LISTENERS'ATTITUDES: SPEECH SUPPLEMENTA TION STRATEGIES FOR IMPROVING EFFECTIVE NESS OF SPEAKERS WITH MIXED DYSARTHRIA AS A RESULT OF MOTOR NEURON DISEASE

This study examined unfamiliar and familiar listener attitudes towards the use of combined alphabet-topic cues and a control condition (habitual speech with no cues) associated with the speech of three individuals with severe mixed dysarthria. Two listenergroups (N=36) were shown experimentally imposed visual imagesofthecombinedalphabet-topiccuestrategyinconjunction with recorded auditory presentationswiththe habitual speech of three individuals with mixed dysarthria. Using a 7-point Likert scale, listeners were asked toratehoweffectivetheythoughtthespeakerscommunicated;howcomfortabletheywerecommunicating with the speakers; and how persistent they were in trying to understand the speakers. The results revealed thattherewerenosignificantdifferencesintheattituderatingsoffamiliarlistenersascomparedtounfamiliar listeners. However, resultsrevealedthatratingofcommunicativeeffectiveness, comfort communicatingwith speakers and listener persistence were each more favourable when using the combined cue condition than purelyhabitualspeech.Theresultssuggestthataugmentativeandalternativecommunicationstrategiesproviding frequent and specific cues regarding the content and constituent words of a message may enhance the attitudes of listeners.

