communication sciences & disorders · broniewicz, a. 5 do speech impairments alone negatively...

School of

Communication Sciences & Disorders

Procee!ngs of

"e Second Annual CSD Research Day

February 10, 2$6

the Second Annual CSD Research DayFriday, February 10th, 2006

Poster Session #1: 1:00pm to 2:00pm

PosterNo.1 The use of speech supplementation to improve speech intelligibility for patients with dysarthria

Ambrose, K.2 Therapeutic use of Antioxidants in the Protection from Noise Induced Hearing Loss

Beach, C.H.3 Psychophysical evaluation of pleasantness and acceptability for electrolaryngeal speech

Beaudin, P.G., Eadie, T.L., & Doyle, P.C.4 Do Cochlear Implants Provide Significant Reduction in Tinnitus Levels in Adult Patients?

Broniewicz, A.5 Do speech impairments alone negatively impact literacy development?

Charette, C.6 A case study evaluation of hearing aid frequency compression

Glista, D., Scollie, S., & Parsa, V.7 The Effectiveness of PECS on the Development of Communication in Children with Autism

Spectrum DisordersGreene, S.E.

8 The Efficacy of Peer-Mediated Intervention for Increasing Social Functioning of Children WithAutismGrigg, D.M.

9 The effectiveness of surface electromyography in swallowing management of patients withoropharyngeal dysphagiaHarkot, K.E.

10 The Reliability and Validity of Cervical Auscultation as a Dysphagia Assessment Tool.Harp, L.

11 The Effects of Computer-Based Interventions on Improving Phonological Awareness in Childrenwith or at Risk for Reading ProblemsKalka, M.M.

12 Effects of Prolonged Endotracheal Intubation on Swallowing FunctionKilian, S.L.

13 How can occlusion and ampclusion be alleviated?Kim, M.

14 Does Occupational Noise Exposure during Pregnancy have an Adverse Effect on the AuditorySystem of the Developing Fetus?King, L.

15 The efficacy of pharyngeal flap and sphincter pharyngoplasty surgery on resonance in the treatmentof velopharyngeal insufficiencyMcAskill, C.A.

16 Speech perception outcomes in children with cochlear implants compared to conventional hearingaidsMiceli, S.

17 Costs to workers’ compensation systems for approved noise-induced hearing loss claimsMignelli, L.M.

the Second Annual CSD Research DayFriday, February 10th, 2006

Poster Session #2: 2:00pm to 3:00pm

PosterNo.1 Impact of Early Cochlear Implantation on Oral Language Development

Molenhuis, J.2 The effects of signal to noise ratio on sentence recognition in children with and without hearing loss

Ng, S., & Scollie, S.3 The effectiveness of Lee Silverman Voice Treatment in patients with hypokinetic dysarthria

Nicholls, S.N.4 Efficacy of classroom intervention methods for children diagnosed with a permanent unilateral

hearing lossPowell, M.

5 The effectiveness of pulse oximetry in detecting aspirationRody, C.

6 The Impact of Otitis Media on the Development of Language in the Preschool ChildRoloson, A.

7 Does Cochlear Implantation Improve Speech Perception in the Geriatric Population?Sadra, N.

8 The effectiveness of Functional Communication Training (FCT) in reducing behavior problems inautistic or developmentally disabled personsSaleh, S.

9 Drawing therapy and its effect as a means of communication in patients with severe non-fluentaphasiaSamaan, S.

10 The effectiveness of tinnitus retraining therapy for treating hyperacusisShin, G.

11 What Evidence is there to Support the Bilingual-Bicultural Model of Literacy Education for theDeaf?Soltys, A.J.

12 Does Speech Perception Training Improve Sound Production for Children with Articulation orPhonological Disorders?Stephenson, R.

13 Is the modified barium swallow a reliable method of assessing swallowing function?Stewart, R.L.

14 What evidence is there that auditory verbal therapy is effective?van Eendenburg, K.

15 Effectiveness of bilateral and unilateral botox injections for the treatment of adductor spasmodicdysphoniaVarghese, M.

16 Effectiveness of therapy approaches for Developmental Apraxia of SpeechVreugdenhil, T.

17 The Effect of a Chin Tuck Posture on Swallow FunctionWeber, K.A.

Copyright © 2006 by Ambrose, K.

Critical review:The use of speech supplementation to improve speech intelligibility for patients with dysarthria

Ambrose, K.M.Cl.Sc. (SLP) Candidate

School of Communication Sciences and Disorders, U.W.O.

This critical review examines whether implementing speech supplementation (alphabetcues, topic cues and combined cues) will improve the speech intelligibility of subjectswith dysarthria. Study designs include: within subjects design (5). Overall, researchsupports that combined cues, as well as alphabet cues, can improve the speechintelligibility of dysarthric subjects.

Introduction

Dysarthria is characterized by articulation difficultiesfrom damage to the nervous system (Borden, Harris &Raphael, 2003) and is a common speech characteristicamong patients with traumatic brain injury (TBI) andcerebral palsy (CP) (Beukelman, Fager, Ullman,Hanson & Logemann, 2002; Hustad, Auker, Natale &Carlson 2003). Intelligibility is generally a goal oftreatment for patients with dysarthria, as poorintelligibility is typical of their speech in everydaycommunication. In the field of speech languagepathology, intelligibility is seen as something that canbe considered a part of a person and can contribute tothe overall importance of their communication messagefrom the listener’s perspective (Hustad, Jones & Dailey,2003).

There are a number of different speech supplementationstrategies, or AAC strategies, that have been suggestedto improve the intelligibility of dsyarthric subjects.These include topic, alphabet and combined cues.When using topic cues, listeners are given cuesregarding the general topic the speaker will becommunicating about. These cues can be given inwritten form or by use of a communication board andpicture symbols (Hustad, Jones et al., 2003). Whenalphabet cues are used, speakers give listeners the firstletter of each word they are going to be speaking byusing the alphabet board. Giving the listener the firstletter of the word can limit the possible words thespeaker could be saying (Hustad, Jones et al., 2003).Finally, combined cues are when speakers use bothalphabet and topic cues. (Hustad, Jones et al., 2003).

Objectives

The primary objective of this paper is to criticallyevaluate existing literature regarding the influence ofspeech supplementation on improving speechintelligibility of patients with dysarthria. The secondaryobjective is to propose evidence-based practice

recommendations for future research andimplication of speech supplementation for patientswith dysarthria.

Methods

Search StrategyComputerized databases, including CINAHL,MEDLINE and PubMed, were searched using thefollowing search strategy:

(Dysarthria) and (speech supplementation)OR (AAC) OR (linguistic cues)

The search was limited to articles written inEnglish between 1980 and 2005.

Selection CriteriaResearch studies selected for inclusion in thiscritical review paper were required to investigatethe impact of speech supplementation (alphabet,topic and combined cues) on speech intelligibilityof patients with dysarthria. No limits were set onthe demographics of the research participants.

Data CollectionResults of the literature search yielded thefollowing types of articles congruent with thechosen selection criteria: within subjects design(5).

Results

Impact of speech supplementation onintelligibilityBeukelman et al. (2002) looked at differences inintelligibility and speaking rate scores for 8traumatic brain injury (TBI) patients withdysarthria, when speech supplementation strategieswere implemented and compared to the use of nocues. Ten listeners determined intelligibility foreach strategy, while 1 listener used a visual displayof the acoustic waveform to determine the speaking

THE USE OF SPEECH SUPPLEMENTATION TO IMPROVE SPEECH INTELLIGIBILITY FOR PATIENTS WITH DYSARTHRIA

rate. After the participants were videotaped using thedifferent strategies for a total of 16 sets of sentences (adifferent set of sentences for each strategy and no cues)video clips were digitally edited. Analysis wascompleted by the use of a paired t-test and results forindividual participants as well as group data showedthat implementing alphabet cues was associated withthe most improvement on speech intelligibility.

Hustad, Auker et al. (2003) used a repeated measuresdesign to look at whether intelligibility scores changedwhen three cerebral palsy (CP) participants, withprofound dysarthria, used different speechsupplementation strategies. Participants werevideotaped while reading four passages using thedifferent strategies that were taught and learned inapproximately fifteen minutes. Twenty-four listenerswatched the videotapes of each participant reading the 4passages while using only one of the strategies.Analysis was completed by the use of a split-plotanalysis of variance (ANOVA) and a non-parametricanalysis for repeated measures, similar to an ANOVA,which are both appropriate for the research design.Results looked at both group and individual data,overall results indicated that using combined cueshelped increase intelligibility scores across all speakersand listeners felt that for the majority of speakers,combined cues were the most effective strategy to usewhen communicating.

Hustad, Jones et al. (2003) used a 4 x 5 split plot designto determine whether speech supplementation strategieswould affect the intelligibility and speaking rate of 5participants with severe dysarthria (4 patients with CPand 1 patient with TBI) when compared to the use of nocues. A total of 120 listeners (24 listeners for eachparticipant) watched videotapes of the participantsusing one of the strategies while reading one of fourpassages. One experimenter using a spectrographicdisplay determined the speaking rates of theparticipants. To verify this information a second personused this technology to determine the speaking rates oftwo sentences for each participant. Analysis wascompleted using an appropriate a-priori approach toanalysis of variance (ANOVA) for this research design.Results showed that both combined and alphabet cueshelped participants make improvements in theirintelligibility and the use of alphabet cues decreased thespeech rate of the participant the most.

