Medical Speech Pathology

Curiosity, Dialogue, and Knowledge

Assessment of Dysarthria

Always remember when you’re doing a standard OP exam:

Primary thing you’re evaluating is function- are those cranial nerves that support the oral movements normal?

You’re evaluating cranial nerve function.

Facial symmetry.

Good adequate phonation.

Very often the 1st place that neurologic disease presents itself, is through speech problems in a great many cases.

So take the OP exam seriously even with normal adults.  It can be an early sign of something serious lurking.

When assessing, consider:

  • Prosody
  • Resonance
  • Articulation
  • Phonation
  • Respiration

The most common test for dysarthria is called the Frenchay.

More qualitative than quantitative.

Presents problems in reliability, which is really important in tests and assessments.

The largest reliability problem is inter-judge reliability, means how close will two or more clinicians judge the same client, are the results similar and how similar.

The more similar they are the higher the reliability, which is easy to do on quantitative but less easy on a qualitative.

In-experienced judges – tend to do one of 3 things: 1. Tend to judge too high, 2. Too low 3. Take the safe ground and go as close to the center as they can.

In order to make this as reliable as possible, make the judging criteria very clear and as quantitatively based as possible.

It has perfectly acceptable inter reliability and makes it easier for new clinicians who haven’t had a lot of experience administering the Frenchay.

Reflex – cough, swallow, drool, lips at rest, spread, seal, alternated, in speech, jaw at rest, etc, look at test protocol

Normal function is between B and A. You can also score in between if it’s in the middle.

C is abnormal, D and E is no function (like flaccidity, can’t do anything of these things with the lip like bilateral facial palsy).

Tasks: observe drink cold glass of water and a cookie ask about swallowing, score 4-15 seconds with an average of 8 is normal, longer than 8 sec.

Take a breath through the mouth and let out slowly not phonating but audible, score the second attempt, normally 5 sec air should be expelled slowly and smoothly.

Want to do whatever you can to take hypernasality out of the equation.

Ask patient to say may pay, nay bay – looking for hyper nasality and/or unbalanced nasal resonance which you will hear on p and b or noticeable nasal emission.


Say “Ah” as long as possible, score second attempt.

Just count quality in the phonation of “ah”, not when they are forcing out air.

Someone who has weak adduction of the medial edges of the folds will have problems with volume from the get go.

You are asking them to increase the tightness of adduction in a very controlled manner.


Really important ( larynx is really important too).

Neurological deficit with tongue and larynx are really going to cause artic problems.

Observe tongue at rest for at least a min, because the tongue may not go to rest completely right after the mouth is open, a period of time should lapse before observation is made.

Use a tongue blade/depressor.


5 complete movements, score second time.

Tongue in speech – hard to observe.

Vowel distortion indicates a very severe problems, they are relatively open sounds, if you can’t get the tongue in the correct position for vowel you have very seriously impaired movements.

  • Could use it to differentiate one dysarthria from another but don’t recommend it.
  • Hospital setting – order might look like this r/o fl dys CN VI L, rule out flaccid dysarthria cranial nerve VI on left, mean this is all that’s left, other than this you will have a diagnosis of which kind of dysarthria.
  • Using the frenchay, what are the effects of that diagnosis on the aspects of the speech mechanisms?
  • Acts as a good baseline measuring order to show progress especially to insurance companies, easiest way to show progress is to start with baseline.
  • Will tell you how the dysarthria has affected the speech mechanism.
  • We also need to know how that dysarthria has affected their intelligibility because the ultimate treatment goal is compensated intelligibility.
  • In order for this to occur you need a baseline of that information before treatment begins.
  • You are able to measure quantitatively how your therapy has improved their intelligibility with the Assessment of Intelligibility of Dysarthric Speech.
  • Its primary goal or purpose is to measure intelligibility, as a function of severity.

Assessment of Intelligibility of Dysarthric Speech:

Can be used as many times as you want without having the client use the same stimulus tasks.

They will never have the same stimuli on any of the retests.

You are able to obtain the following information:

Single word intelligibility 

Can be evaluated by a judge (not you) 2 different ways:

1st by having the judge write down the words that he or she hears the client say; this is the preferred way if you have a client with a fairly mild dysarthria (mild to moderate), then you record the percentage that the judge correctly wrote down.

2nd (more moderate – severe dysarthria) You will ask the judge to circle from a multiple choice format the word that he or she thinks they heard the client say, then from this take the percentage correct.

Intelligibility of sentences

Always done by having the judge write the whole sentence.

Sentence intelligibility is also evaluated by intelligibility as the function of the length of the sentence.

