interpersonal interactions, self-care, and learning;
  • contextual (environmental and personal) factors that serve as barriers to, or facilitators of, successful communication and life participation; and
  • the impact of communication impairments on quality of life and functional limitations relative to premorbid social roles and abilities for the individual and the impact on his or her community.

See Person-Centered Focus on Function: Acquired Apraxia of Speech [PDF] for an example of assessment data consistent with ICF.

Comprehensive Assessment for Acquired AOS: Typical Components

Case history

Medical status and history, education, occupation, and cultural and linguistic backgrounds

Self-reported areas of concern

Evaluate functional communication success and the psychosocial impact of the condition on the patient and caregiver, and identify meaningful functional goals for the individual and caregiver(s)

Communication difficulties, contexts of concern (e.g., social interactions, work activities), language(s) used in those contexts, and the individual's goals and preferences

Sensory and motor status

Relevant in identifying nonspeech communication methods for individuals presenting with greater severity

Factors that influence performance on speech assessment tasks

Integrity of speech subsystems

Respiration, phonation, resonance, oral articulatory system (lips, tongue)

Oral–motor mechanisms and nonspeech oral praxis

Used to differentiate AOS from dysarthria and oral apraxia

Strength, speed, and range of movement of components of the oral–motor system

Steadiness, tone, and accuracy of movements for speech and nonspeech tasks (Darley, Aronson, & Brown, 1969)

Perceptual speech characteristics

To identify salient features of the individual's speech that aid in differential diagnosis (e.g., AOS vs. dysarthria, aphasia, and nonaphasic cognitive deficits affecting communication)

Uses standardized and nonstandardized assessments and includes analysis of natural communication samples gathered in different modalities (speaking and reading) and contexts (social, educational, or vocational)

Examines influence of stress and/or fatigue on verbal communication (e.g., influence of physiologic and contextual factors that impact communication success)

Motor speech planning (Duffy, 2013) focused on identifying the threshold of breakdown on a continuum of motor planning demands using a variety of tasks and stimuli

  • Production of stimuli of increasing linguistic complexity—phonemes, syllables, mono/multisyllabic words, and sentences that place varying demands on the speech motor system
    • oral/nasal vs. voiced distinction
    • consonant clusters across syllables vs. within syllables
    • stressed vs. unstressed syllables and words
    • automatic/reactive vs. volitional/propositional speech
    • imitation vs. self-generated responses
  • Contextual speech—to assess integrated functioning of all the speech subsystems

Vowel prolongation (to examine respiratory–phonatory coordination)

Alternating motion rates (AMRs; also called diadochokinetic rates; to judge speed and regularity of movement of articulators)

Sequential motion rates (SMRs; to evaluate ability to move quickly and sequentially from one articulatory posture to another, an impairment that is particularly characteristic of AOS)

Intelligibility (the degree to which the acoustic signal produced by the individual is understood)

Comprehensibility (the degree to which a listener understands the individual based on the acoustic signal plus other linguistic and nonspeech cues)

Efficiency (the rate at which an intelligible or comprehensible utterance is communicated; critical to setting meaningful functional targets in treatment planning)

Acoustic and physiologic assessments using instrumental procedures to quantify abnormalities in voice onset time, rate, prosody and stress, articulation, and trial-to-trial variability

Voice and resonance

Helps differentiate AOS from dysarthria

Abnormal features of voice and resonance (e.g., harsh, breathy, weak voice; hypernasality, hyponasality)


Helps differentiate AOS from aphasia

Expressive and receptive skills

Identification of contextual barriers and facilitators

To determine potential for effective use of compensatory techniques and strategies, including the use of augmentative and alternative communication (AAC)

Facilitators (e.g., ability and willingness to use AAC systems; family support; motivation to return to prior level of function)

Barriers (e.g., reduced confidence in verbal communication; cognitive deficits; visual and motor impairments)

Assessment may result in the following outcomes:

  • Diagnosis of AOS.
  • Clinical description of the characteristics and severity of the disorder.
  • Statement of prognosis and recommendations for intervention that relate to overall communication adequacy, including augmentative or alternative communication (AAC) measures as needed. See ASHA's Practice Portal page on Augmentative and Alternative Communication.
  • Identification of relevant follow-up services for appropriate intervention and support for individuals with AOS.
  • Referral to other professionals as needed, including, for example, the following professionals:
    • Occupational therapist—for nonspeech, sensory–motor, or fine motor issues.
    • Physical therapist—if gross motor skills or overall muscle tone are of concern.
    • Neurologist—if the causal diagnosis is uncertain or if other neurological signs or symptoms are identified that require further investigation or management.

