Ertmer et al. (2002)

January 26, 2016


Single Subject Designs



  • The summary of the intervention procedure(s) can be viewed by scrolling about two-thirds of the way down on this page.



C = Clinician

CA = chronological age

CI = cochlear implant

EBP = evidence-based practice

NA = not applicable

P = Patient or Participant

pmh = Patricia Hargrove, blog developer

SLP = speech–language pathologist


SOURCE: Ertmer, D. J., & Leonard, J. S., & Pachuilo, M. L., (2002). Communication intervention for children with cochlear implants: Two case studies. Language, Speech, and Hearing Services in Schools, 33, 205- 217.




DATE: January 8, 2016


ASSIGNED OVERALL GRADE: D   (Based on the design of this investigation, the highest possible grade was D+.)


TAKE AWAY: The authors present an intervention for improving auditory perception, speech production, and oral language for children with cochlear implants. Although only a small portion of the intervention was concerned with prosody outcomes (and using prosody to improve other treatment outcomes), the approach is thorough and can be modified to meet the needs of individual children. Two case studies are presented as illustrations: a child who was moderate high functioning and a child who experience challenges.



  1. What was the focus of the research? Clinical Research



  1. What type of evidence was identified?


  • What type of single subject design was used? Case Studies Program Description with Case Illustrations


  • What was the level of support associated with the type of evidence? D+



  1. Was phase of treatment concealed? (answer Yes, No, or Unclear to each of the questions)
  • from participants? No
  • from clinicians? No
  • from data analyzers? No



  1. Were the participants (Ps) adequately described? Yes


– How many Ps were involved in the study? 2


– The CONTROLLED characteristics were

  • Status of implants: both participants (Ps) had been fitted with cochlear implants (CI)


– The DESCRIBED characteristics were

  • age hearing loss was identified:

– P1 = 3-0

– P2 = 0-5

  • age at first placement of cochlear implants (CIs)

– P1 = 7-6

– P2 = 3-0

  • age when the investigators’ intervention began

– P1 = approximately 7-6

– P2 = approximately 4 years

  • etiology of hearing loss: meningitis for both Ps
  • gender: both Ps were m
  • cognitive skills:

     – P2 = nonverbal skills were 3-1 which was higher than expected for chronological age (CA)

  • other medical issues:

   – P2 = seizures after meningitis     

  • MLU:

     – P1 =   2.86 (at CA of 7-3)

  • previous speech-language therapy:

– P1 = yes

     – P2 = yes                                  


– Were the communication problems adequately described? Yes

  • The disorder type was

   – P2 = communication severely delayed

  • List other aspects of communication that were described:

– Auditory perception of speech sounds at the beginning of intervention

  • P1 = 20% correct
  • P2 = had made little improvement in the year after implantation (before the investigation’s intervention began)

– Articulation Skills– consonants

  • P1 = 35 consonant and consonant cluster errors
  • P2 = phonetic inventory was similar to children with aids but lower than children with CI

     – Articulation Skills—vowels

  • P1 = all vowels and diphthongs were acceptable
  • P2 = phonetic inventory was similar to children with aids but lower than children with CI

– Intelligibility

  • P1 = 72% (fair)

– Prosody

  • P1 = soft, monotone

Overall communication skills

  • P2 = used some speech sounds without meaning (single vowels, consonant-vowel combinations); rarely attempted to initiate conversations, answer questions, or get attention using voice; 80% of utterances were classified as precanonical;

   – Signing skills

  • P2 = comprehended 182 signs; produced 6 signs at 4-7

– Formal Expressive and Receptive Language Testing

  • P1 = age equivalent between 4-1 and 6-3 at a CA of 7-3.
  • P2 = = age equivalent between 1 and 2 at a CA of 4-1.



  1. Was membership in treatment maintained throughout the study? Yes


  • If there was more than one participant, did at least 80% of the participants remain in the study? Yes
  • Were any data removed from the study? No



  1. Did the design include appropriate controls? No


  • Were preintervention data collected on all behaviors? Data were Provided Only for Some Outcomes


  • Did probes/intervention data include untrained stimuli? Not Provided


  • Did probes/intervention data include trained stimuli? Not Provided


  • Was the data collection continuous? No


  • Were different treatments counterbalanced or randomized? NA



  1. Were the outcome measures appropriate and meaningful? Unclear


– The outcomes/dependent variables were


  • OUTCOME #1: Ability to distinguish consonant (i.e., hat vs cat) and vowel (i.e., pet vs pat) contrasts


  • OUTCOME #2: Ability to distinguish nonspeech sounds (i.e., musical instruments, barking)


  • OUTCOME #3: Decreased rate of speech sound errors.


