Treating Speech-Sound Problems: Articulatory, Perceptual, or Phonological Intervention

1. Treating Speech-Sound Problems:Articulatory, Perceptual, or Phonological Intervention Peter Flipsen Jr., Ph.D., CCC-SLP Idaho State University flippete@isu.edu http://www.isu.edu/~flippete/default.html IMASH 2008 - Salt Lake City, UT

2. 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. IMASH 2008 - Salt Lake City, UT

3. 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’. IMASH 2008 - Salt Lake City, UT

4. 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. IMASH 2008 - Salt Lake City, UT

5. 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. IMASH 2008 - Salt Lake City, UT

6. 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! IMASH 2008 - Salt Lake City, UT

7. 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. IMASH 2008 - Salt Lake City, UT

8. 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. IMASH 2008 - Salt Lake City, UT

9. 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. IMASH 2008 - Salt Lake City, UT

10. 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. IMASH 2008 - Salt Lake City, UT

11. 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). IMASH 2008 - Salt Lake City, UT

12. Identifying Perceptual Problems • 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. IMASH 2008 - Salt Lake City, UT

13. Identifying Perceptual Problems • 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. IMASH 2008 - Salt Lake City, UT

14. 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. IMASH 2008 - Salt Lake City, UT

15. 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. IMASH 2008 - Salt Lake City, UT

16. Articulatory or Phonological? • 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. IMASH 2008 - Salt Lake City, UT

17. Articulatory or Phonological? • 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. IMASH 2008 - Salt Lake City, UT

18. 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. IMASH 2008 - Salt Lake City, UT

19. 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. IMASH 2008 - Salt Lake City, UT

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21. 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 IMASH 2008 - Salt Lake City, UT

22. 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. IMASH 2008 - Salt Lake City, UT

23. 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. IMASH 2008 - Salt Lake City, UT

24. 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. IMASH 2008 - Salt Lake City, UT

25. 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). IMASH 2008 - Salt Lake City, UT

26. Phonemic Therapy: Principles • 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. IMASH 2008 - Salt Lake City, UT

27. 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”. IMASH 2008 - Salt Lake City, UT

28. Phonemic Therapy: Principles • 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"). IMASH 2008 - Salt Lake City, UT

29. Phonemic Therapy: Principles • 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). IMASH 2008 - Salt Lake City, UT

30. 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). IMASH 2008 - Salt Lake City, UT

31. 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” IMASH 2008 - Salt Lake City, UT

32. 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. IMASH 2008 - Salt Lake City, UT

33. 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. IMASH 2008 - Salt Lake City, UT

34. 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. IMASH 2008 - Salt Lake City, UT

35. 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. IMASH 2008 - Salt Lake City, UT

36. 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. IMASH 2008 - Salt Lake City, UT

37. 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. IMASH 2008 - Salt Lake City, UT

38. 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. IMASH 2008 - Salt Lake City, UT

39. 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. IMASH 2008 - Salt Lake City, UT