lowing and breathing (Young 8cMcNicoll, 1998).The cause of M ND is unknown and is said to occur in 1.5 per 100,000 of the population worldwide with the average age of onset at 65 years and a greater incidence in males (Freed, 2000). Patients with M ND usually do not show any changes in cognitive abilities (Young 8cMcNicoll, 1998). The disorder is characterized by deficits in either the lower motor neuron or the upper motor neuron, but usually results from a com bination of both (Freed, 2000).
The type o f dysarthria that occurs in individuals with M ND depends on which motor neurons are affected. In the initial, mild stages, individuals with lower motor neuron in volvement will present with flaccid dysarthria, where as those with upper motor involvement present with spastic dysar thria. However, as the disease progresses to involve both the upper and lower motor neurons, patients will present with mixed dysarthria that will predominate throughout most of the disorder (Freed, 2000).
In a progressive neurological disorder such as MND, ap proximately 75% of the patients will reach a point where in telligible verbal communication is no longer possible (Freed, 2000). The rapid decline of speech function in patients with M N D is common, but is not inevitable. Mathy et al. (2000) identified and documented the progression o f dysarthria in individuals with M ND (Appendix A). In the early stage (Stage 1), there are no obvious deficits noticed in an indi vidual's speech, but as the disease progresses, the individu al's speech intelligibility becomes more compromised until at the final 5th stage, individuals with M N D lose all speech function.
Communication by nature requires the involvement of two communication partners who take turns playing the roles of the listener and speaker throughout the course o f in teraction (Hustad &. Beukelman, 2002). Speech intelligibil ity can be defined as the extent to which a spoken utterance is understood by the listener (Yunusova, Weismer, Kent 8c Rusche, 2005) and is seen as a significant factor in deter mining whether an individual is an effective communicator within a conversation (DePaul 8c Kent, 2000). Intelligibil ity is therefore a central concept in the field of speech-lan guage pathology, particularly for speakers with dysarthria, whose compromised intelligibility may impair their abili ty to communicate effectively in their daily lives (Hustad,Jones 8c Dailey, 2003).
Sentence intelligibility measures are often used for clini cal purposes such as quantifying the severity of dysarthria, measuring progress throughout the intervention process and in determining a speaker's communicative effectiveness (Hustad 8c Cahill, 2003). In addition, intelligibility meas ures are also used for basing decisions on the implementa tion of alternative and augmentative communication (AAC) strategies (DePaul 8c Kent, 2000).
Speech intelligibility is an interactive process that fluc tuates for any given speaker and is dependent on a host of variables pertaining not only to the speaker, but also to var iables associated with the listener and the communicative context (Hustad 8c Cahill, 2003). Relatively few o f these variables that are thought to have an influence on intelli gibility, have been systematically studied. However, recent research is beginning to demonstrate the importance of "signal-independent information" extrinsic variables on in telligibility (Hustad 8c Cahill, 2003). These extrinsic vari ables are not dependent on the acoustic signal produced by the speaker, but focus on factors that influence intelligibility for the listener.
The alphabet supplementation strategy involves the use of an alphabet board that speakers point to, to indicate the first letter of each word while simultaneously speaking it (Beukelman 8c Yorkston, 1977;Crow 8c Enderby, 1989;Hustad 8c Beukelman, 2001;Yorkston, Beukelman, Strand 8c Bell, 1999). This strategy aims to improve intelligibili ty by providing the listener with knowledge regarding the phonetic content of a word. In alphabet cues, the listener receives first-letter-of-word orthographic information that serves to limit the number of possible word choices and therefore improve the chances o f correct word identifica tion (Hustad, 2001a;Hustad 8c Beukelman, 2001;Hustad 8c Garcia, 2005). Several studies have demonstrated that al phabet supplementation can lead to sentence intelligibility scores that average approximately 35% higher than intelligi bility scores associated with habitual speech (Beukelman 8c Yorkston, 1977;Beukelman et al., 2000;Crow 8c Enderby, 1989;. W ith topic supplementation strategies, the use of a com munication board containing key words or phrases that rep resent topics or contexts in the speaker's life is used (Hustad, 2001a). Topics are represented orthographically or through the use of picture symbols. The speaker would point to the topic o f his/her message before producing it verbally (Beuke lman et al., 2002;Hustad, 2001b). Beukelman (2001,2002) suggest that this strategy assists the listener to narrow the expectations of the semantic content o f the mes sage. The topic supplementation strategy has been shown;to produce sentence intelligibility scores ranging from 3%' to 16% higher than habitual speech (Beukelman 8c Yorkston, 1977;Beukelman et al., 2002;Crow 8c Enderby, 1989;Hus tad et al., 2003).
The combined supplementation strategy involves the in tegration of both alphabet and topic supplementation strat egies. In this scenario, the speaker first presents the listener with a topic cue followed by a first-letter cue for each word spoken. This strategy has been shown to provide the high est sentence intelligibility scores, yielding as much as 35% to 40% higher scores than habitual speech (Beukelman 8c Yorkston, 1977;Beukelman et al., 2000;Crow 8c Enderby, 1989;.
The concept of 'attitude' has important social implica tions for individuals who use speech supplementation strat 64 | DIE SUID-AFRIKAANSE TYDSKRIF VIR KOMMUNIKASIE-AFWYKINGS, VOL. 5 5 ,2 0 0 8 Reproduced by Sabinet Gateway under licence granted by the Publisher (dated 2012.) egies to enhance their intelligibility. Attitudes have been a topic o f interest within the disability literature for the past five decades (Hustad 8c Gearhart, 2004).The widely accept ed notion of the AAC acceptance model states that attitude is a concept made up of three different components, namely affective, cognitive and behavioural components (Antonak 8c Livneh, 1988;Eiser, 1986;Greenwald, Brock 8c Ostrom, 1968;Lasker 8c Bedrosian, 2000;Triandis, Adamopoulos 8c Brinberg, 1984). The affective component of attitude in volves emotional and physiological reactions to AAC such as comfort level or frustration. The behavioural component relates to the willingness to use AAC or to interact with someone using AAC, whilst the cognitive component of at titude relates to both the speaker and partner's perceptions of communication skills (Hustad, 2001b).
The attitudes o f potential communication partners may be influenced by factors such as rate, intelligibility, personali ty characteristics and their view on disability. These attitudes in turn, may impact on a speaker's desire or motivation to adopt one o f the previously mentioned speech supplemen tation strategies and hence provides valuable information to support clinical decisions (Hustad 8c Gearhart, 2004). Hustad and Gearhart (2004) investigated 168 listeners' attitudes towards 7 dysarthric speakers who implemented three different supplementation strategies (topic/subject cues, alphabet cues and combined topic-alphabet cues) by measuring ratings relating to cognitive, affective and behav ioural components of attitude. The results showed that rat ings for the behavioural component were the highest for all but one speaker. The study concluded that there is strong evidence of a positive relationship between intelligibility scores and attitude ratings, with attitude ratings increasing linearly with intelligibility scores.
In addition the study yielded important clinical impli cations for individuals who supplement their speech with AAC strategies. The implementation of combined cues or alphabet cues resulted in higher attitude ratings relative to topic cues and habitual speech. These strategies also resulted in the greatest intelligibility gains . As listeners appeared to be more willing to communicate with speakers who implemented alphabet or the combined cues strategies, the use of strategies aimed at enhancing intelli gibility will likely serve to particularly enhance the behav ioural attitude of listeners.
Also o f particular interest in recent studies is the means of defining the optimal listener-speaker pair. Familiarity has been among one of the many factors used in explaining variations in listener performance (DePaul 8c Kent, 2000).
Familiarity is however a vague and abstract concept, and for research purposes needs to be usable and measurable based on definable characteristics.' In a longitudinal case study, DePaul and Kent (2000) studied the effect of listener familiarity and proficiency on intelligibility judgements of individuals with MND. The results indicated better per formances for familiar listeners as opposed to unfamiliar lis teners. Familiar listeners were defined as individuals who had experience in communicating, on a daily basis with a person with a communication disorder. Unfamiliar listeners were defined as individuals that had no more than inciden tal experience listening to and communicating with persons having communication disorders. The results of this study suggest that speech-language pathologists should use listen er training as part of their practice standards in dysarthria treatment. The components should include: (i) establish ing pre-treatment listener's proficiency, (ii) training listen ers through familiarization techniques, and (iii) re-assessing intelligibility using these trained listeners.
Additional research examining familiarity with dysar thric speech is required in order to obtain conclusive results regarding the influence of familiarity on the speech intelli gibility of individuals with dysarthria.
This study is largely based on the previous work conduct ed by Hustad (2001b), which investigated 68 unfamiliar lis teners' evaluation of speech supplementation strategies used for severely dysarthric speech. As communication is dyad ic (Hustad 8c Beukelman, 2002), requiring interaction be tween the speaker and listener in communicative exchanges, speech intelligibility and listener attitude is a central con struct in the area of AAC (Hustad, 2001a,b). It is there fore o f significance to determine listeners' attitudes towards AAC and in particular speech supplementation strategies, as this can greatly influence the acceptance of AAC systems and strategies by the user.