Differential Diagnosis

AOS often co-occurs with or presents similarly to other neurogenic communication disorders such as dysarthria and aphasia. Differential diagnosis between these conditions and AOS is, therefore, an essential part of comprehensive assessment.

Distinguishing AOS From Dysarthria

The dysarthria subtypes that are most difficult to distinguish from AOS are ataxic and unilateral upper motor neuron dysarthria (Duffy, 2013).

Examination of speech subsystems using both speech and sometimes nonspeech tasks is crucial to distinguish between AOS and dysarthria. Differences between AOS and dysarthria include those listed below.

  • AOS can present without muscle weakness, which is often a sign of several dysarthria types.
  • AOS is marked by articulatory and prosodic deficits, unlike dysarthria, in which several speech subsystems can be affected.
  • In contrast to AOS, dysarthric speech may present with more consistent error patterns and is generally not influenced by automaticity of speech production, stimulus modality, and linguistic variables (Duffy, 2013).
  • Other apraxic speech characteristics, such as a larger variety of articulatory errors and groping for articulatory postures, are typically not seen in dysarthria.
  • Poorer performance on SMRs than on AMRs in AOS may distinguish it from ataxic dysarthria (Duffy, 2013).

Distinguishing AOS From Aphasia

AOS is sometimes difficult to differentiate from aphasia in its clinical presentation, given the frequent co-occurrence of these two conditions. In addition, aphasia may be so severe that AOS may be masked during the assessment.

Although the speech sound errors noted on assessment arise from different processing impairments (motor planning deficits in AOS vs. linguistic breakdown in aphasia), the error patterns are often similar, particularly in very mild or very severe presentations. Temporal acoustic characteristics of speech help distinguish between AOS and aphasia better than perceptual characteristics alone (Haley, Jacks, de Riesthal, Abou-Khalil, & Roth, 2012).

The following characteristics can help distinguish between AOS and aphasia (Duffy, 2013):

  • Prosodic abnormalities that characterize AOS are typically absent in aphasia.
  • Multimodal language processing deficits that are typically seen in aphasia are absent in AOS alone.

Assessment Considerations: Progressive Conditions

Periodic reassessment of individuals with AOS is important because neurological recovery can occur for several months or longer, especially in the early phases of recovery. Ongoing assessment can also be used to examine an individual's responses to rehabilitation and to life adaptations after the injury.

Progressive conditions such as PPAOS require periodic reassessment to ensure that the individual is communicating at maximal levels of independence and to plan ahead for additional communication adaptations that may become necessary with disease progression.

Assessment Considerations: Cultural and Linguistic Factors

The SLP considers the influence of cultural and linguistic factors on the individual's communication style and the potential impact of impairment on function when selecting screening and assessment tests. The assessment is conducted in the language(s) used by the person with AOS, with the use of interpretation services as necessary (see collaborating with interpreters).

Appropriate accommodations and modifications can be made to the testing process to reconcile cultural and linguistic variations. Comprehensive documentation includes descriptions of these accommodations and modifications. Scores from standardized tests should be interpreted and reported with caution in these cases.

See the Treatment section of the Apraxia of Speech (Adults) Evidence Map for pertinent scientific evidence, expert opinion, and client/caregiver perspective.

Consistent with the WHO's ICF framework (WHO, 2001), the goal of intervention is to help the individual achieve the highest level of independent function for participation in daily living. Intervention is designed to

  • capitalize on strengths and address weaknesses related to underlying structures and functions that affect communication;
  • facilitate the individual's activities and participation toward the acquisition of new skills and strategies; and
  • modify contextual factors that serve as barriers and enhance those that facilitate successful communication and participation, including development and use of appropriate accommodations.

For individuals with AOS, treatment goals focus on facilitating the efficiency, effectiveness, and naturalness of communication by

  • improving speech production and intelligibility and, when indicated,
  • using augmentative and alternative forms of communication (AAC), such as gestures, manual signs, electronic speech output devices, and context-specific communication boards.

Barriers to successful communication and participation can be minimized for individuals with AOS by

  • modifying the environment (e.g., reducing background noise, maintaining eye contact, and decreasing the distance between speaker and listener);
  • informing listeners about the individual's communication needs and his or her preferred method of communication; and
  • encouraging the speaker to use strategies for repairing breakdowns in communication (e.g., repeating, rephrasing, using gestures, writing).