Hustad and Beukelman (2001) used a 2 x 4 repeatedmeasures design to look at whether intelligibility scoreschanged when participants, with CP and severedysarthria, used different speech supplementationstrategies as well as the use of no cues when readingrelated and unrelated sentences. Participants were

videotaped producing all 160 sentences (10sentences per passage) and data was taken andedited to make 24 different videotapes for listenersto watch. A total of 3 listeners watched eachvideotape, which consisted of 80 sentences, 40related (part of a narrative) and 40 unrelated. Theauthors did not explicitly mention how many timesan individual participant was viewed on eachvideotape, but that each sentence, of the 160possible sentences, were seen approximately 12times throughout the strategies and videos.Listeners watched the videos that displayed thealphabet, topic or combined cues and the audioinformation of the four participants speaking twotimes. Analysis of the information was conductedthrough an a priori approach to ANOVA, anappropriate type of analysis for this study, andresults concluded that the use of combined cuesincreased intelligibility scores across thevideotapes and that for alphabet cues,improvements in intelligibility were seen the mostin the related sentences.

In a follow up study, Hustad and Beukelman(2002), looked at whether using speechsupplementation strategies would improvelistener’s comprehension of communicativemessage in four subjects with CP and severedysarthria. The researchers went to great efforts tomake sure that topic cues and comprehensivequestions were appropriate for the given sentences;specifically comprehensive questions were testedon a set of judges to make sure that the questionswere not guessable and could be used to determinewhether the listener comprehended theparticipant’s message. Like the previous study,participants were videotaped reading all of the 160sentences and this information was then edited tomake 24 different videos. Listeners watched videosthat showed all four participants, each using adifferent strategy. In the videos, all of the sentenceswere shown between the participants, some of thesentences were used as related sentences (as part ofone of the 16 narratives) and others were used ontheir own as unrelated sentences. This occurredamong the sentences that were used forintelligibility scores and the sentences used forcomprehension. Data was analyzed by the use of aplanned approach to ANOVA and results showedthat combined cues improved comprehension themost and comprehension was higher withsentences that were related (part of a narrative)when compared with the unrelated sentences for allstrategies. Results also indicated that there was asignificant relationship between intelligibility andcomprehension for topic cues with unrelated


sentences, and alphabet cues with related sentences.

Discussion

Appraisal of the resultsIt is important when looking at the results of thisresearch evidence, to address issues with regard tosubject selection, sample size and methodology in theliterature. It is important to consider these issues whenlooking at the literature and understand that these issuesmay impact the strength of the evidence.

Subject Selection and sample sizeThe most obvious issue with regard to subject selectionwas that researchers did not mention whether subjectswere randomly selected to participate in the researchstudy (Beukelman et al., 2002; Hustad, Auker et al.,2003; Hustad & Beukelman, 2001; Hustad et al., 2002;Hustad, Jones et al., 2003).. Random selection ofparticipants is important for representing andgeneralizing research findings to the dysarthriapopulation as a whole.

The sample sizes in these studies were small (rangingfrom 3 to 8) which could also limit the generalizabilityof the findings.

MethodologyWhen interpreting the results of the studies, it isimportant to consider limitations of the methodologies,in particular prominent information that was notincluded in the research descriptions.

Information regarding the participant’s communicationdifficulties was not included in the methodology(Beukelman et al., 2002; Hustad, Auker et al., 2003;Hustad & Beukelman, 2001; Hustad et al., 2002;Hustad, Jones et al., 2003). It would be important toknow how long the participants had experienced theircommunication problems.

Researchers failed to state how much time they allowedfor the participants to learn the new speechsupplementation strategies before they were videotapedfor the study (Hustad & Beukelman, 2001; Hustad &Beukelman, 2002). Beukelman et al. (2002) showedparticipants the speech supplementation strategies andexperimenters decided when the participants had gainedcompetency using the strategy or an hour of practicehad passed. It is hard to determine whether theparticipants in these studies were using the strategieswith 100% precision, which could influenceintelligibility scores.Researchers failed to state how topic cues weredetermined for the speech supplementation strategiesduring the study (Beukelman et al., 2002; Hustad, Jones

et al., 2003; Hustad, Auker et al., 2003). It isimportant to understand how topic cues weredetermined as it is possible they could affectintelligibility scores as well. Topic cues could givetoo much information and would make it easy forlisteners to decide what the participants had said ortopics may not represent what the sentence isabout.

During the assembly of the videotapes that were tobe viewed by the listeners, researchers instructedparticipants to repeat sentences if they mademistakes when implementing the strategies(Hustad, Auker et al., 2003; Hustad, Jones et al.,2003). Editing was also done on the videotapesbefore the listeners watched them. The volume wasincreased, alphabet and topic cues were enhancedon the videos so they could be seen by the listeners,and the cues lasted from between 1 and 3 secondsor as long as the participants were speaking(Beukelman et al., 2002; Hustad, Auker et al.,2003; Hustad & Beukelman, 2001; Hustad et al.,2002; Hustad, Jones et al., 2003). Listeners werealso instructed by the researchers to listen to thevideotapes two times and during the secondviewing they were asked to write down what theythought was said (Hustad , Auker et al., 2003;Hustad & Beukelman, 2001; Hustad & Beukelman,2002; Hustad, Jones et al., 2003). These variablesmay not be as easily altered in a naturalcommunication interaction. In a real face-to-faceinteraction, mistakes will be made when using thestrategies and speakers will have to make revisions.In face-to-face interactions, listeners can also askfor repetition when a message is not understood.However, in these studies, allowing the listeners towatch the videotapes twice potentially helped toimprove their familiarity of the sentence.

Recommendations

After reviewing the research evidence, it isimportant to acknowledge for clinical applicationthat all of the studies were experimental.

For future research it is recommended thatresearchers be sure to include relevant andimportant information for the readers to fullyunderstand their methodology and conclusions

It will be important for future research to beimplemented into a natural communication setting,where speakers and listeners can interact face-to-face. During face-to-face interactions, intelligibilityscores can be determined when speakers are usingtheir strategies in environments that may subject


them to background noise; participants can decide whatthey want to say instead of reading predeterminedsentences; listeners can ask participants to repeat whatthey have said when they do not understand;participants with limited motor abilities, may find itdifficult to implement the strategies and listeners maynot be able to see the cues as easily when participantsare pointing to them which could affect intelligibilityrates for the different speech supplementationstrategies.

It may also be important for researchers to incorporatethe thoughts and feelings of the participants with regardto their competency of strategy use as well as moreresearch about how listeners feel when speakers areusing these strategies.

Conclusions

The present research findings suggest thatimplementing the use of combined or alphabet cues canhelp increase the intelligibility of individuals withsevere dysarthria. This information is important forresearchers to consider when suggesting the use ofspeech supplementation strategies to their patients.Even though the research is very much experimental innature, there were significant improvements inintelligibility. Although further research involving theuse of cues in a natural setting is required, the findingsfrom these studies support the use of speechsupplementation for intelligibility deficits in subjectswith severe dysarthria.

References

Beukelman, D.R., Fager, S., Ullman, C., Hanson,supplementation and clear speech on theintelligibility and speaking rate of people withtraumatic brain injury. Journal of Medical Speech-Language Pathology, 10, 237-242.

Borden, G.J., Harris, K.S. & Raphael, L.J. (2003).Speech science primer: Physiology, Acoustics, andperceptions of speech. Philadelphia, PA: LippincottWilliams & Wilkins.

Hustad, K.C., Auker, J., Natale, N. & Carlson, R.(2003). Improving intelligibility of speakers withprofound dysarthria and cerebral palsy. AAC:Augmentative and Alternative Communication, 19,187-198.

Hustad, K.C. & Beukelman, D.R. (2001). Effects oflinguistic cues and stimulus cohension onintelligibility of severely dysarthric speech.Journal of Speech, Language and HearingResearch, 44, 497-519.

Hustad, K.C. & Beukelman, D.R. (2002). Listenercomprehension of severely dysarthria speech:

Effects of linguistics cues and stimuluscohesion. Journal of Speech, Language andHearing Research, 45, 545-559.

Hustad, K.C., Jones, T. & Dailey, S. (2003).Implementing speech supplementationstrategies: Effects of intelligibility and speechrate of individuals with chronic severedysarthria. Journal of Speech, Language andHearing Research, 46, 461-474.

Copyright © 2006 by Beach, C.H..

Critical Review:Therapeutic use of Antioxidants in the Protection from Noise Induced Hearing Loss

Beach, C.H.M.Cl.Sc. (Aud) Candidate


This critical review considers the potential efficacy of using specific antioxidantcompounds: N-L-acetylcysteine (NAC), acetyl-L-caritine (ALCAR) and D-methionine(D-met) to protect against noise induced hearing loss. Each of the studies employed anexperimental design using animal subjects with analysis of variance and post-hoc testing.Overall, the examined research supports the feasibility of pharmacological intervention inproviding some protection of cochlear integrity in toxic noise environments; however, todate, the effects of these compounds have not been studied in a human population.

