treating speech-sound problems: articulatory, perceptual, or phonological intervention

PETER FLIPSEN JR., PH.D., CCC-SLPIDAHO STATE UNIVERSITY

[email protected]

HTTP://WWW.ISU.EDU/~FLIPPETE/DEFAULT.HTML

Treating Speech-Sound Problems:

Articulatory, Perceptual, or Phonological Intervention

IMASH 2008 - Salt Lake City, UT

Are all speech sound problems the same?

For children whose problems have an obvious cause we can usually predict the error types. Also often know what treatment works.

For children with “unknown” etiologies, we are not so sure. They don’t all exhibit the same error patterns. They don’t all respond the same to therapy. Even within the same child, we may need to use

different approaches for different targets.


A Quick Historical Review

Up until the mid 1970s we assumed speech sound problems were all about “articulation”. Treatment focused on ‘how to physically make the

sounds’.

Then we learned about “phonology” and we realized children were learning a “sound system”. Assessment shifted to looking for ‘patterns of errors’

(also called “processes”). Treatment shifted to ‘contrasts’ and ‘meaning’ and

‘minimal pairs’.


What about perception?

Traditional views of “articulation disorders”: These children must not be hearing the differences

among some of the sounds.

Studies failed to show consistent patterns of misperception. No general perceptual difficulties. Most children can discriminate their errors from what

they should be saying. Still possible for some errors to be due to problems of

perception.


Current Status: Some “shaky” assumptions

1. We don’t need to worry about perceptual errors. No. Even though these are not that common we

should check.

2. We can assume that the child with many errors must have a phonological problem. No. Child could have a “motor learning” problem.

3. We can assume that the child with few errors must have an articulatory problem. No. Child may not have figured out where that sound

fits in the system.


More “shaky” assumptions

4. Calling the error a “phonological process” means the problem must be phonological. No. By themselves these labels tell us NOTHING

about what is going on inside the child’s head. Saying that a child exhibits “velar fronting” tells us no

more than that velar sounds are being replaced by sounds further forward in the mouth.

It doesn’t tell us why!


Phonological Processes?

Phonological process terms can be useful.They do help us look for WHAT MIGHT BE

systematic patterns of errors. They can help us focus our intervention efforts if we

do eventually determine the nature of the problem.

BUT without further detailed analysis, we can’t know for certain whether the problem is articulatory or phonological.


More “shaky” assumptions.

5. We can assume that if a sound is stimulable, the problem must be phonological. Not necessarily, though it might be. Stimulability in isolation or nonsense syllables may

only signal some degree of motor readiness or the beginnings of motor skill learning.

Stimulability in more than one word position at the word level makes it more likely that the problem is phonological.

Also depends on how stimulability is measured. Should use a verbal imitation model only. Testing task, not a teaching moment.


How Speech is Learned

Need to be able to hear the differences among the speech sounds of the language. Perceptual skills.

Need to be able to physically produce the sounds. Articulatory (motor) skills.

Need to know how the sounds are used to contrast meaning in the language. Phonological knowledge.

Happens gradually and at different rates for different sounds.


Speech Sound Problems

Could be perceptual.Could be articulatory.Could be phonological.

And because of different rates of development:THE PROBLEM MAY BE DIFFERENT FOR

DIFFERENT SPEECH SOUNDS – even within the same child. Suggests we need to evaluate each error independently.


Identifying Perceptual Problems

At least two ways to do this:1. Same/different tasks – present a pair of

words (or syllables or sounds) and ask child to judge if they are the same or different. Child must understand the concepts of ‘same’ and

‘different’ not always true for very young children.

Only requires the child to hold items in working memory and compare them. Doesn’t get at ‘underlying representation’ (what they

have stored in long-term memory about the sounds).



2. Judgment tasks – present child with a word (correct production or containing their usual error). Child has to decide if the word was produced correctly. Requires use of working memory BUT also requires

them to compare what they heard to their underlying representation.

Better approach.



Need several examples to control for guessing.

Need a way to ensure that the child understands the task. Use a sound that is similar to the error sound but

which the child has no difficulty with.

Locke (1980) developed his “Speech Production – Perception Task” (SP-PT). Allows you to create a unique criterion-referenced test

for each sound the child has in error.


Is the error articulatory or phonological?

Relatively few errors are perceptual BUT: Should still check. May save considerable time later. Some evidence that for SOME children working on

perception alone may solve the problem.

The big problem is separating articulatory and phonological errors. Need to ask a series of questions (none sufficient alone).

1. Stimulability – across word positions and levels. Discussed previously.


Articulatory or Phonological?

2. Is the sound ever correct?If correct in particular words:

May just be an over-learned word (doesn’t tell us much).

If correct in particular word positions: May be articulatory problem.

May not have learned the co-articulatory aspects in particular word positions.

May be phonological problem. May not have figured out that the sound can be used in

more than one position.



3. Does the sound ever appear accidentally?Is the sound ever used as a substitute for

something else. E.g., /c/ never correct but used in place of /s/. Suggests child is capable of producing /c/. But could just be an over-learned word.

If never used accidentally: Sound likely not in inventory suggesting a

phonological problem. But may simply be a failure to learn to physically

produce it.



4. Is contrast between target and substitution being “marked” in some other way?

Narrow transcription may reveal subtle differences: E.g., t/s substitution (stopping error).

Have them produce minimal pairs: nice/night. Listen for a difference in final /s/. May produce /ne]t(/ /ne]t)/ May be marking the difference using aspiration vs. no

aspiration rather than fricative vs. stop.


Marking?

With omission errors, look for evidence that the child at least knows that the missing sound is supposed to be there. Some limitation may be preventing them from actually

producing it.