See Person-Centered Focus on Function: Acquired Apraxia of Speech [PDF] for an example of functional goals consistent with ICF.

Family-Centered Practice

The goal of family-centered practice for individuals with AOS is to create a partnership so that family members fully participate in all aspects of the individual's care. The range of services offered to families includes counseling; providing resources and information; coordinating services; advocating for practices that incorporate family preferences and address family priorities; and teaching specific skills to family members and other significant communication partners. See family-centered practice.

Treatment Considerations

When designing a treatment program for an individual with AOS, consider the following factors:

Target selection

  • Stimulability is often used to determine initial therapy targets; however, more difficult targets may promote better generalization (Ballard, 2001; Maas et al., 2008; Odell, 2002).
  • Words and phrases are motivating and functional; whenever possible, treatment begins with meaningful and self-selected speech stimuli.

Task hierarchy

  • Consistent with the principles of motor learning, practice is hierarchical, and selection of stimulus targets promotes success at each step (Guadagnoli & Lee, 2004).
  • Tasks typically begin at the syllable level—the basic unit of speech programming (Duffy, 2013; Schoor, Aichert, & Ziegler, 2012; Ziegler, Aichert, & Staiger, 2010)—unless the individual has some success at the word or phrase level.
  • Single sounds (phonemes) or nonspeech oral-motor movement patterns that approximate speech gestures (e.g., lip rounding and tongue elevation) might be targeted initially if the individual is not yet capable of meaningful speech (Duffy, 2013), especially when oral apraxia is absent.
Examples of Stimulus and Task Variables That Affect Responses
Easier More difficult
Oral/nasal distinctions Voiced distinctions
Bilabial and lingual/alveolar place of articulation Other places of articulation
Consonant clusters that cross syllables Consonant clusters within syllables
Shorter syllables Longer syllables
High frequency syllables and words Low frequency syllables and words
Stressed syllables and words Unstressed syllables and words
Automatic/reactive speech Volitional/propositional speech
Imitation of a model Self-generation of response (especially in those with co-existing aphasia)
(Duffy, 2013)
  • For individuals who are nonverbal, reflexive actions (e.g., cough, laugh) may be initially elicited as reflexes and then shaped to volitional control and ultimately to voluntary speech production (Simpson & Clark, 1989).


  • Learning may be enhanced when feedback is intermittent rather than constant (e.g., 60 % of the time) or when there is a delay (e.g., 5 seconds) between response and feedback (Austermann Hula, Robin, Maas, Ballard, & Schmidt, 2008).
  • Self-monitoring and self-correction can facilitate learning and maintenance of skills (Rosenbek, Lemme, Ahern, Harris, & Wertz, 1973).

Treatment Approaches

Treatment can be restorative (i.e., aimed at improving or restoring impaired function) and/or compensatory (i.e., aimed at compensating for deficits not amenable to retraining).

Approaches aimed at improving speech production and intelligibility focus on re-establishing motor plans/programs and improving the ability to select and activate them and set program parameters (e.g., speed) in specific situations (Knock, Ballard, Robin, & Schmidt, 2000). These treatment approaches include articulatory–kinematic approaches, sensory cueing, rate and/or rhythm control, and various combinations thereof.

Augmentative and alternative communication (AAC) approaches are used to provide functional communication options, while at the same time, supporting, enhancing, and potentially improving speech production (Lasker, Stierwalt, Hageman, & LaPointe, 2008; Yorkston, Beukelman, Strand, & Hakel, 2010).

From the perspective of the WHO's ICF framework (WHO, 2001), approaches aimed at improving speech production and intelligibility focus on "body functions/structures" within the ICF framework, whereas AAC approaches are directed at "activities/participation."

Treatment Options

Below are brief descriptions of treatment options for addressing AOS, grouped by approach. This list is not exhaustive, and the inclusion of any specific treatment does not imply endorsement from ASHA. See Ballard et al. (2015) and Wambaugh, Duffy, McNeil, Robin, and Rogers (2006) for systematic reviews of AOS interventions.

Treatment selection depends on a number of factors, including severity of the disorder, communication needs of the individual, and presence and severity of co-occurring conditions (e.g., aphasia and associated language and cognitive deficits, dysarthria, or progressive neurological diseases).