Method Aim
The primary aim of the study was to compare unfamiliar and familiar listeners' attitudes towards the use of speech supplementation strategies (combined topic and alphabet cues) by speakers with mixed dysarthria. Three sub-aims delineate the means by which the primary aim of the study was realised: • To describe the effects of speech supplementation strate gies on listeners 'perception of communication effectiveness. • To describe the effects of speech supplementation strate gies on listeners' "willingness to interact with speakers. • To describe the effects of speech supplementation strat egies on listeners' ratings of persistence in trying to under stand speakers.

Research Hypotheses
As the research investigated the influence of two factors (familiarity and cues vs. no cues) on listener attitudes to wards speakers with dysarthric speech, two hypotheses were formulated. Firstly, familiar listeners will have significant ly higher ratings pertaining to their attitudes towards com municating with dysarthric speakers on the cognitive, af fective and behavioural components o f attitude. Secondly, it is hypothesized that the use of speech supplementation strategies will yield higher ratings on the cognitive, affec tive and behavioural components of attitude, than the use of no cues.

Research Design
A comparative research design was employed for the study (Schiavetti 8c Metz, 2006). This design was selected as it was appropriate to investigate the differences between the attitudes of the two groups of listener participants (fa miliar vs. unfamiliar) towards speakers with mixed dysar thria who use speech supplementation strategies.

Participants
The study involved the use of two participant groups. The speakers were individuals with M N D that presented with mixed dysarthria who produced speech samples. The second participant group included listeners that were either familiar or unfamiliar with communicating with a person with communication disorders.