  • OUTCOME #4: Improved speech prosody


  • OUTCOME #5: Improved expressive and receptive language (speech and sign)


  • OUTCOME #6: Improved speech perception/listening (number of syllables, phonetically dissimilar words, important words, short phrases)


  • OUTCOME #7: “Increased quality and complexity of vocalizations” (p. 212)


  • OUTCOME #8: Increased “consonant and vowel inventory (p. 212)


  • OUTCOME #9: “Increased word production” (p. 212)


All the outcomes were subjective.


None of the outcomes were objective.


None of the outcome measures were associated with reliability data.



  1. Results:


  • Did the target behaviors improve when treated? Yes, for the most part



– The remarks for each of the Outcomes were derived from the investigators’ descriptions of the Ps’ progress.

– Some Outcomes and their results were described for both Ps and some were only described for 1 P.

– Following the P’s name, my (pmh’s) ranking of the effectiveness of the treatment for the Outcome is listed.


  • OUTCOME #1: Ability to distinguish consonant (i.e., hat vs cat) and vowel (i.e., pet vs pat) contrasts


DREW—moderate effectiveness

– Initial scores ranged from 75% correct to 90% correct

– Final scores ranged from approximately 85% to 100% correct.

– For the most part, progress was fast

– Six months after the intervention began, his score on the Minimal Pairs Test was 93%. Three months prior to implant it had been 54%. This does not appear to be a true pre-test/post test.


  • OUTCOME #2: Ability to distinguish nonspeech sounds (i.e., musical instruments, barking)


DREW—moderate effectiveness

– Achieved 90% correct for the identification of musical instruments in 2 sessions. Initially, he was 70% correct.

– This outcome was terminated early in intervention because

  • questionable impact on speech perception
  • the apparent ease of learning some of the contrasts


  • OUTCOME #3: Decreased rate of speech sound errors.


DREW—moderate effectiveness

– conversational speech was “readily intelligible” (p. 209)

– errors with consonant clusters were still noted in conversational speech


  • OUTCOME #4: Improved speech prosody


DREW (stress, loudness, intonation)—-minimal effectiveness

– loudness was usually acceptable in one-to-one conversation but was too soft in group communication

– speech was generally monotone but when he was reminded, Drew could modulate his intonation and stress.


BOBBY (pitch and voice quality) —limited effectiveness

– Age appropriate during imitative tasks


  • OUTCOME #5: Improved expressive and receptive language (speech and sign)


DREW–strong effectiveness

– Syntax and morphology improved as noted in the correct use of complete sentences and verb tenses in conversation and in written narratives

– Vocabulary continued to be a challenge

– Formal test scores improved 2 to 3 years over the course of intervention. However, Drew’s formal test scores remained 10 to 22 months below his CA.


BOBBY—limited effectiveness

– Communicated using single signs, gestures, and eye gaze

– Rarely produced 2 sign combinations, although the authors noted that these were increasing in frequency.

– The authors reported Bobby seemed to understand vocabulary items as well as “what” and “where” questions.

– Formal testing revealed:

  • receptive vocabulary of 3-7 (22 month gain in 6 months)
  • overall comprehension score = 2-4
  • overall expression score = 1-11


  • OUTCOME #6: Improved speech perception/listening (number of syllables, phonetically dissimilar words, important words, short phrases)


BOBBY—limited effectiveness

– Accurately identified phonetically dissimilar words using auditory mode only between 60-70% of the time.

– Accurately identified phonetically dissimilar words using auditory mode and speech reading between 90-100% of the time.


  • OUTCOME #7: “Increased quality and complexity of vocalizations (p. 212)



– Improved imitation but limited progress with spontaneous vocalizations


  • OUTCOME #8: Increased “consonant and vowel inventory (p. 212)


BOBBY—limited effectiveness

– Improved imitation when model was accompanied by visual (spectrographic) feedback but limited progress with spontaneous vocalizations

– 90% of his spontaneous vocalizations were still considered to be precanonical


  • OUTCOME #9: “Increased word production” (p. 212)


BOBBY—Ineffective effectiveness

– When imitating 1 to 3 syllable words, the number of syllables usually was accurate.

– When imitating 4 syllable words, Bobby produced 3 syllables

– Produced selected words on request but little spontaneous speech.



  1. Description of baseline:


  • Were baseline data provided? No


  • Was the percentage of nonoverlapping data (PND) provided? No


Only for the following Outcomes ___________

— Proceed to item 10, if the answer to item 9c is NO.



  1. What is the clinical significanceNA, data pertaining to clinical significance were not provided.



  1. 11. Was information about treatment fidelity adequate?   No



  1. Were maintenance data reported? No



  1. Were generalization data reported? No



  1. Brief description of the design:
  • The investigators /authors describe an intervention protocol for children with CI.
  • They provide evidence describing the effectiveness of the program but not all outcomes were associated with clearly presented pre and post data.








