What are Motor Speech Deficits?

Acquired motor speech deficits may occur after a stroke, tumor, brain injury, or other neurological damage. These deficits result in difficulty with planning and performing speech movements. These deficits usually result in difficulty speaking. There are two different potential disorders in this area; dysarthria and apraxia of speech.


Dysarthria results from impaired movement of the muscles used for speech production, including the lips, tongue, vocal folds, and/or diaphragm. The type and severity of dysarthria depend on which area of the nervous system is affected.

A person with dysarthria may exhibit one or more of the following speech characteristics:

  • "Slurred," "choppy," or "mumbled" speech that may be difficult to understand
  • Slow rate of speech
  • Rapid rate of speech with a "mumbling" quality
  • Limited tongue, lip, and jaw movement
  • Abnormal pitch and rhythm when speaking
  • Changes in voice quality, such as hoarse or breathy voice or speech that sounds "nasal" or "stuffy"

Apraxia of Speech

Apraxia of speech (AOS) is a neurologic speech disorder that reflects an impaired capacity to plan or program commands in the brain necessary for directing muscles for speech movements. Individuals with apraxia of speech know what words they want to say, but their brains have difficulty coordinating the muscle movements necessary to say all the sounds in the words. As a result, they may say something completely different or make up words (e.g., "bipem" or "chicken" for “kitchen"). The person may recognize the error and try again—sometimes getting it right, but sometimes saying something else entirely. This situation can become quite frustrating for the person.

A person with apraxia of speech my exhibit one or more of the following speech characteristics:

  • Difficulty imitating and producing speech sounds, marked by speech errors such as sound distortions, substitutions, and/or omissions;
  • Inconsistent speech errors
  • Groping of the tongue and lips to make specific sounds and words;
  • Slow speech rate
  • Impaired rhythm andprosody(intonation) of speech
  • Better automatic speech (e.g., greetings) than purposeful speech
  • Inability to produce any sound at all in severe cases.

Assessment and Treatment

Assessment of motor speech deficits includes the use of standardized tests or informal evaluation along with client interview. This identifies strengths and weaknesses along with outlining areas for treatment. Treatment then works to address impairments and provide strategies to support areas impacted. The focus is on functional outcomes, making an impact in quality of life and helping clients return to activities they love.

Associated Faculty

Jacqueline Daniels, MA, CCC-SLP - Lecturer and Supervisor; Neuro Unit Coordinator
Leslie Kot, MS, CCC-SLP - Lecturer and Supervisor
Mike Burns, PhD, CCC-SLP - Senior Lecturer and Supervisor; Researcher
Kelsey Leighton, MS, CCC-SLP - Lecturer and Supervisor
Shaye Kawashima, MS, CCC-SLP - Lecturer and Supervisor
Kristie Spencer, PhD, CCC-SLP - Professor and Associate Chair; Researcher

Additional Resources

American Speech-Language-Hearing Association

The Mayo Clinic