Speakers with dysarthria
Three individuals with M N D that presented with mixed dysarthria participated in the study. Using a non-probabil ity, purposive sampling strategy (Schiavetti 8c Metz, 2006), speakers that met the following selection criteria were re cruited with the assistance from the Motor Neuron Disease Association (Gauteng): (i) diagnosis o f M N D made by a certified neurologist; (ii) used speech as their primary mode of communication; (iii) English first language speaker; (iv) reading ability at or above the 5th grade level; (v) presented with mixed dysarthria and in the 3rd or 4th stage of dysarthria  (Appendix A); (vi) speech intelligibility scores between 30 -70% as measured by the Sentence In telligibility Test (SIT) (Yorkston, Beukelman 8cTice, 1996), and;(vi) able to produce at least eight consecutive words in connected speech. See Table 1 for detailed information re garding each speaker.

Listener Participant Group
The primary participants in this study were the listen ers. A total of 36 participants were recruited for the study. A non-probability sampling strategy, 'purposive sampling' was employed to recruit the 18 familiar listeners (FL), and 'convenience sampling' to recruit the 18 unfamiliar listen ers (UL). The listener participant groups met the following criteria: (i) aged 30 -75 years; (ii) English first language speaker; (iii) no self-reported hearing loss; (iv) no identi fied language, learning, cognitive or visual disabilities per 'self report. Familiar listeners were defined as individuals (family member/friend/care worker) who had experience in communicating, on a daily basis with a person with a com munication disorder (Hustad, 2001a,b). Unfamiliar listen ers were defined as individuals that had no more than in cidental experience listening to and communicating with persons having communication disorders. The two listener groups were matched for gender and mean age. The unfa miliar listener group comprised of 18 participants (14 fe male, 4 male). Their average age was 58.0 years (range 32 to 75; SD=10.3). The familiar listener group recruited through the Parkinson's disease Association support group of South Africa, comprised of 18 listeners (14 female, 4 male). Their average age was 50.7 years (range 32 to 79; SD=14.8). De mographic information regarding listeners assigned to each listener group is provided in Table 2.
T able 2 . D em og rap h ic in fo r m a tio n fo r th e listen er g ro u p s

Materials Speech Stimuli
Four narrative passages, each consisting of 10 sentences were employed as speech stimuli. Narratives (Appendix B) representing situational information common to first lan guage English speakers were developed based on linguis tic characteristics specified in a study conducted by Hustad (2001b). The length and content of the stimulus material were equalised across the following linguistic parameters: (i) sentences per narrative; (ii) topic per narrative; (iii) words per narrative; (iv) number of words per sentence; and (v) reading level. Summary statistics for stimulus material are presented in Table 3. ,

__________ Characteristic___________ Number
Sentences per narrative 10 Topics per narrative 1 W ords per narrative 65 5-word sentences per narrative 2 6 word sentences per narrative 3 7 word sentences per narrative 3 8 word sentences per narrative 2 Reading level for each narrative 5

Questionnaire
A questionnaire (Appendix G) to measure the primary dependant variables was developed, and included demo graphic information and three statements probing listener DIE SUID-AFRIKAANSETYDSKRIF VIR KOMMUNIKASIE-AFWYKINGS, VOL. 5 5 ,2 0 0 8

Reproduced by Sabinet Gateway under licence granted by the Publisher (dated 2012.)
STRATEGIES FOR IMPROVING EFFECTIVENESS OF SPEAKERS WITH MIXED DYSARTHRIA attitudes in the cognitive, behavioural and affective domains. These statements were selected as they directly address the three components of attitude and were the same as those employed in the other studies (Hustad, 2001b;Hustad 8c Gearhart, 2004). Each of the three variables were measured using a 7-point ordinal Likert scale, with 1 = strongly disa gree and 7 = strongly agree. Listeners were required to circle the number which most closely represented their perception of each speaker. The statements were: (i) I think this person is an effective communicator using this strategy; (ii) I would feel comfortable communicating with this person in a class or at work if s/he used this strategy; and (iii) I would be will ing to communicate with this person in a class or at work if s/he used this strategy. In addition a qualitative question ("W hat feelings would you experience if you were to com municate with the speakers?") was included to obtain infor mation regarding the listener's feelings/emotions towards the speaker after hearing the speaker.