PURPOSE: To describe an intervention program for children with CI


POPULATION: Hearing Loss, Cochlear Implant; Children


MODALITY TARGETED: expression; comprehension


ELEMENTS/FUNCTIONS OF PROSODY TARGETED: pitch, intonation, stress, loudness




OTHER ASPECTS OF LANGUAGE/COMMUNICATION TARGETED: auditory perception, speech sound production, overall expressive and receptive language, vocalizations, word production, syntax/morphology




DOSAGE: 1 hour sessions, 2 times a week, 20 months (Drew); 90 minute sessions, 1 time a week, 1 year (Bobby)






  • The authors described an intervention program for child with CI based on

– treatment procedures that have been reported to be effective

– a knowledge of speech acoustics

– reports from experts in treating children with cochlear implants


  • The authors described the application of the program to two children:

– a moderately high functioning child (Drew)

– a child who continued to have challenges following the implant (Bobby)


  • The major content areas of the intervention were

– Auditory Training (Drew, Bobby)

– Language Stimulation (Bobby)

– Speech Production (Drew, Bobby)

– Oral Language (Drew)


  • For the most part, in each session the Cs targeted all the major content areas, although the amount of time devoted to tasks could vary.





  • Auditory Training took 2 forms: analytic and synthetic.


  • Analytic Auditory Training


  • The Appendix contains a thorough description of treatment procedures and goals associated with analytic Auditory Training.


  • Minimal pairs were used as stimuli. After introducing a pair of words, the clinician (C) directed the P to select the word she said without speech reading cues. If the P failed, speech reading cues were added but faded when possible.


  • The authors recommended using

– a diverse group of speakers (including the P)

– words that are common and important in P’s environment

– positive feedback to keep the activity fun and encouraging

– minimal pairs in the medial and final position as well as the initial position


  • For Bobby, the C also used a special intonation pattern, choral speech, reinforcement, and sabotage.


  • In addition, the authors recommended using this task in a variety of activities—narratives, games, play, conversation, etc.


  • The hierarchy of tasks was

– nonspeech sounds

– suprasegmental (prosodic) elements

– phonemically different words

– consonant and vowel feature


  • Synthetic Auditory Training


  • Synthetic Auditory Training focused on perception in connected speech.


  • Treatment activities:

– Name recognition and recognition of activities of daily living (Bobby)

– Reading predictable books interactively with C and with P’s mother (Bobby)

– Viewing picture books and identifying items in the book (Drew)

– Short conversations about selected topics in which P was encouraged to guess if he was not sure what had been said. False assertions and communication repairs were also used (Drew.)

– Story telling in which P was directed to imitate selected sentences and to ask for repetitions and clarifications (Drew)

– Riddles and jokes (Drew)




  • Following the auditory training component of a session, P practiced producing selected consonants in isolation or in cognate pairs. P progressed to producing the targeted sounds in single words (Drew.)


  • Because production of the sounds in connected speech was a challenge, P practiced producing the targeted sound in words at a rate of 3 words per second (Drew.)


  • C targeted prosody objectives by having P sing songs as well as recite nursery rhymes and poems using appropriate stress and intonation (Drew.)


  • Another target involved increasing expression during conversation (Drew.)


  • The following techniques were use:

– “self-evaluation,

– false assertions,

– negative practice….,

– and minimal pair contrasts” (p. 209, Drew.)


  • Certain activities were used to motive the P and facilitate generalization:

– jokes and riddles with the target sounds

– inclusion of sports related words on word lists

– magic tricks (Drew)


  • To increase loudness, P practiced while C was a considerable distance from him (Drew.)


  • The C modeled targeted vocalizations for P and encouraging him to imitate (Bobby.)


  • Spontaneous vocalizations, which were rare, were encouraged (Bobby.)


  • Viewed spectrographic displays as feedback and reinforcement (Bobby.)




  • Procedures included both signs and speech.


  • Targeted words in short sentences were emphasized and required many repetitions

– C used emphasis (stress) and melody (intonation) to highlight targeted words


  • Targets included

– vocabulary (targeted words were grouped into categories—food, furniture, animals, etc.)

– verbs were taught in the context of direction following


  • C held pictures and objects by her mouth to facilitated attending to speech reading cues.


  • The game “Hide and Seek” was used to motive P.




  • P used picture dictionaries and theme related picture books and developed his own personal dictionary to assist him in pronouncing and listening to words.


  • School vocabulary was pretaught.


  • P’s parents and teachers also worked with him to explain new words.


  • C introduced syntactic and morphological rules and then they were practiced in less structured activities such as games, books, and comics.


  • As P improved, C targeted inferences and narrative (oral and written.)