Apraxia in other systems may play a role in treatment. For example, the presence of limb apraxia may preclude using manual signs to support functional communication. The presence of oral apraxia may support the need for more aggressive or alternative approaches to the use of phonetic placement cues in speech treatment.

Articulatory–Kinematic Approaches

Articulatory–kinematic approaches are based on principles of motor programming/planning. They

  • provide frequent and intensive practice of speech targets;
  • focus on accurate speech movement;
  • include external sensory input for speech production (e.g., auditory, visual, tactile, cognitive cues);
  • consider practice schedules, such as random versus blocked practice (see, e.g., Wambaugh, Nessler, Wright, & Mauszycki, 2014; Wambaugh, Nessler, Wright, Mauszycki, & DeLong, in press); and
  • provide appropriate types and schedules of feedback regarding performance.

See Bislick, Weir, Spencer, Kendall, and Yorkston, 2012 and Maas et al. (2008) for discussions of motor learning principles as they apply to the treatment of motor speech disorders.

Multiple Input Phoneme Therapy (MIPT)

MIPT is appropriate for individuals with severe apraxia of speech. The program proceeds through a hierarchy of steps that stress phoneme generalization using multiple input stimuli. The individual's stereotypic utterances are used as initial stimuli; the clinician models these utterances while simultaneously providing a gestural/prosodic cue (e.g., tapping the individual's arm). The clinician then fades the voice and mimes the movement while the individual continues to produce the target. New words use the initial phoneme of a stereotypic utterance (e.g., "one" to "win"). The number of targets and the length and phoneme complexity progressively increase. The individual initially repeats the stereotypic utterance in a nonvolitional manner and eventually regains volitional control and the ability to spontaneously express words and phrases (Stevens, 1989; Stevens & Glaser, 1983).

Script Training

Script training is a functional approach to treating neurogenic communication disorders (Holland, Milman, Munoz, & Bays, 2002). It is used to facilitate verbal communication on specific topics selected by the individual. Script training helps the individual who wants to speak relatively normally on a few personally relevant topics. A number of phrases are practiced so that they become automatic and can be inserted into conversation relatively fluently (Youmans, Youmans, & Hancock, 2011).

Sound Production Treatment (SPT)

SPT is used to improve production of consonants that are problematic for a particular speaker. It uses a treatment hierarchy that incorporates modeling and repetition of minimal-contrast word pairs. Auditory, visual and tactile cues are used, along with articulatory placement cueing and graphemic cues (Wambaugh, Kalinyak-Fliszar, West, & Doyle, 1998; Wambaugh & Mauszycki, 2010).

Speech Motor Learning (SML) Approach

The SML treatment approach addresses the underlying inability to plan and program the production of speech motor targets (SMTs) in varying phonetic contexts and in utterances longer than single words or nonwords. Nonwords, constructed from a corpus of target consonants and vowels, are used as treatment stimuli. Treatment proceeds in steps, taking the individual from imitated blocked practice of each nonword to self-initiated production of a series of nonwords. Eventually, real words and phrases containing these words are identified and rehearsed until the criterion is met (Van der Merwe, 2011).

Sensory Cueing Approaches

Many treatments for AOS incorporate sensory input (e.g., visual, auditory, proprioceptive, and tactile cues) to teach the movement sequences for speech. Sensory cues can be used separately or in combination (i.e., multisensory approach). Feedback is an important aspect of motor learning. These external cues may facilitate speech production by providing additional feedback to the individual if he or she cannot benefit from, or does not receive, sufficient intrinsic sensory feedback.

Integral Stimulation (IS)

IS is part of many treatment approaches. It is a method for practicing movement gestures for speech production that involves imitation and emphasizes multiple sensory models (e.g., auditory, visual, tactile). Treatment follows a "listen to me, watch me, do what I do" sequence, in which the individual hears and sees how the clinician produces a targeted sound sequence or word/phrase and then imitates (Rosenbek et al., 1973).

Tactile Cueing

Tactile cueing methods of speech facilitation are those that provide direct tactile input for correct speech production. Using these methods, the SLP applies pressure or otherwise touches the individual's face, neck, and head to provide a tactile cue for correct production or speech movement gesture.