Introduction

Given the large number of patients with NoiseInduced Hearing loss (NIHL), there has been anincreased interest in searching for agents that couldprotect or repair cochlear hair cells from excessivenoise exposure. Clearly the most direct way toprevent harmful levels of noise exposure is to useappropriate hearing protection or to avoid exposurealtogether; however, there are certain instances, forexample, in military settings, when exposure toharmful noise levels is unavoidable.

There has been some evidence that some naturalprotection from NIHL may occur due to lifestyle. Forexample, a high-fat diet, smoking and heavy alcoholconsumption have each been correlated with higherincidences of hearing loss, while moderate alcoholconsumption and exposure to music that is enjoyable,as opposed to music that is not enjoyable, decreasesthe risk of NIHL (Campbell, 2004). It would seemlogical that enhancing the body’s natural defencemechanisms may help to prevent damage fromharmful forces, including noise.

Antioxidants are substances produced naturally in thebody that help to protect the tissues from damagecaused by free radicals. Some antioxidants areformed naturally in the body, while others must besupplied in the diet. Free oxygen radicals (FOR) areatoms with an odd (unpaired) number of electronsthat are formed when oxygen interacts with certainmolecules. This interaction can cause damage tocells, which may impair the immune system and leadto infections and various degenerative diseases.Antioxidants defuse free radicals by binding to theirfree electrons.

Also known as reactive oxygen species (ROS), thesefree radicals have been found to form in the inner ear

after exposure to high-intensity noise, and arebelieved to play an important role in the haircelldamage that leads to NIHL (Yamashita et al, 2004).

Stimulation of the haircells causes increasedgeneration of free radicals. In response, the cochleaproduces antioxidant enzymes, antioxidant moleculesor glutathione (GSH), as a defensive measure. Whenthese antioxidant defenses are overwhelmed, the haircell is susceptible to injury to its DNA, mitochondria,and membranes. When hair cells are damaged in thisway, they are prone to a genetically programmed celldeath sequence (known as apoptosis), in which theongoing loss of hair cells can continue for days toweeks after an acute exposure to loud noise (Kopke,2003).

Evidence for the protective capabilities ofantioxidants comes from two lines of research. Firstare studies of “toughening” where a series of non-traumatic noise exposure episodes function to makethe ear more resilient to the effects of otherwise toxicnoise levels. The second line of evidence comes fromstudies of direct pharmacological interventions(Henderson et al). Recent studies have assessed theprotective efficacy of antioxidants (Karlida et al,2002, Gok et al, 2004, Sergi, et al, 2004, Kopke et al,2005) with overwhelmingly positive results.

Three antioxidants, which are already approved bythe United States Food and Drug Administration(FDA) for alternate uses, have recently been cited ashaving promising otoprotective ability (Campbell,2004) and can be administered orally without adverseside effects. Current literature on the efficacy ofusing specific antioxidant compounds: N-L-acetylcysteine (NAC), acetyl-L-caritine (ALCAR)and D-methionine (D-met) to protect against noiseinduced hearing loss (Duan et al., 2004; Kopke et al.,2000; Kopke et al., 2002; Kopke et al., 2005; Ohinata

THERAPEUTIC USE OF ANTIOXIDANTS IN THE PROTECTION FROM NOISE INDUCED HEARING LOSS

et al., 2003) will be evaluated to assist in determiningif a pharmacological intervention might beconsidered in a comprehensive approach tomaintaining cochlear integrity in toxic noiseenvironments.

Objectives

The objective of this paper is to critically evaluateexisting literature regarding the efficacy of usingspecific antioxidant compounds: N-L-acetylcysteine(NAC), acetyl-L-caritine (ALCAR) and D-methionine (D-met) to protect against noise inducedhearing loss.

Methods

Search StrategyComputerized databases, including PubMed, ComDisDome and MEDLINE-Ovid, were searched using thefollowing search strategy:

((Noise induced hearing loss) OR (NIHL))AND ((antioxidant) OR (NAC) OR(ALCAR) OR (pharmacological)).

Selection CriteriaStudies selected for inclusion in this critical reviewpaper were required to investigate the impact of anyone or any combination of the specified antioxidants.Selection was limited to studies of antioxidant effecton hearing loss due noise toxicity.

Data CollectionResults of the literature search yielded five studiesthat met the aforementioned selection criteria. Eachof the included studies implemented an experimentaldesign with animal subjects.

Results

In all but one of the studies, experimenters wereexperienced and blinded as to the conditions of theanimals for the entire study. They used a selection ofhomogeneous animals controlled for weight, pre-treatment thresholds, and sex. This is particularlyimportant as sex differences have been associatedwith differing ability to detoxify ROS and varyingactivity of glutathione S-transferase in the cochlea(McFadden et al, 1999).

Internal validity, which is important in establishing acausal relationship, was ensured in each of the studiesby using the auditory brainstem response (ABR) forscoring both pre- and post-treatment thresholds. Thisuse of repeated measures has the advantage of beingquite powerful because subjects are used for their

own controls, thereby reducing possible error. AsABR is a non-behavioural test, repeated exposureeffects were non-applicable. The incidence ofthreshold shift, both temporary and permanent, canbe determined quickly, so any potential effects ofmaturation or attrition were avoided.

The protective effects of the antioxidants: NAC andALCAR against NIHL were investigated by Kopke etal. in 2005. Kopke and his colleagues havepreviously undertaken similar studies. In 2000 theyinvestigated the efficacy of utilizing a combination ofantioxidant compounds (salicylate and NAC) toeither prevent or attenuate the level of NIHL. In asubsequent study (2002) they examined the effect ofthe antioxidants ALCAR and D-Met, as well as an N-methyl-D-aspartate (NMDA) antagonist,Carbamathione, on limiting NIHL.

A 2003 study by Ohinata et al. assessed the effect ofseveral pharmacological agents, including NAC, ontheir ability to protect against noise trauma in themale guinea pig in order to delineate mechanisms ofNIHL. A total of five different pharmacologicalagents were examined, two combined, and two salinecontrol groups, for a total of eight treatment groups.A non-exposed control group was added in order tomeasure lipid peroxidation (8-isoprostane formation).

The study by Duan et al (2004) investigated the effectof NAC in the protection of the cochlea against noisetrauma and tested the hypothesis that the degree ofprotection is dose and time-dependent.

Each of the examined studies employed appropriatestatistical treatment of the data in the form of one-,two-, or three-way analyses of variance (ANOVA)and appropriate post-hoc testing with a P value of <0.05.

Impact of antioxidants on threshold shiftIn each of the studies, baseline ABRs were measuredprior to noise exposure and there was no significantpre-noise threshold difference between the groups.The ABR is a reliable, valid, and sufficientlysensitive measurement tool commonly used fordetermining threshold, and the use of a repeatedmeasure protocol would effectively determine thatthe exposure to noise preceded any changes inthreshold. Noise exposure conditions included bothcontinuous and impulse stimuli ranging from 105dBSPL to 160dB SPL at a number of differentfrequencies.

Post-exposure ABRs were conducted at several pre-determined intervals from 15 minutes to three weeks,


and hearing loss was observed after noise exposure inall groups. Initial post-exposure testing revealedthresholds ranging from about 30dB at 1kHz to 87dBin the higher frequencies in both the control groupsand those treated with ALCAR or D-Met (Kopke etal., 2002). The groups treated with NAC showedsignificantly less threshold shift immediatelyfollowing noise exposure (Duan et al., 2004; Kopkeet al., 2000; Kopke et al., 2005).

In subsequent ABR tests, all three antioxidanttreatments were seen to result in a recovery ofthreshold shift. As compared to the controls, animalstreated with D-Met showed an overall treatmenteffect (P


hearing protection are currently the most valuablesafeguard against cochlear noise damage.

References

Campbell, K.C.M., (2004) Oxidants Vs. antioxidants:The war within – and our cells are at stake. TheHearing Journal vol: 57 issue 5, 10-17

Campbell, K.C.M. (2004) Otoprotective agentssought for noise-induced hearing loss. TheASHA Leader

Duan, M., Qiu, J., Laurell, G., Olofsson, A., Counter,S.A., Borg, E., (2004) Dose and time-dependentprotection of the antioxidant N-L-acetylcysteineagainst impulse noise. Hearing Research 192:1-9

Kopke, R.D., Weisskoph, P.A., Boone, J.L, Jackson,R.L., Wester, D.C., Hoffer, M.E., Lambert, D.C.,Charon, C.C., Ding, D.-L., McBride, D., (2000)Reduction of noise-induced hearing loss using L-NAC and salicylate in the chinchilla. HearingResearch 149: 138-146

Kopke R.D., Coleman, J.K, Liu, J., Campbell, K.C.,Riffenburgh, R.H. (2002) Candidate’s thesis:enhancing intrinsic cochlear stress defenses toreduce noise-induced hearing loss.Laryngoscope, 112:1515-32

Kopke, R.D., Danielson, R. W., (2003) Antioxidants– Good for your health – Good for your hearing.The Newsletter of the Council for Accreditationin Occupational Hearing Conservation Volume15, Issue 1

Kopke, R., Bielefeld, E., Liu, J., Zheng, J., Jackson,R., Henderson, D., Coleman, J.K.M., (2005)Prevention of impulse noise-induced hearing losswith antioxidants. Acta Oto-laryngologica, 125:235-243

Lynch, E. D., & Kil, J. (2005) Compounds for theprevention and treatment of noise-inducedhearing loss. Drug Discovery Today, Volume 10,Number 19

McFadden, S.L., Henselman, L.W., Zheng, X-Y,(1999) Sex Differences in Auditory Sensitivityof Chinchillas Before and After Exposure toImpulse Noise. Ear and Hearing April 20 (2):164-74

Ohinata, Y., Miller, J. M., Altschuler, R. A., andSchacht, J. (2000). Intense noise inducesformation of vasoactive lipid peroxidationproducts in the cochlea. Brain Research 878,163-73.