Data collection procedures Ethical considerations
Various ethical considerations were implemented throughout the research study. The researcher obtained ethi cal clearance from the Human Research Ethics Committee (medical) of the University of the Witwatersrand before this research study was implemented. Written informed consent was obtained from the M N D Association, Parkinson's dis ease Association and all participants, using established and approved methods. All participants in the study were fully informed of the nature of the study and were assured of an onymity and confidentiality. Each participant was required to sign a consent form, providing proof of his/her willing ness to partake in the study and had the right to withdraw from the study at any time, without suffering any negative consequences.
Data collection from the speakers with dysarthria: Re cording speech samples The recording of narrative samples took place in a qui et room in the speakers' homes, and were obtained using a Sony Mini-Disc Walkman (M Z-R900) digital audio re corder and a head mounted Sennheiser microphone to limit disturbance noises during the recording as a result of micro phone movement. jThe head mounted microphone helped to maintain a constant distance from the speaker's mouth so as to obtain correct! sound levels during the recording.
Each speaker was instructed to read all four narrative passages, printed in font size 20 and presented directly in front of the speaker, as naturally as possible to emulate a typical communication situation. The rate and prosody of the speakers was not controlled.

Constructing the stimuli (audio-visual footage)
The recorded speech samples were transferred digitally to a Toshiba Satellite (A100-519) laptop via the onboard sound card. The recordings were edited using digital audio editing software (Acoustica v4.0).The speech samples were edited to remove extraneous comments, and the amplitude of all the samples normalized to a -5 dB setting using the sound editing software to ensure that all the speech samples were at a similar volume level.
The edited speech samples were then combined with vis ual information to implement the combined topic-alphabet cue strategy using Windows Movie Maker software (version 6, Windows Vista OS). The visual orthographic information took the form of a text presentation on the screen showing the narrative topic cue, and the display of the first alphabet letter of each word spoken during the narrative. The display of the alphabet cue visuals was synchronized to the actual speech sample, so that as the speaker produced each word, the first letter was displayed simultaneously in real-time. For the stimuli where no cues were used, a blank screen was dis played in the background whilst the audio speech sample was played.
Presentation of stimuli to the listeners The final step involved the presentation of the compiled stimuli to the unfamiliar (UL) and familiar (FL) groups. The audio-visual recordings containing the narrative samples of the three speakers associated with the combined cue con dition and the no cues condition were presented to the 36 listeners.
All 36 listeners viewed the audio-visual footage in a quiet room at their place of residence. All the listeners were seat ed during the viewing with the laptop positioned directly (0.5m) in front of them. The volume was normalized at the maximum output o f the laptop for each listener, so that all the listeners listened to the stimuli at the same sound level.
Listeners were instructed that they would hear two speakers each reading a narrative, one purely auditory with out any supplementation cues and the other with the com bined alphabet and topic cue. The listener was briefed prior to the presentation on how the combined supplementation strategy worked and how it would appear on the screen.
Following the completion of the listening task, all partic ipants were requested to independently complete the ques tionnaires after receiving verbal and written instructions on the requirements of the questionnaire.

Randomization
To prevent the possibility of order and learning effect of cue conditions during the presenting of the narrative audio visual stimuli to the listeners, the sequence of the cue/no cue narratives shown to each listener was alternated. Different sequences and combinations of possible presentation orders for cues condition, speakers (3 speakers) and narratives (4 narratives) was used in the study. Each listener in the unfa miliar listener group was matched to one of the 18 in the fa miliar listener group. Therefore 18 sequences were displayed in total, ensuring that no two listeners were exposed to the same speaker, narrative, and cue combination.

Data Analysis
The values obtained from the Likert-type scales were re corded and collated for statistical analysis. Descriptive sta tistics were utilized to summarize and organize the data col lected. A two-way repeated measure Analysis of Variance (ANOVA) design was used (one-factor repetition) to de termine the effect of the two experimental ('familiarity' and 'cue/no cue') factors on the listeners' attitudes.
The design used a within-subjects repeated measure for the 'cues/no cues' factor in the design, since the listener at titude rating measurements for both the cues and no-cues condition were obtained from the same listener participants. Two different sample groups for the familiar and non-fa miliar listeners were used, and therefore repeated-measures THE SOUTH AFRICAN JOURNAL OF COMM UNICATION DISORDERS, VOL. 55 2008 | were not used for the 'familiarity' factor of the listeners in the research design.
The research design was employed for each of the three listener attitude components measured in the study. The three dependant variables were the listener ratings of com munication effectiveness (cognitive); listener feelings and emotions (affective); and willingness/persistence to com municate and understand the speaker (behavioural).