Prompts for Restructuring Oral Muscular Phonetic Targets (PROMPT)

PROMPT is a tactile method of treatment based on touch pressure, kinesthetic, and proprioceptive cues (Bose, Square, Schlosser, & van Lieshout, 2001; Chumpelik, 1984; Freed, Marshall, & Frazier, 1997). Using this approach, the clinician uses finger placements on the individual's face and neck to cue various aspects of speech production (e.g., place and manner of articulation) and help the individual limit unnecessary movements. PROMPT requires specialized training.

Visual Cueing

Visual cueing methods provide visual "cues" as to the shape, placement, or movement of the articulators. Visual cues can be provided via "low-tech" methods (e.g., simple hand signs or visual feedback via a mirror) or more technologically advanced methods that utilize computer software and screen, ultrasound images, and other forms of biofeedback, such as acoustic/spectrographic feedback displays.

Electropalatography (EPG)

EPG utilizes a palatal device with electrodes to record and visualize contact of the tongue on the palate while an individual makes different speech sounds (Howard & Varley, 1995). EPG provides real-time visual feedback as well as a split-screen option so that the SLP can model the correct tongue placement while the patient observes.

Electromagnetic Articulography (EMA)

EMA uses miniature receiver coils placed on and in the mouth (e.g., tongue dorsum, corners of mouth, or velar margin) to record and provide a visual display of tongue, mouth, palate, and jaw movements during treatment. AOS treatment research involving EMA has focused on tongue placement (see, e.g., Katz, Bharadwaj, & Carstens, 1999; Katz, McNeil, & Garst, 2010).

Rate and Rhythm Control Approaches

Rate and rhythm control approaches (also called prosodic facilitation approaches) use intonation patterns (melody, rhythm, and stress) to improve speech production. Although these approaches are aimed at improving prosody, they have also resulted in improved articulation for individuals with AOS (Mauszycki & Wambaugh, 2011). Using these patterns, the clinician guides the individual through a gradual progression of steps that increase the length of utterances, decrease dependence on the clinician, and decrease reliance on intonation (Martin, Kubitz, & Maher, 2001).

Contrastive Stress

Contrastive stress is used when speaking to highlight a particular word in a phrase or sentence; varying the stressed word also changes the meaning of the sentence. In treating AOS, contrastive stress can be used in target phrases or sentences to improve the individual's ability to produce speech with varying intonation contours (Wertz, LaPointe, & Rosenbek, 1984).

Melodic Intonation Therapy (MIT)

MIT is a prosodic facilitation approach that uses melody, rhythm, and stress to facilitate speech production. The clinician provides models of intoned utterances of varying lengths; reliance on intonation is gradually decreased over time. MIT was first designed for individuals with nonfluent aphasia, many of whom have co-occurring apraxia of speech (Sparks, Helm, & Albert, 1974; Sparks & Holland, 1976; Zumbansen, Peretz, & Hébert, 2014).

Metrical Pacing Treatment (MPT)

MPT is a type of pacing technique that uses rhythmical sequences of tones that provide metrical templates to guide production of target utterances. Individuals are asked to produce the target utterances in synchrony with the pacing signals. The synchronization pulse is generated by a computer and can be varied by rate (corresponding to speech rate) and metrical structure (syllable number and stress pattern) to simulate the natural stress patterns of speech (Brendel & Ziegler, 2008).

Rhythmic Pacing

Rhythmic pacing strategies use various rate control techniques to provide temporal cues that help pace speech production. Techniques include hand or finger tapping and use of a pacing board or metronome (Dworkin, Abkarian, & Johns, 1988; Mauszycki & Wambaugh, 2008).

Transcranial Direct Current Stimulation (tDCS)

tDCS is an experimental procedure in which transcranial direct current is delivered to the left inferior frontal gyrus (IFG) to modulate cortical activity. It has been used in conjunction with articulatory–kinematic treatment to improve the speech of individuals with AOS secondary to stroke. Speech targets consist of syllables and words that are presented auditorily and are repeated by the individual (Marangolo et al., 2011).

Augmentative and Alternative Communication (AAC)

AAC involves supplementing or replacing natural speech or writing with aided symbols (e.g., picture communication, line drawings, speech-generating devices, and tangible objects) or unaided symbols (e.g., manual signs, gestures, and finger spelling). Whereas aided symbols require some type of transmission device, the production of unaided symbols requires only body movements. When selecting AAC systems or devices, it is important to determine the individual's willingness to use them. See Lasker and Bedrosian (2001) for a discussion on promoting acceptance of AAC by adults with acquired communication disorders. See ASHA's Practice Portal page on Augmentative and Alternative Communication for additional information.