Ohlemiller, K.K., (2003) Oxidative Cochlear Injuryand the Limitations of Antioxidant Therapy.Seminars in Hearing, volume 24, number 2

Copyright © 2006, Beaudin, P.G., Eadie, T.L., & Doyle, P.C.

Psychophysical Evaluation of Pleasantness and Acceptability for Electrolaryngeal Speech

Beaudin, P.G., Eadie, T.L., & Doyle, P.C.Doctoral Program in Rehabilitation Sciences

This investigation gathered information on the psychophysical, auditory-perceptual (AP)characteristics of electrolaryngeal (EL) speech. Electrolaryngeal speech is widely used asa postlaryngectomy method of speech rehabilitation. Sentence stimuli produced bylaryngectomized speakers using the Servox EL were assessed by 20 naïve listeners forthe perceptual features of pleasantness (PL) and acceptability (AC). Methodologicalconcerns influencing psychophysical measurement of each psychophysical dimensionand the related empirical and clinical implications are discussed.

Copyright © 2006, Broniewicz, A.

Critical Review:Do Cochlear Implants Provide Significant Reduction in Tinnitus Levels in Adult Patients?

Broniewicz, A.M.Cl.Sc. (Aud) Candidate


This critical review examines the effects of cochlear implants on the reduction of tinnitusin the adult population. Study designs include prospective and retrospective cohortstudies and cross-sectional designs. Overall, research supports the hypothesis thatcochlear implantation does in fact have some effect on the reduction of tinnitus; howeverdue to the un-standardized nature of the outcome measures used, results were difficult tocompare among the various studies.

Introduction

Tinnitus is the sensation of ringing in the ear(s) thatoccurs without any external presence of sound. It canbe a debilitating phenomenon for which cause andtreatment are still being researched. Reports showthat roughly 5-8% of all patients who visitotolaryngology clinics suffer from tinnitus, and that80% of patients with ear disease have tinnitus (Ito,1994a). Although a variety of procedures can helptinnitus sufferers adapt to their tinnitus sensation, atpresent there are no treatments that reliably eliminatetinnitus completely (Eggermont, 2004). One of thecurrent treatment modalities for tinnitus involves theuse of acoustic stimuli to inhibit the sensation oftinnitus. This method has been shown to be effective,although it is not feasible for persons with severe toprofound hearing impairments because their hearingloss is too severe.

Cochlear implants (CI), which stimulate the cochleaelectrically, have been successful in restoring thehearing for severely and profoundly deaf individualsworldwide. Ito et. al. (1994b) has reported that 69%of patients experienced tinnitus suppression after apromontory stimulation test that involved electricalstimulation of the cochlear wall. Cochlearimplantation may also be effective in relievingtinnitus.

The purpose of this review was to evaluate theeffectiveness of CI’s on the suppression of tinnitus.The research that has been done on the topic to dateconcentrates specifically on adults. Althoughchildren with sensorineural hearing loss also exhibitsignificant amounts of tinnitus, reports are difficult toobtain from this population. The measurement oftinnitus is purely subjective and such reports havebeen unattainable from children (Ruckenstein, 2001).

Objectives

The primary objective of this paper was to criticallyevaluate existing literature regarding the suppressionof tinnitus after cochlear implantation. The secondaryobjective was to propose evidence-based practicerecommendations for clinicians regarding patientcounseling and informed consent.

Methods

Search StrategyComputerized databases, including Medline andComDisDome, were searched using the followingsearch strategy:

(tinnitus) AND (cochlear implant).

The search was limited to articles written in Englishbetween 1991 and 2005.

Selection CriteriaStudies selected for inclusion in this critical reviewpaper were required to investigate the effectivenessof cochlear implantation on the reduction of tinnitusin adult patients who were severely to profoundlyhearing impaired. Patients involved in these studieswere those who were candidates for CI’s, allowing usto look at both pre-implantation tinnitus and theeffects of post-implantation.

Data CollectionResults of the literature search yielded cross-sectionaland prospective and retrospective cohort studiescongruent with the aforementioned selection criteria.

Results

The literature articles were each thoroughlyexamined, and their methodological strengths andweaknesses were appraised. It is important todetermine an article’s worth before accepting any of

DO COCHLEAR IMPLANTS PROVIDE SIGNIFICANT REDUCTION IN TINNITUS LEVELS IN ADULT PATIENTS?

its results. To conclude that an article is in fact valid,the methodology was examined for subject selectionmethods, study design, instrumentation used, and themethod of data analysis.

There are no generally accepted, standardizedoutcome measures of reporting the degree of tinnitus.Each study used a different form of an un-standardized questionnaire to report on tinnitusseverity, which made it difficult to compare resultsbetween studies. Each study was therefore reviewedseparately and results were looked at individually.With the exception of a few studies, there wasusually a lack of information provided regarding theformulation of the questionnaire, and there was oftenno mention of how it had been administered to thepatients. The construct validity of such studies wastherefore poor.

The construct validity of the study by Ito (1994a), aswell as Tyler (1995) is questionable. In these studiestwo different questionnaires were administered atdifferent time frames throughout the study. Thisreduces the consistency in data collection, and anyconclusions regarding tinnitus change pre- and post-implantation cannot be confidently made.

The advantage of having a written questionnaire isthat written forms are standardized so that everyoneis exposed to the same questions in the same way,thereby reducing bias from interactions with aninterviewer.

All studies used convenience sampling to select theirsample population. Subjects were selected based ontheir presence in a CI program in a particular facility.Although the use of convenience sampling wasunavoidable in the research design, it allowed for agreater sample size. The number of participantsincluded in the studies ranged from 6 to 84. Randomsampling may have reduced this number further.

The research articles used some form of a non-experimental study design. Subjects were notassigned to different groups in this type of design.Instead, the same subjects were followed over a shortperiod of time and compared on one commonvariable (in this case: the severity of tinnitus). It isimportant to note that because the same individualswere tested throughout the study, personalcharacteristics remained relatively constant.

Tinnitus reduction post-implantationSouliere et. al. (1992) quantified changes in tinnitusafter cochlear implantation of the Nucleus CI. Datafrom the twenty-eight patients, who experienced

tinnitus pre-implantation, was collected using self-report questionnaires. Twenty (77%) of the patientsexperienced a decrease or complete elimination oftinnitus in the ipsilateral ear and a 42% decreasecontralaterally. Unlike some of the other studies,where the patients were only questioned regardingtheir presence of tinnitus, Souliere used a 10 pointlinear scoring system for the tinnitus questions. This10 point scale allows for a better quantification oftinnitus change rather a more binary (yes/no)outcome. The results were statistically analyzed andfound to have significance in the decrease of tinnitusloudness and annoyance post-implantation.

Another study by Mo et. al. (2002) found a 54% (32out of 59 patients) improvement in patients whoexperienced pre-operative tinnitus. This study hadused control groups of non-cochlear implant patientsas well as hearing aid users as a means ofcomparison. The use of control groups in the studydesign further increases the validity of the results.

Both Souliere (1992) and Mo (2002) included in theirpurpose the effect of confounding variables ontinnitus suppression. Such variables as age, gender,cause of hearing loss, tinnitus duration, and healthwere accounted for in the studies. It was determinedthat these factors did not significantly contribute totinnitus suppression after implantation.

Of the eight reviewed studies, Souliere (1992), Mo(2002), and Tyler (1995) had superior study designswhich provided enough knowledge for studyreplication for the future. In these studies, datacollection procedures were described in a clear anddetailed manner that would allow replication. Theself-report questionnaires used were either outlinedwith sufficient detail or referenced adequately by theresearchers.

Worsening of tinnitusIn addition to tinnitus suppression in cochlearpatients, there have also been reports of theworsening of tinnitus post-implantation in themajority of the reviewed literature. Results show thatthis is a rare occurrence, appearing in roughly 1%-8%of those involved in these studies. Although rare, thisis a significant finding when obtaining informedconsent from cochlear implant candidates.

Tyler (1995), Ito (1997) and Souliere (1992) allreported some degree of aggravated tinnitus in theirpatients after implantation, although suppression wasevident in a 2-24 month follow up. The remainder ofthe literature did not follow their patients over a

DO COCHLEAR IMPLANTS PROVIDE SIGNIFICANT REDUCTION IN TINNITUS LEVELS IN ADULT PATIENTS?

significant amount of time to observe any changes intinnitus.