Results and Discussion
The results of the study will be described and discussed in this section in relation to the aims of the research. The results from the research data indicated mean listener at titude ratings across all listener and cue conditions ( UstenerGroups the combined cues and no cues condition. Listener emotions and feelings (affective) The mean attitude ratings for the affective attitude com ponent (see Figure 2) show similar results to those observed for communication effectiveness, with a slight difference observed in the ratings between the familiar listener (Com Listener willingness and persistence to communicate (behavioural) The results for the behavioural component (Figure 3) of the listener attitudes showed slightly higher mean ratings than the other attitude components. As observed in the pre- A two-way repeated measure Analysis o f Variance (ANOVA) test with one factor repetition for the 'cues/no cues'treatment was performed for each of the three depend ant measures. The test assumes that the treatment factors have equal variances (this assumption was confirmed for each set of dependent measure data by performing an equal variance test). The results of the test are described for each treatment factor ('Familiarity' and 'Cues condition) in the following section.
Listener Familiarity Hypothesis 1 stated that familiar listeners will have significantly higher ratings than unfamiliar listeners, per taining to their attitudes towards the speech o f dysarthric speakers, measured for the cognitive, affective and behav ioural components o f attitude. The results of this hypothesis, when tested using a two-way repeated measure ANOVA to compare the mean difference on the attitude ratings for FL as compared to UL is presented in Table 4.
Results o f testing hypothesis 1 The two-way repeated measure ANOVA tests applied to all 3 dependent measures (Table 4) indicates that the differ ences observed in mean values for the 'listener familiarity' factor is not sufficiently.large to exclude the possibility that the difference is due to random sampling variance, when the effects of the other factor (combined cues versus no cues strategy) is taken into account. Comparison of the F L and U L groups yielded mean differences between the groups of 0.444 for the cognitive component (P=0.730); 0.333 for the affective component (P=0.785); and 0.722 for the behav ioural component (P=0.592). Therefore there is no statisti cally significant difference in the scores of the F L sample group as compared to the U L sample group, across all 3 lis tener attitudes.
The study results therefore conclude that the hypothesis stating that 'familiarity' plays an influencing factor on the attitude ratings (all three components) of listeners is not valid. The effect of familiarization of the listener in influenc ing their attitudes towards dysarthric speakers would there in contrast to the results indi cated by the longitudinal study carried out by De Paul and Kent (2000), which concluded that a familiar listener had superior performance over unfamiliar lis teners. According to their study, the performance was significant ly improved especially during the individuals' second year of pro gression of M N D when their speech intelligibility decreased markedly.
Several factors may have con tributed to the current results. The familiar listener participant group was defined as listeners who had experience in commu nicating on a daily basis with persons with a communication disorder. However, it did not specify the degree of the dysar thria of the person that these fa miliar listener individuals com municated with or had contact with. In this study, the familiar listener participants were 'fa miliar' with individuals who had Parkinson's disease. It was noted that many o f the familiar listen ers communicated with individ uals in the early stages of Parkin son's disease, where their speech was only mildly impaired. These 'familiar' listener participants would therefore not have any substantial experience in com municating with speakers who had severe dysarthria.
In this study the duration of interaction between the famil iar listener and speaker was not specified and this variability of exposure was not taken into ac count. The familiar listener may have interacted with the in dividual for a month or a few years. This is in contrast to the longitudinal case study done by De Paul and Kent (2000). Therefore, the researchers' selection criteria had to be stricter in specifying the frequency and length of exposure to an in dividual with dysarthria, as well as the severity of dysarthria. However the researchers were unable to define the selection criteria to include exposure and stricter familiarity require ments for the study due to the nature and time limitations of the research.

Speech Supplementation Strategy (Combined cues vs. No cues)
Hypothesis 2: The use of a speech supplementation strategy, in this case the combined topic and alphabet cues will yield higher ratings, than the use of no cues pertain ing to listeners' attitudes towards the speech of dysarthric fore appear to play no significant role. This result is however THE SOUTH AFRICAN JOURNAL OF COMMUNICATION DISORDERS, VOL. 55 2008 speakers.