The percentage correct is the total number of correctly transcribed words, you need to evaluate how the length of the sentence affected intelligibility – this is not a part of the test but good information for you to obtain from the test.

Regardless of the severity of the dysarthria, single word intelligibility is always less than sentence intelligibility. Sentences provide context, syntactic, semantic context – which means the judge or any listener is able to fill in what they might not be able to understand just from the context of the sentence, single words have no context.

People with dysarthria tend to distort sounds and without context it can be difficult to determine what single word was spoken so scores of 45% correct on single words and 65% on sentences are not unusual; it is expected because of the context.

In addition to “words correct in sentences” intelligibility, you can also determine the client speaking rate in words per/min.

Often times you will need to slow the client down because they are trying to talk at the same rate they did before the incident.

You can also determine the rate of intelligible speech in words/min.

You can also determine the communication efficiency ratio.

Judging the Sample

You must tape record the testing.

You do not want someone who is familiar with the client, you want a judge that is unfamiliar and has never talked to them, can be another clinician, not the husband, boyfriend, etc.

You administer 50 single words while you tape record.

When you tape record, you can count, number 1, and point to the circled word for the client to read, then pause so the judge has time to process and judge what they think.

What if they can’t read, double vision etc. then what do you do?

Don’t hit stop, hit pause on your recorder because it makes a click on the recording.

Try and make sure there is no other background noise.

All are similar sounding so hopefully the scores aren’t effected.

On the other hand if they have a moderate to severe aphasia – you hand them a blank score sheet and have them circle what they heard.

Sentence task – you have random numbers.

Starts with 5 word sentences, record the client as they read the 2 sentences.

Point to the sentence and have them read it.

Allow enough time for the judge to have enough time to write down the sentence that they hear the client say.

One chance, cannot replay it again.

Do the same thing with 6 word sentences – all the way to 15 word sentences (reading 2 of each).

Now this can present certain problems, if the client is a poor reader or illiterate, then you have to read the sentence to the client, and then have the client repeat what they hear.

What if they don’t have a good memory? How can you expect them to remember a 15 word sentence perfectly? They won’t, so if you have to read it to them they won’t be able to do all the way to 15 word sentences.  So be it, if a 5 word sentence can consistently be remembered, then do a bunch of 5 word sentences and make a note in the report that this part of the test had to be adapted; it’s fine because it isn’t a normed test, you can still do all the rest of the calculations with 10 or 20 word sentences, but if they are ok to read, you do 2 of every sentence length.

The judges score will be higher on sentences.

Percent correct: divide total words by # correctly written by the judge.

# correct/ total

This will give you the intelligibility score at present.

Speaking rate + total # of words/ speaking time in min. Common mistake, when you have the stop watch, you are only measuring time when they are speaking, minor hesitations is fine to count, don’t count the time in between sentences.

Rate of intelligible speech is the # of words correctly written down by the judge/duration (you already have this because you have already computed words per min. then you get the percentage of intelligible words per/min.  This is very valuable, especially if you need to slow down the clients speech.

Once they are speaking at a slower rate, you want to see if their intelligibility is better next time you administer the AIDS.

Efficiency ratio is the intelligible words /min score divided by 190. 190 is the average intelligible speech per min of normal speakers, the further it is away from 1.00 the further their intelligibility is from a normal speaker, the closer it is to 1.00 the closer their intelligibility resembles a normal speaker.

You want to see an increase in the communication efficiency ratio – you want to see it increase as close to 1.0 as possible.

This gives you baseline info that is invaluable to you, most people balk at figuring speaking rate in words per min, but it’s not hard and it is worth it!

6 comments on “Assessment of Dysarthria

  1. Jordon
    October 4, 2012

    Thank you for posting this information! It has been very helpful to have as a reference to the methods of AIDS.

  2. organizednowplease
    May 9, 2013

    Love the intelligibility ideas. It would be great for progress monitoring for articulation kids too.

  3. SLP2BnDC
    April 1, 2015

    thank you so much! as a current SLP graduate student, these tidbits are extremely helpful.

    • Admin
      April 1, 2015

      Thanks for visiting the site. Feedback and *ahem* any additions to the site will continue to make this a thriving community.

  4. Amelia Parker
    October 6, 2016

    This article was very helpful, but what if the patient is totally unintelligible? Only vowels were a and I. This client is two years s/please CVA with severe oropharyngeal deficits. Do I just look at word approximations or assess syllable productions? She mainly had grunts but could not produce k, g, or h.

  5. Chronically20Something
    June 4, 2017

    Writing my first exam on motor speech disorders & their Ax tomorrow and really appreciated this post!

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