Conclusions

The majority of the studies reported that a significantnumber of implantees exhibited a lessening oftinnitus after cochlear implantation. Whencounseling patients, based on this research, it issignificant to mention the added benefit that cochlearimplants provide in the reduction of tinnitus.

There were a number of trends evident regarding theeffect of cochlear implantation on tinnitus:

• Reduction of tinnitus intensity andannoyance were observed

• Risk of worsening of tinnitus postimplantation

• Both ipsilateral and contralateral reductionin tinnitus

• Long-term effectiveness of CI on tinnitusreduction

Further research should be conducted with regards tothe worsening of tinnitus, as well as any long-termeffects that CI’s may have on tinnitus. Such researchwould provide clinicians with useful counseling toolsfor the cochlear implant candidate.

The risk of tinnitus worsening post-implantation hasbeen documented, and although it is a rare finding itis of clinical importance. It becomes relevant, whenobtaining informed consent from a patient, to statethe researched benefit that cochlear implantation mayhave on reducing tinnitus and any possibility of thedevelopment/worsening of tinnitus.

Further research needs to be done to examine thelong-term effects of CI’s on tinnitus suppression.The small number of studies that found aggravatedtinnitus in a small percentage of their patients notedthat the condition of tinnitus changed (alleviatedtinnitus) over time after the surgery.

Although limitations were evident in some of thestudy designs, they were not so great that deemed thefindings to be inconclusive. The combined evidenceincluded in this review is strong enough to concludethat CI’s do provide some suppression of tinnitus inthe adult population.

References

Eggermont JJ, Roberts LE. The neuroscience oftinnitus. Trends Neurosci. 2004 Nov;27(11):676-

82. Review.Ito J, Sakakihara J. Suppression of tinnitus by

cochlear implantation. Am J Otolaryngol.1994(a) Mar-Apr;15(2):145-8.

Ito J, Sakakihara J. Tinnitus suppression by electricalstimulation of the cochlear wall and by cochlearimplantation. Laryngoscope 1994(b);104:752-4

Ito J. Tinnitus suppression in cochlear implantpatients. Otolaryngol Head Neck Surg. 1997Dec;117(6):701-3.

Mo B, Harris S, Lindbaek M. Tinnitus in cochlearimplant patients--a comparison with otherhearing-impaired patients. Int J Audiol. 2002Dec;41(8):527-34.

Osaki Y, Nishimura H, Takasawa M, Imaizumi M,Kawashima T, Iwaki T, Oku N, Hashikawa K,Doi K, Nishimura T, Hatazawa J, Kubo T.Neural mechanism of residual inhibition oftinnitus in cochlear implant users. Neuroreport.2005 Oct 17;16(15):1625-1628.

Ruckenstein MJ, Hedgepeth C, Rafter KO, MontesML, Bigelow DC. Tinnitus suppression inpatients with cochlear implants. Otol Neurotol.2001 Mar;22(2):200-4.

Souliere CR Jr, Kileny PR, Zwolan TA, Kemink JL.Tinnitus suppression following cochlearimplantation. A multifactorial investigation.Arch Otolaryngol Head Neck Surg. 1992Dec;118(12):1291-7.

Stouffer JL, Tyler RS. Characterization of tinnitus bytinnitus patients. J Hearing Speech Dis.1990;55:439-453.

Tyler RS. Tinnitus in the profoundly hearing-impaired and the effects of cochlear implants.Ann Otol Rhinol Laryngol Suppl. 1995Apr;165:25-30.

Copyright @ 2006, Charette, C.

Critical Review:Do speech impairments alone negatively impact literacy development?

Charette, C.M.Cl.Sc. (SLP) Candidate

School of Communication Sciences and Disorders, U.W.O

This critical review examines whether speech impairments in the preschool yearsnegatively impact literacy development and if so, what recommendations can be made topracticing speech-language pathologists. The research studies include longitudinal,prospective and cross-sectional designs. Based on the critical review, there isinconclusive evidence as to whether children with speech impairments alone will havedifficulties with literacy development. Further research needs to be conducted in order toobtain more consistent results that will inform professionals what to communicate toparents of preschool children with speech impairments about future literacy development.

Introduction

In recent years, the importance of early identificationof children with speech and language impairmentshas been emphasized. Clinicians and scientists seekto identify which children are at risk for particularimpairments and provide them with appropriateintervention in order to prevent further difficulties.Speech impairments are the most prevalentcommunication difficulty observed in young children(Lewis, Freebairn & Taylor, 2000). One issue thathas become a concern in the field of speech-languagepathology is the relationship between speechimpairments and literacy development.

Many different terms for speech impairments areused in the literature. The terms speech impairment,articulation disorder, speech sound disorder,articulation impaired, and expressive phonologydisorder are all used to describe “physically normalchildren who do not produce the full range ofphonemes of their native language at an age whenmost children have acquired this ability, despite themdeveloping normally in all other respects” (Bird,Bishop & Freeman, 1995, p.447). Literacy is a termused to encompass multiple aspects of academics. Itcan be defined as “the process by which oneconstructs meaning from printed symbols” (Larson &McKinley, 2003, pg.83). Adequate phonology skillsmay be seen as a necessary component for literacyacquisition because decoding of words requireschildren to sound out the letters. If the phonologysystem is disordered, this may be a difficult task forthese children. Literacy difficulties can have animpact on the child’s academic, social and emotionalsuccess.

The relationship between speech impairments andliteracy development is important to understandbecause early identification of risk for literacy

problems (if any) in children with speechimpairments could prevent the onset of literacyproblems. In addition, parents could be given aninformed explanation of what to expect in the futurewhen their child enters school.

Objectives

The primary objective of this paper is to criticallyevaluate the existing literature that examines theimpact of speech impairments on literacydevelopment. The secondary objective is todetermine an appropriate recommendation forclinicians in the practice of speech-languagepathology.

Methods

Search StrategyThe research articles were found using acomputerized database search, including CINAHL,PubMed and Medline. The following key terms andsearch strategies were used:

((phonolog* OR speech ORarticulat*) AND (impairment* OR disorder*OR delay* OR disabilit*) AND (literacy ORacademic* OR read* OR spell* OR writtenOR writing)).


Selection CriteriaThe studies that were selected for this critical reviewpaper examined the relationship between any speechdisorder and later literacy development. The studieswere not limited to outcome measures or thedemographics of the research participants.

THE IMPACT OF SPEECH IMPAIRMENTS ON LITERACY DEVELOPMENT

Data CollectionThe literature search identified ten studies that metthe above selection criteria. These consisted ofstudies employing longitudinal (8), prospective (1)and cross-sectional (1) designs.

Results

Of the ten studies examined for this critical literaturereview, five concluded that speech impairments didnot negatively impact literacy development (Lewis &Freebairn, 1992; Hesketh, 2004, Catts, 1993; Bishops& Adams, 1990; Lewis, Freebairn, & Taylor, 2000).

Lewis and Freebairn (1992) conducted a study usinga cross-sectional design to examine the performanceof people with histories of preschool phonologydisorders on measures of reading, phonology andspelling across different age groups (i.e., preschool,grade school, adolescence, and adulthood). Theresearchers found that individuals with phonologyproblems alone did not demonstrate later readingdifficulties.

Lewis et al. (2000) hypothesized that children with anisolated phonology disorder would demonstrate betterlanguage and achievement outcomes than childrenwith phonology disorders accompanied by otherlanguage disorders. They reported that children withphonology disorders had significantly betteroutcomes in reading than those with both languageand phonology disorders (p.05).

Hesketh (2004) examined the literacy andphonological awareness skills at 6 to 7 years of age inchildren with a history of a speech disorder. Theresults indicated that children with histories of speechdisorders made good progress in speech and showedage appropriate literacy development. There were no

statistical analyses conducted in this study, limitingthe strength of the findings. Comparisons were madebetween the standard scores in the phonologysubtests and the reading subtests.

Five of the reviewed studies concluded that preschoolspeech impairments do put children at risk for laterliteracy difficulties (Larrivee & Catts, 1993; Nathan,Stackhouse, Goulandris, & Snowling, 2004; Bird,Bishop, & Freeman, 1995; Leitao & Fletcher, 2004;Raitano, Pennington, Bruce, Tunick, Boada &Shriberg, 2004).

Larrivee and Catts (1993) examined the relationshipbetween expressive phonological disorders and earlyreading achievement. They also examined whethervariability in reading achievement was related toindividual differences in expressive phonology. Theresearchers found that the phonologically disorderedgroup performed significantly less well than thephonologically normal group (p


compared to those with developmental speechimpairments.

Raitano et al. (2004) compared the pre-literacy skillsof children with speech impairments to those ofchildren with speech impairments and languagedisorders combined and children with no history ofspeech and language difficulties. Results revealedthat the entire group with speech impairments aloneperformed less well than control participants onphonological awareness and letter knowledge tasks.