E.g., omits final /b/. Have them produce mob/mop. Listen for differences in vowel length.


No One Question Provides all the Answers

Led to the development of the decision tree. Still a work in progress.

Can use data from an artic test or transcription of connected speech.

Look at each error and decide on the nature of the intervention needed for that sound.

Treat each sound depending on what the problem is.

With multiple errors of the same type, look for patterns. May be able to treat some of the errors and see

generalization to other related errors.



Which Treatment Approach to Use? Peter Flipsen Jr., Ph.D., CCC-SLP July, 2008 Idaho State University The following decision tree can help you decide which treatment approach to use. This process would follow general data gathering (articulation test, conversational speech sampling) and minimal pair probing to look at whether or not contrasts are being maintained. No Yes No Yes No Yes Yes ------------------------ (if not tested previously)

No (maybe later)

---------------------------------- * if inventory is very limited, consider CAS.

Correct in only some positions Never Correct

Positional Constraint Any accidental occurrence ? Inventory Constraint *

Contrast is marked ? Stimulable to word level in 2-3 word positions ?

Discrimination OK ? Phonemic Error Phonetic Error

Perceptual Training Phonetic Approach Phonemic Approach

Perceptual Therapy?

Traditional ear training?Focused auditory stimulation?

Developed by Barbara Hodson Intended for very young children who may not be

ready for the structure of production practice.

Speech Assessment and Interactive Learning Softward (SAILS) program? http://www.avaaz.com



Phonetic vs. Phonemic Therapy

Yes they are different – or at least they should be!

Not necessarily mutually exclusive however: For errors that are phonetically-based, phonetic

therapy may need to be followed by phonemic therapy. Difference between the two approaches is mostly on

how we organize the targets and how we decide to progress.

When you practice function you are also practicing form and (once you get to the word level) the reverse is true.


Phonetic Therapy

Also called articulation or articulatory therapy. Teaching the physical aspects of producing the sound.

Conventional series of steps: Teach production of the sound in isolation; progress to

production in syllables, words, phrases etc.


Phonemic Therapy

Also called a cognitive-linguistic or phonological approach.

Focuses on teaching the child the function of the sound. Change in sound = change in meaning.

Contrasts = central to the process.


Phonemic Therapy: Principles

1. Treating a pattern of errors – child has not fully learned the sound system.

If using an articulation test as the data source, you will need to transcribe the entire target word to see the larger error pattern(s).



2. Child is usually not producing contrasts between sounds as adults do.

Need to teach the appropriate contrast.Focus on how different sounds result in

different meaning.


Loss of Contrasts: Homonymy

When contrasts are lost, words that are normally different become homonyms (they sound the same).

E.g., Child who uses stops for fricatives: /tu/ for both “shoe” and “two”. /b4t/ for both “but” and “bus”. /pl3]t/ for both “place” and “plate”.



3. Use Naturalistic contexts. Usually work with real words in meaningful contexts. Very helpful to have several "exemplars" of each

target (e.g., several different "dogs").



4. Shouldn't need to work on all possible targets.

Select targets that represent the error pattern.

Assume that a rule will be learned and carryover to the other targets will occur automatically (though it may not in every case).


Target Selection

Selecting targets for phonemic therapy begins with describing the errors.

Need to look for patterns. At least two ways to do this: 1. Natural phonological processes. 2. Look for phoneme “collapses” (homonymy).


Target Selection

With natural processes the targets would be the correct productions. Contrast correct form with what the child usually

does.

For example: Cluster reduction: “stop” vs. “top” Stopping: “sea” vs. “tea” Velar fronting: “kite” vs. “tight”


Target Selection

With phoneme collapses, the first step is to look for what contrasts are lost.

For example, a child produces the following errors: To/Sue, to/shoe, tea/key

At least four phonemes have been collapsed into one.


Target Selection

With phoneme collapses a second step is necessary.

We need to decide how to present the contrast:

1. Minimal contrast – present target and contrasting words that differ by the fewest features (e.g., place or manner only). Teaching a new sound but don’t necessarily contrast it

with the child’s error.


Minimal Contrast

Usually only present one contrast at a time. E.g., only present t/k (place difference) or only present

t/s (manner difference).

Based on the idea of making the difference between the target and the error as small as possible so there is nothing else to get in the way.


Target Selection

2. Maximal contrast – present target and contrasting word that differ by the most features (e.g., place, manner and voicing).

Again only present one contrast at a time. k/v differ on all 3 articulatory features.

As with minimal contrasts - teaching a new sound but don’t necessarily contrast it with the child’s error.

Based on the idea of making the target and the error are so different that the contrast really stands out.


Target Selection

3. Multiple contrasts – present several targets at once and contrast all of them with what the child usually does . E.g., if the child collapses 4 phonemes into 1, present

all 4 contrasts at the same time.

Introducing several new sounds at once.Based on the idea of creating the most

disruption and stimulating the child to reorganize the system.


Phonemic Therapy

Regardless of how targets are selected, the idea is to choose activities that allow the child to see how changing sounds results in changes in meaning.

Working at the word level and above.Failure to provide the appropriate sound

should result in a failure to communicate.

A note about error types

Some may disagree but it is assumed here that:

Distortion errors represent phonetic errors. Reflect some difficulty with precision of production. Haven’t completely figured out the physical aspects of

production.


Summary: Take Home Message

Errors may be perceptual, articulatory, or phonological. May be different for each error within the same child. Need to evaluate each error (or at least each error

that is not age-appropriate.

Perceptual therapy = teach to hear the contrast.

Phonetic therapy = traditional artic therapy.Phonemic therapy = focus on how changing

the sound results in a change in meaning.


treating speech-sound problems: articulatory, perceptual, or phonological intervention

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