Treatment Considerations: Factors Influencing Treatment Decisions

Not all individuals with AOS are candidates for treatment. For example, the language impairments associated with aphasia can affect both comprehension and expression so severely that functional communication (verbal or alternative/augmentative) is not possible. In such cases, clinicians might first focus on improving basic language and cognitive abilities to support functional communication. If language and cognitive abilities do not improve sufficiently, AOS treatment would not be appropriate (Freed, 2012).

Treatment for individuals with AOS resulting from degenerative disease is often appropriate, particularly for those with no significant language or cognitive impairments. The goal of treatment is to maximize communication at each stage of the disease, not to reverse decline (Duffy, 2013). Goals in the early stages might begin with efforts to improve speech and maintain comprehensibility, followed by establishing the use of compensatory strategies, including AAC (Duffy & McNeil, 2008; Jung, Duffy, & Josephs, 2013).

Treatment Considerations: Adults With Previously Or Newly Diagnosed Childhood Apraxia Of Speech (CAS)

Some adults were diagnosed with CAS as children, but, despite having had treatment, their speech difficulties persist. Others have had long-standing speech difficulties that are only now being diagnosed as apraxia. Adults with previously or newly diagnosed CAS often seek services because their speech difficulties are having an impact on communication in school, work, or social settings. The treatment principles and at least some of the options described above may be appropriate for these individuals. Goals focus on the individual's specific communication needs (e.g., in the classroom, at work, or in social situations). See childhood apraxia of speech for more detailed information about CAS.

Service Delivery

In addition to determining the optimal speech and language treatment for an individual with AOS, the clinician considers other service delivery variables that may have an impact on treatment outcomes, such as format, provider, dosage, timing, and setting.


Format refers to the structure of the treatment session (e.g., group and/or individual). The appropriateness of treatment format (individual vs. group vs. both) depends on the primary goal at a particular point in the treatment process. For example, initial treatment may involve intensive drills to improve speech production and/or practice in using AAC aids. However, once the individual has made progress on these goals, group treatment may be incorporated to provide opportunities for practice.


Provider refers to the person providing the treatment (e.g., SLP, trained volunteer, caregiver). SLPs treat the speech-motor and communication aspects of AOS and train individuals in the use of AAC. It is important to involve family members, caregivers, and other communication partners in the treatment process to help them understand the individual's communication needs and learn strategies to facilitate communication. Other professionals (e.g., physical therapist or occupational therapist) may be involved in treatment of co-morbid deficits. It is important for SLPs to collaborate with other professionals regarding treatment and to take advantage of opportunities for co-treatment.


Dosage refers to the frequency, intensity, and duration of service. Treatment dosage for AOS should be consistent with principles of motor learning (Maas et al., 2008; Rosenbek et al., 1973; Wambaugh et al., 2014). Given the need for repetitive production practice in motor speech disorders like AOS, intensive and individualized treatment is often stressed. See Ballard et al., 2015, for a discussion of average dosage.


Timing refers to the timing of intervention relative to diagnosis. Generally speaking, treatment begins as early as possible post onset. Treatment can also be appropriate when an extended amount of time has elapsed since onset, particularly if an individual has not received any treatment for AOS during that time. Treatment can be effective for individuals in the chronic phase of AOS, based on data from AOS treatment studies and supporting data from stroke literature suggesting that recovery of stroke-related deficits can occur during this phase (Wheaton, 2015).


Setting refers to the location of treatment (e.g., home, community-based). A naturalistic treatment environment that incorporates a variety of communication partners may facilitate generalization and carryover of skills.

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Content for ASHA's Practice Portal is developed through a comprehensive process that includes multiple rounds of subject matter expert input and review. ASHA extends its gratitude to the following subject matter experts who were involved in the development of the Acquired Apraxia of Speech page:

  • Kirrie J. Ballard, PhD, CCC-SLP
  • Heather M. Clark, PhD, CCC-SLP
  • Shannon Cook Mauszycki, PhD, CCC-SLP
  • Joseph R. Duffy, PhD, CCC-SLP
  • Katarina Haley, PhD, CCC-SLP
  • Edwin Maas, PhD
  • Malcolm R. McNeil, PhD, CCC-SLP
  • Christina Nessler, MS, CCC-SLP
  • Edythe A. Strand, PhD, CCC-SLP
  • Darlene S. Williamson, MA, CCC-SLP

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