Overall, six of the ten papers had the ability toanswer their research question based on themethodologies and designs used. Three of the soundstudies agreed with the research question and threedid not. Many of the studies used longitudinaldesigns, which was suitable because in order toanswer the research question the researchers wererequired to measure changes over a period of time.However, some authors experienced difficulties inusing a longitudinal design. Bird et al. (1995)indicated that it was not possible to follow all controlchildren so a different matched control group wasrecruited for each phase of testing; this may haveimpacted the results because the researcher may havefound a different outcome if the original controlgroup was used. Participant demographics were notwell controlled in all of the studies. Many of thestudies included more boys than girls, making it moredifficult to generalize to all children with speechdisorders. Some studies did not include a controlgroup of normally developing peers (Lewis &Freebairn, 2000; Bird et al., 1995; Leitao & Fletcher,2004; Hesketh, 2004; Bishops & Adams, 1990). Inorder to adequately examine the impact of purephonological impairments on literacy, a control groupof normally developing peers should have beenincluded in order to determine the base rate ofliteracy problems, which would allow the researchersto adequately compare literacy development amongthe two groups.

Six of the ten papers used appropriate standardizedmeasurement tools and statistical analyses given theresearch question and the number of variablesinvolved (Lewis & Freebairn, 1992; Lewis et al.,2000; Larrivee & Catts, 1999; Nathan et al., 2004;Bird et al., 1995; Raitnao et al, 2004). Lewis andFreebairn (1992) used a paired t-test to examinedifferences between the experimental and controlgroup, which may be a more powerful statisticalanalysis compared to an independent sample t-testbecause individual variability is better controlled.

Leitao and Fletcher (2004) used age equivalent scoresfor their analysis instead of standard scores. Ageequivalent scores are not as reliable as standardscores because they do not represent equal intervalsacross the range of scores or include a measure ofnormal variation.

Across the studies, the researchers’ interpretations oftheir statistical analysis were appropriate. Theresearchers discussed the limitations of their studiesand, for those studies that found that speechimpairments do put children at risk for later literacyproblems, indicated that speech impairments are onlyone of the variables or risk factors that impact achild’s literacy achievement.

Recommendations

Although the available literature on the relationshipof speech impairments and later literacy developmentis inconsistent, some recommendations can be madefor clinicians working with this population.Clinicians can inform parents that, although there isno direct support that children with speechimpairments will most certainly have difficulties withliteracy development, there is still a chance that thesechildren may be more at risk for literacy problemsthan their peers who do not have speech impairments.Some of the rigorous studies provided evidence thatthese children do have difficulty with some literacytasks. Therefore, clinicians and teachers should bemade aware of children who had preschool speechimpairments and monitor them as they acquireliteracy skills.

Conclusion

A critical review of the literature has demonstratedthat there is inconclusive evidence to suggest thatspeech impairments directly have a negative impactfor future literacy development. However, there issome research that indicates that these children maybe at risk for literacy difficulties and should beclosely monitored.

In order to make better recommendations for teachersand clinicians, future research should focus moreclosely on several variables. First, researchers shouldexamine and control for the types of speechimpairments (i.e., phonological processes vs.developmental errors) in their samples. Second,severity of speech impairment should be consideredin order to determine if severity predicts who is atgreater risk for literacy problems. Lastly, somestudies indicated that children who have speechimpairments that persist into the school years had


more difficulties with literacy than those childrenwhose speech impairments had resolved. Morestudies should address the persistence of speechimpairments into grade school and how they impacton literacy development. By focusing future researchon these variables, researchers can determine whichchildren are most at risk for developing literacyproblems in the future and appropriate support can beimplemented by teachers, parents and clinicians.

References

Bird, J., Bishop, D.V.M., & Freeman, N.H. (1995).Phonological awareness and literacydevelopment in children with expressivephonological impairments. Journal of Speechand Hearing Research, 38, 446-462.

Bishops, D.V.M., & Adams, C. (1990). A prospectivestudy of the relationship between specificlanguage impairment, phonological disordersand reading retardation. Journal of ChildPsychology and Psychiatry, 31, 1027-1050.

Catts, H.W. (1993). The relationship between speech-language impairments and reading disabilities.Journal of Speech and Hearing Research, 36,948-958.

Hesketh, A. (2004). Early literacy achievement ofchildren with a history of speech problems.International Journal of Language andCommunication Disorders, 4, 453-468.

Larrivee, L.S., & Catts, H.W. (1999). Early readingachievement in children with expressivephonological disorders. American Journal ofSpeech-Language Pathology, 2, 118.

Larson, V.L., & McKinley, N. L. (2003).Communication Solutions for Older Students:Assessment and Intervention Strategies. EauClaire, WI: Thinking Publications.

Lewis, B. A., & Freebairn, L. (1992). Residualeffects of preschool phonology disorders ingrade school, adolescences, and adulthood.Journal of Speech and Hearing Research, 35,819-831.

Lewis, B. A., Freebairn, L.A. & Taylor, H.G. (2000).Follow-up of children with early expressivephonology disorders. Journal of LearningDisabilities, 5, 433-444.

Leitao, S., & Fletcher, J., (2004). Literacy outcomesfor student with speech impairments: long-termfollow-up. International Journal ofCommunication Disorders, 39, 245-256.

Nathan, L., Stackhouse, J., Goulandris, N., Snowling,M.J., (2004). The development of early literacyskills among children with speech difficulties: Atest of the “critical age hypothesis”. Journal of

Speech, Language, and Hearing Research, 47,377.

Raitano, N.A., Pennington, B.F., Tunick R.A.,Boada, R., & Shrilberg L.D. (2004). Pre-literacyskills of subgroups of children with speechsound disorders. Journal of Child Psychologyand Psychiatry, 45, 821-835.

Copyright © 2004 by Greene, S.E.

Critical Review:The Effectiveness of PECS on the Development of

Communication in Children with Autism Spectrum Disorders

Greene, S.E.M.Cl.Sc. (SLP) Candidate


This critical review examines the effects of the Picture Exchange Communication System(PECS) on the development of communication in children with autism spectrumdisorders (ASD). Study designs include: quasi-experimental, multiple baseline,alternating treatments, retrospective and prospective designs. Overall, the availableresearch makes generally positive conclusions about the effectiveness of PECS as a modeof communication for children with ASD, however further research is suggested in orderto more systematically evaluate the impact of this treatment.

Introduction

Children with autism spectrum disorder (ASD) oftenexperience serious receptive, expressive andpragmatic communication difficulties (Dooley,Wilczenski, & Torem, 2001). It is important to note,that “communication” involves all of the areasmentioned above, and may be defined as, “any act bywhich one person gives to or receives from anotherperson, information about that person’s needs,desires, perceptions, knowledge, or affective states.Communication may be intentional or unintentional,may involve conventional or unconventional signals,may take linguistic or nonlinguistic forms, and mayoccur through spoken or other modes,” (Beukelman& Mirenda, 1998). Difficulties with these areas ofcommunication may affect a child’s ability to interacteffectively, making intervention of communicationdeficits a top priority for families and clinicians(Bondy & Frost, 1994; Charlop-Christy, Carpenter &LeBlanc, 2002; Schwartz, Garfinkle & Bauer, 1998).An option for children with communicationdifficulties is an augmentative and alternativecommunication (AAC) system.

An AAC system is an integrated group ofcomponents, including the symbols, aids, strategiesand techniques used by individuals to enhancecommunication (Beukelman & Mirenda, 1998).When used by persons with disabilities to replace orsupplement insufficient communication skills, AACsystems have been shown to be a successful languageintervention (Ganz & Simpson, 2004; Kravits,Kamps, Kemmerer & Potucek, 2002). AAC systemsgive individuals with autism a method for expressingpersonal choice and preference in the absence ofverbal language that may be difficult, if notimpossible, for them to produce with mastery (Frea,Arnold, & Vittimberga, 2001).

One picture-based AAC method used frequently forintervention with children with ASD is the PictureExchange Communication System (PECS) (Ganz etal., 2004). PECS was developed by Bondy and Frost(1994) for use with children with social-communication deficits. PECS simultaneouslyteaches initiation of wants and needs and providesverbal models of language (Kravits et al., 2002).PECS uses a more naturalistic teaching approach thanmany other types of intervention becausecommunication is initiated by the child rather thancontrolled by adult verbal cues (Kravits et al., 2002).Pictures are kept by the child on a “PECS board” andthe child is instructed to use his or her PECS board toconstruct a “sentence” by selecting picture cards andbringing the cards to a communicative partner torequest the desired item (Charlop-Christy et al.,2002). PECS is organized into stages that initiallyrequire the child to practice exchanging the PECSsymbols with an adult and eventually with his or herpeers.

PECS is based on a number of key conceptsregarding individuals with ASD and how they learnlanguage and social interaction skills (Ganz et al.,2004). Unlike many traditional programs targetingincreased verbal output such as sign language, whichfirst requires children to attain attending skills (e.g.eye contact), PECS does not require training in suchprerequisites. Additionally, while traditional speechprograms often begin by teaching students to respondto verbal prompts, PECS teaches a social approach, akey area of deficit in ASD. Finally, while manycommunication techniques begin by teachingchildren to label, requesting is taught in the PECSprogram because it is rewarded and maintained byconcrete reinforcement such as food and toys (Ganzet al., 2004).