Results of testing hypothesis 2
The results of the two-way repeated measure ANOVA (one factor repetition) analysis are presented in Table 4 in the previous section. This analysis compared the mean dif ference on the listener attitude ratings for the use of the combined topic and alphabet cue, as compared to the use o f no cues pertaining to their attitudes towards the speech of dysarthric speakers. Three components of attitude were measured namely, cognitive, affective and behavioural.
C om m u n icativ e effectiv en ess (co g n itiv e); The two-way repeated measure ANOVA. determined that there was a statistically significant difference (P=<0.001) in the mean values among the different levels of cues. The difference in the mean values among the different levels of cues is greater than would be expected by chance after allowing for the ef fects of differences in familiarity.
The two-way repeated measure revealed ratings of effec tiveness that were significantly higher for combined cues than for the no cue condition. All the statistical findings for ratings of communication effectiveness in this study are consistent with intelligibility data obtained in previous studies (Hustad, 2003;Hustad &Beukelman, 2003;. The indication is that the combined topic and alphabet cue results in more favourable ratings of effective ness and intelligibility than the no cue condition. According to Hustad (2001b), a reason for the positive effect of the combined cue on effectiveness rating may be that all the listeners recognized attempts to enhance speech via the strategy presentation and they equated the use of the multiple supplementation strategies as trying "harder" to compensate to a greater extent for the communication difficulties.
L is te n e r co m fo rt a n d em otion (a ffe c tiv e ): Similarly, the two-way repeated measure ANOVA determined that there was a statistically significant difference (P=< 0.001) in the mean values among the different levels of cues. As was the case for listener effectiveness combined cues yielded more favourable affective attitude ratings than the no cue con ditions. The results suggest that the more information the listener has about a topic the more comfortable they would be to interact with the speakers. Participants stated that be cause they were provided with the topic of the narrative, as well as the alphabet cues, they were able to anticipate and understand more o f what the speaker was saying.
L is te n e r p ersisten c e (b eh a v io u ra l): Again, the two-way repeated measure ANOVA determined that there was a sta tistically significant difference (P= <0.001) in the mean be havioural rating. Listeners are therefore more persistent to interact with speakers that employed the combined topic and alphabet cue supplementation strategy in conjunction with their habitual speech, as compared to the no cue con dition.
The overall results o f the present study showed that the UL and FL sample groups were from the same population group and therefore listener familiarity was not a favourable indicator of increased intelligibility and listener attitude rat ings. However, the present study did show that the com bined alphabet and combined cue supplementation strategy used in conjunction with habitual speech, resulted in sig nificantly higher ratings o f listeners'perceptions of the com munication of speakers with dysarthria ranging from 33% -67% intelligibility.
It is however important to consider these findings in light o f the limitations of the research. The study employed a traditional experimental paradigm which differs significant ly from naturalistic, real life communication situations. As the speakers and listeners did not converse and interact with one another in communicative exchanges, extra-linguistic factors such as gesture, body language and facial expression used in conjunction with verbal communication were omit ted. The listeners were also not able to directly interject and ask for clarification from the speaker.
The content, form and use of messages produced by the speaker were also scripted, and the environment in which the listeners heard the audio recordings was manipulated for an ideal listening and viewing condition. The audio-visual material presented to the listeners for viewing and listen ing was digitally enhanced, so that all the cues used were clearly and readily visible. In a real life situation and im plementation of these supplementation strategies, the com municative partner does not have the advantage of this type of digital enhancement. The communicative partner would have to deal with the effects of lighting, distance from the speaker and the angle at which the partner is facing towards the speaker. In addition the speech patterns of the speaker may have been different if they were directly implementing the supplementation strategy, for example slowing down of their speech rate as they point to the various alphabet cues, thus affecting their overall speech intelligibility as perceived by the listener. These factors need to be considered in light of the current research.
The sample size of the study involved only 3 speakers with dysarthria and 36 listener participants; therefore this relatively small sample size may have an influence on the reliability and validity of the study. In addition the partici pants in the study were restricted to a specified age range. The results indicated by the study may not be fully repre sentative of the general population. ' In this study, only three Likert-type questions were used to gather information regarding listener attitudes. Although the construct of attitude and its constituent components (cognitive, affective and behavioural) are well grounded in literature (Hustad 8c Gearhart, 2004), measurement of these constituents in a research study is more complex. The measurement of listener attitudes based on three questions cannot fully account for the many different facets of a listen er's attitude and it is suggested that future research should aim to adapt or develop a more comprehensive instrument with well-described psychometric properties to explore lis tener attitudes.
The results of the qualitative question: "W hat feelings would you experience if you were to communicate with the ■ ■ speakers?"indicated a few general trends across all 36 listen ers'emotional reactions towards the 3 speakers. The majority of listeners felt a great sense of empathy and awkwardness towards the speakers because they acknowledge the speak ers' intent to communicate, but still struggled to understand them. Listeners stated a great sense of awkwardness in not knowing what the speaker is saying and not being able to re 70 | DIE SUID-AFRIKAANSETYDSKRIF VIR KOMMUNIKASIE-AFWYKINGS, VOL. 55, 2008 Reproduced by Sabinet Gateway under licence granted by the Publisher (dated 2012.) spond appropriately during a communicative exchange.
Listeners also stated becoming highly frustrated with the speakers and frequently becoming quite impatient. Most of the participants stated that it would have been easier to un derstand what the speaker was saying, if they were face-toface with the speaker in comparison to only being able to listen to a recording of their speech.
The majority of the participants did indicate that they found the cues beneficial in helping them to understand the speaker. However, a few listener participants did state that they found the visual cues misleading, stating they had difficulty in focusing on the cues and integrating the visual and auditory stimuli (this was particularly evident when the speaker spoke at a fast rate).