THE EFFECTIVENESS OF PECS ON THE DEVELOPMENT OF COMMUNICATIONIN CHILDREN WITH AUTISM SPECTRUM DISORDERS

Regardless of its logical design and foundation inapplied behaviour analysis, support for PECS islargely subjective in nature. Few publishedexperimental studies have addressed the efficacy ofPECS or its ability to stimulate speech when usedwith children with ASD (Charlop-Christy et al.,2002; Ganz et al., 2004; Kravits et al., 2002; Magiati& Howlin, 2003; Schwartz et al., 1998). Despite thelimited data on the efficacy of PECS, it is usedwidely in schools and treatment centers (Ganz et al.,2004).

Objectives

The primary objective of this paper is to criticallyevaluate existing literature regarding theeffectiveness of PECS on the development ofcommunication for children with ASD. Thesecondary objective is to propose evidence-basedpractice recommendations about the use of PECS inthis population and areas for future research.

Methods

Search StrategyComputerized databases, including PubMed, Web ofScience and PsycInfo were searched using thefollowing search strategy:

((autism) OR (autistic*) OR (ASD) OR(autism spectrum disorder*)) AND ((PECS)OR (picture exchange communicationsystem) OR (AAC) OR (augmentative andalternative communication)).

The search was limited to articles written in English.

Selection CriteriaStudies selected for inclusion in this critical reviewpaper were required to investigate the impact ofPECS based therapy on communication outcomes forchildren with ASD. No limits were set on thedemographics of research participants or outcomemeasures.

Data CollectionResults of the literature search yielded the followingtypes of articles congruent with the previously statedselection criteria: quasi-experimental (3), multiplebaseline design (2), alternating treatment design (2),and a design with both retrospective and prospectivecomponents (1).

Results

Impact of PECS on CommunicationGanz et al. (2004) investigated the role of PECS inimproving the number of words spoken, increasingthe complexity and length of phrases and decreasingthe occurrence of non-word vocalizations. It wasfound that after teaching three children with autismphases 1-4 of PECS, their utterances increased innumber of words and complexity of grammar.

Communicative output was also examined in a studyby Magiati et al. (2003). In this study, 34 childrenwith ASD improved in their PECS vocabulary andthe majority of these children also slowly showedimprovements in their general communication.

Charlop-Christy et al. (2002) explored the acquisitionof PECS in three children with autism. All childrenshowed increases in verbal speech as well as gainsassociated with increases in social communicativebehaviours.

A case study of a six-year old girl with autismindicated that the introduction of PECS increased herspontaneous language (requests and comments)including the use of icons and verbalizations acrossthe settings in which PECS was taught (Kravits et al.,2002). Intelligible vocalizations increased in two ofthe three settings in which PECS was implementedand changes in peer social interaction were alsonoted.

Liddle (2001) also looked at changes incommunicative output in children with autism whowere trained in each of the PECS stages. For 15children with autism or severe learning disabilities, itwas found that all except one learned to use PECS torequest. Forty-two percent of these children showedincreases in their attempts at spoken language and33% attempted single words.

Tincani (2004) compared PECS versus sign languagein two students with autism. One participantacquired more mands (requests for preferred items)using sign language while the other participantacquired more mands using PECS. However, it wasfound that for both participants, using sign languagewas associated with more vocalizations.

A final study that looked at communicative output inits participants was conducted by Cummings et al.(2000). The authors found that the children learnedto imitate simple sounds within a few sessions afterdemonstrating mastery on PECS.


Acquisition of PECSGanz et al. (2004) and Schwartz et al. (1998) notedthat children with autism were able to learn PECSquickly and effectively. Magiati et al. (2003) foundthat the children with ASD improved in the level ofPECS attained as well as increased their frequency ofPECS use over time. The majority of these childrenalso showed improvements in their ability to usePECS. In the study by Charlop-Christy et al. (2002),all children met the learning criterion for PECS,which was 80% correct for each PECS phase.

Generalization of PECSA final element of PECS training in children withautism is generalization. By taking language samplesduring snack time and free time, Schwartz et al.(1998) suggested that PECS generalizes to untrainedsettings and may have effects on untrained languagefunctions.

Analysis of Results and InterpretationsThe above studies made generally positiveconclusions about the effectiveness of PECS on thedevelopment of communication in children withASD. However, the ability of these studies to answerthis question and the hypotheses stated in each articleis limited when the methods, study designs and use ofstatistical analyses are taken into consideration.

Three of the above studies should be interpreted withmuch caution as they did not include baselinemeasures, controls or statistical analyses (Ganz et al.,2004; Liddle, 2001; Schwartz et al., 1998). Thesestudies were not able to account for whether or notchanges were due to treatment or to maturation overtime. An additional concern with the study by Liddle(2001) was that ages of the subjects was not reported,which makes it difficult to generalize the results to aspecific population. A positive aspect about thestudies by Liddle (2001) and Schwartz et al. (1998)was that larger sample sizes of 21 and 31 childrenrespectively, were used.

Studies by Charlop-Christy et al. (2002), Cummingset al. (2000) and Tincani (2004) had moderateproblems because they all collected baselinemeasures but did not use statistical analyses. Anotherconcern with these three studies was the small size ofthe samples, which ranged from two to five. Oneparticular limitation of the study by Tincani (2004)was that the participants did not receive therecommended number of communicationopportunities during PECS training as suggested byBondy and Frost, which may have limited theiracquisition of PECS.

Minor limitations were evident in the study byMagiati et al. (2003) because multiple baselinemeasures were not collected but statistical analyseswere applied. Another particular problem with thestudy by Magiati et al (2003) was that the outcomemeasures that were used relied almost entirely onrating scales and questionnaires completed byteachers and parents. There was no objectiveassessment of the children’s communicative andcognitive abilities and it is possible that ratings mayhave been influenced by expectations of staff andparents rather than actual changes. Similarly, minorproblems were found in the study by Kravits et al.(2002) because baseline measures were collected andstatistical analyses were conducted but possibleeffects of co-occurring treatments were notcontrolled. Specifically, social skills booster sessionstook place at the time of treatment, which may havehad an impact of the children’s acquisition of PECS.It was unclear what social effects were from PECSalone, and which may have been from the socialskills booster sessions (Kravits et al. 2002). A largersample size of 34 children was reported in the studyby Magiati et al. (2003) compared to the number ofparticipants in the study by Kravits et al. (2002),which was only one.

Recommendations for Future Research

In order to address the above-mentionedconcerns related to study designs and statisticalanalyses, there is a need for future research. First,future research should include controls. It would beappropriate to have the children act as their owncontrols, thus avoiding the ethical issues ofwithholding treatment in a control group. Second,future research should include baseline measures inorder to determine the amount of change pre-treatment compared to post-treatment. It is importantthat it is determined whether the changes observedare due to treatment or simply due to maturation.Third, thorough statistical analyses are recommendedin order to determine significance of change and thedifference in the children’s abilities at various pointsthroughout treatment. Finally, future research shouldkeep treatment fidelity issues in mind as it appearsthat PECS is not always implemented in a way that isconsistent with the procedures outlined in the PECSmanual by Bondy and Frost.

Recommendations for Clinical Practice

The literature examined provides information that isdirectly relevant to clinical practice. First, it isimportant that speech-language pathologists informparents that PECS is not intended as a way to teach


children to learn how to speak. Instead, PECS istaught in order to teach children functionalcommunication skills and the acquisition of speechcan be viewed as a wonderful by-product of theapproach, rather than its direct focus (Tincani, 2004).Parents can be told that the literature supports the useof PECS as a mode of communication and that thespeech output of children with ASD often increasedas well. It can also be mentioned to parents thatliterature relating to PECS having a negative impacton communicative output has not been encounteredduring this review.

Second, it is important that speech-languagepathologists monitor the child’s progress whilelearning PECS using objective measures (such as asingle-subject multiple baseline design) and employanother means of communication (e.g., signlanguage) if the child does not seem to be makinggood progress with PECS.

Conclusions

The information that has emerged about thistreatment approach looks promising. Uponexamination of the results of the reviewed studies, itis evident that future research in the area of PECS asa treatment approach for children with ASD isnecessary to continue to build on the previouslymentioned conclusions and fill in any gaps in theresearch. In particular, concerns related to studydesigns and statistical analyses should be addressedin order to more systematically evaluate the impact ofthis treatment. Based on the existing research, it issuggested that PECS may be a beneficial mode ofcommunication for certain children with ASD.

References

Beukelman, D. & Mirenda, P. (1998). Augmentativeand alternative communication, 2nd edition.Baltimore: Paul H. Brookes Publishing Co.

Bondy, A. & Frost, L. (1994). The picture exchangecommunication system. Focus on AutisticBehaviour, 9(3), 1-19.

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Copyright © 2006 by Grigg, D.M.

Critical Review:The Efficacy of Peer-Mediated Intervention for Increasing Social Functioning

of Children With Autism

Grigg, D.M.M.Cl.Sc. (SLP) Candidate


This critical review examined the effects of peer-mediated intervention on the socialfunctioning of children with autism. In particular, studies were examined in which peerswere trained as therapy agents. Study designs included: pretest-postest with control,single-subject reversal, and single-subject repeated measures designs. Overall, researchsuggests that peer-mediated intervention may have some positive effects on the socialskills of children with autism, including improvements in both quality and quantity ofsocial interactions. However, there are some weaknesses in the quality of the research inthis area and results should be interpreted with caution.

Introduction

One of the most salient characteristics exhibited byindividuals with autism is a deficit in socialfunctioning (Rogers, 2000). For this reason,intervention for children with autism has placedconsiderable focus on improving the social skills ofthese children. Various interventions have been usedin the past, with primary emphasis on adult-directedprocedures. While these adult-directed interventionshave been somewhat effective in improving socialskills during treatment, questions have arisenconcerning the artificial context of this type ofintervention (Shafer, Egel & Neef, 1984). As aresult, professionals in the field of autism have begunto turn towards social skills interventions that involvethe peers of children with autism, rather than adultdirection. These peer-mediated interventions areconsidered to be more naturalistic and perhaps moreeasily generalized to the child’s daily environment(Rogers, 2000).

Peer-mediated interventions require training of same-age peers by skilled professionals. Peers are firsttaught ways to initiate and maintain interactions withchildren who have social impairments. Once thepeers have been sufficiently trained, they are placedin social situations with children with autism and areasked to use the trained skills (Goldstein, Kaczmarek,Pennington, & Shafer, 1992). In most peer-mediatedinterventions, adults are generally involved to someextent in order to monitor the children’s interactions,and to provide reinforcement or reminders whennecessary (Rogers, 2000).

Objectives

The primary objective of this paper is to criticallyevaluate existing literature regarding the efficacy ofpeer-mediated intervention for improving thequantity and quality of social interactions of childrenwith autism. Specifically, peer-mediatedinterventions utilizing trained peers as the therapyagents will be examined. The secondary objective ofthis paper is to propose evidence-based practicerecommendations concerning the use of such anintervention for children with autism.

Methods

Search StrategyComputerized databases, including Web of Scienceand Psychinfo, were searched using the followingsearch strategies:

1. ((social interactive training) OR (peer-mediated intervention) OR (social skillstraining)) AND ((Autism) OR (Autistic*))

2. (social skills) AND (intervention) AND(peers) AND ((Autism) OR (Autistic*)).


Selection CriteriaAll of the studies selected for inclusion in this criticalreview paper investigated the impact of peer-mediated intervention of the social functioning ofchildren with autism. In addition, all studies usedpeer-mediated interventions in which peers weretrained and functioned as the therapy agents. Thesestudies were not limited to specific participantdemographics or outcome measures.

THE EFFICACY OF PEER-MEDIATED INTERVENTION FOR INCREASING SOCIAL FUNCTIONING OF CHILDREN WITH AUTISM

Data CollectionResults of the literature search yielded the followingten quantitative, prospective studies examiningtreatment outcome: pre-test, post-test with controldesigns (2), single-subject reversal designs (2), andsingle-subject repeated measures designs (6).

Results

OutcomesOf the ten studies reviewed in this paper, eightreported positive outcomes for the use of peer-mediated intervention to increase social functioningof children with autism (Goldstein, Kaczmarek,Pennington and Shafer, 1992; Kalyva & Avramidis,2005; Kamps, Potucek, Lopez, Kravitz, &Kemmerer, 1997; Laushey & Heflin 2000; McGrath,Bosch, Sullivan, & Fuqua, 2003; Pierce &Schriebman, 1995, Pierce & Schriebman, 1997,Shafer, Egel, & Neef, 1984).

Kalyva and Avramidis (2005) used a pre-test, post-test with control design to investigate the effects oftraining and using a peer group to administer socialskills intervention for children with autism.Preschool subjects with autism were randomlyassigned to experimental and control groups. Anappropriate non-parametric statistic (i.e., Mann-Whitney test) was used to analyze the data. Theauthors concluded that children in the experimentalgroup displayed significantly greater response andinitiation rates following intervention. However, theauthors made only one, one-hour observation of thechildren’s social skills at each stage of research (i.e.,baseline, intervention, post-intervention). This maynot have been enough observation points to obtainreliable data on changes in social behaviours.

Two studies used a single-subject reversal design(Goldstein et al., 1992; Laushey & Heflin 2000) toexamine the effects of peer-mediation for targetingthe social skills of children with autism. Statisticswere not used in either of these studies. However,both articles used appropriate multiple baselinedesigns. Social behaviours were observed untilstable before moving to the next stage of the study.Goldstein et al. (1992) reported increases in theamount of time children with autism spent ininteractions following intervention, as well asincreased responsiveness to peers after intervention.However, the authors reported a lack of reversal tobaseline for one child. This may suggest that therewere either carry-over effects of intervention, or thatchanges in behaviour for this participant were not dueto the intervention. Laushey and Heflin (2000)

concluded that peer-mediated intervention improvedboth initiating and maintenance of social interactionsby children with autism. This study also reportedincreases in turn-taking following the intervention(Laushey & Heflin, 2000).

Five of the eight articles suggesting positiveoutcomes for the use of peer-mediated intervention(Kamps et al., 1997; McGrath et al., 2003; Pierce &Schriebman, 1995, Pierce & Schriebman, 1997,Shafer et al., 1984) used a single subject repeatedmeasures design. In these studies, participants servedas their own controls. None of these studies usedstatistical analyses. However, all five used a multiplebaseline design, which was appropriate fordetermining whether changes in behaviour were dueto treatment. Of these five studies, four reported thatpeer-mediated intervention resulted in increased timechildren with autism spent in social interactions(Kamps et al., 1997; McGrath et al., 2003; Pierce &Schriebman, 1995; Shafer et al., 1984) and twostudies reported increases in the frequency of theseinteractions (McGrath et al., 2003; Shafer et al.,1984). Following peer-mediated intervention, threeof these studies observed that children with autismdisplayed increased initiation with peers (McGrath etal., 2003; Pierce & Schriebman, 1995; Pierce &Schriebman, 1997) and two studies reportedimproved responding (McGrath et al., 2003; Pierce &Schriebman, 1997). In addition, increases incooperative and associative play (McGrath et al.,2003) and improved language engagement (Pierce &Schriebman, 1995) were noted for children withautism following intervention.

Despite these positive outcomes, some research hasfailed to find significant improvements in the socialskills of children with autism following peer-mediation. Using a single-subject repeated measuresdesign, Thieman and Goldstein (2004) found noremarkable changes in social skills following thisform of intervention. However, written text trainingwas introduced immediately following peer-mediatedintervention. As a consequence, the effects of peer-mediation and written text treatment on social skillspost-intervention and at follow-up could not bedifferentiated.

Roeyers (1996) also failed to find strong support forthe use of peer-mediated intervention. This studyutilized a pre-test, post-test with control design.Participants were matched by age and sex, and thenrandomly assigned to treatment or control groups.Non-parametric statistics for matched-subjects wereused to evaluate the data. However, children with

THE EFFICACY OF PEER-MEDIATED INTERVENTION FOR INCREASING SOCIAL FUNCTIONING OF CHILDREN WITH AUTISM

autism were reported to show no improvements ininitiating with peers following the intervention.

Generalization and MaintenanceIn general, research has shown maintenance ofimprovements in social functioning at follow-up forchildren with autism who received peer-mediatedintervention (Kalyva & Avramidis, 2005; Pierce &Schriebman, 1995; Shafer et al., 1984). However, thedata on generalization of these improvements insocial skills are less clear. While some studies havefound that improvements generalized to interactionswith other peers (Laushey & Heflin, 2000; Pierce &Schriebman, 1997; Roeyers, 1996) and in multiplesettings (Pierce & Schriebman, 1995; Roeyers, 1996),others reported that improvements in socialfunctioning were not consistently generalized(Kamps et al., 1997; Shafer et al., 1984). Shafer,Egel, and Neef (1984) stated that generalization ofimprovements in social functioning in their studyoccurred only after the children with autism receivedadditional specific programming.

Methodological WeaknessesThere were several major weaknesses worth noting inthe studies presently reviewed. First, several studiesused observers (i.e., authors) who were not blind tothe purpose of the study (Kalyva & Avramidis, 2005;Kamps et al., 1997; Laushey & Heflin, 2000;McGrath et al., 2003). In these cases, observations ofthe participants’ behaviours may have been biaseddue to prior knowledge of the hypotheses.

Secondly, with the exception of Roeyers (1996), allof the articles used small sample sizes ranging fromone to five participants. Such small sample sizeslimit the ability to generalize results to the largerpopulation.

Lack of control for confounding variables was also aweakness. One major confound in several studieswas the fact that target children with autism wereincluded in the peer training with their peers (Kampset al., 1997; Laushey & Heflin, 2000; McGrath et al.,2005; Shafer et al., 1984). As a result, behaviouralchanges in these studies cannot be said to be a resultof the peer-mediated intervention because thesechildren also received adult instruction.Additionally, though Roeyers (1996) co

communication sciences & disorders · broniewicz, a. 5 do speech impairments alone negatively...

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