Conclusion
The overall aim of the study was to determine the influ ence of familiarity on a listener's attitude towards speakers with mixed dysarthria. The findings of this study concluded that familiarity has no statistically significant influence on their attitudes towards speakers with mixed dysarthria.
The results, however did suggest that speakers whose speech intelligibility is severely reduced may benefit mark edly from using a combined topic-alphabet cue strategy, as within this experimental research paradigm, the combined cue strategy resulted in more favourable listener attitudes. In addition, listeners appeared to be more comfortable and persistent in communicating with speakers who implement ed the combined cues. Although many variables are likely to influence listener attitudes, there is strong evidence to sug gest that listener attitudes are closely linked to intelligibility (Hustad 8c Gearhart, 2004).
The findings of the influence of familiarity on the listener attitudes may possibly have been affected by the time con straints imposed on the study and an insufficient definition o f the familiar listener. It is suggested that the definition of a familiar listener include specific detail on the duration and frequency of interaction with the person with dysarthria as well as the severity o f the reduction in the speaker's intelli gibility. Other studies (DePaul 8c Kent, 2000) indicated that familiarity does lead to significant performances on speech intelligibility and therefore listener attitudes. It further in dicated that an advantage of familiarity evolved over time and reached a maximum level when the speech impairment was significantly reduced in intelligibility (DePaul 8c Kent, 2000).
The results of the study should be interpreted in light of the experimental nature o f the study where the listeners did not communicate in a real communicative exchange and it therefore does not permit generalisation to ecologically val id communication situations.
This study however has important implications in the clinical management of individuals with motor speech dis orders, such as dysarthria. The implementation of speech supplementation strategies such as the use of combined alphabet-topic cues can improve the communicative effective ness and lead to more favourable interactions with listeners.
Future research should address the attitudes of unfamil iar and familiar listeners towards individuals with different severity levels and speech characteristics, using more natu ralistic speech samples. It is important that future research should take intra-rater reliability into account by repeating a small proportion of speech samples. In addition, a quali tative approach could be employed to investigate how AAC strategies affect listener attitudes to provide information re garding what listeners think, feel and believe when faced with speakers using AAC.

APPENDIX B
NATALIE TOY AN D KARIN JOUBERT Narrative Stimuli

Narrative 1: A holiday
It was an amazing holiday (5). We gathered shells on the beach (6). We also saw dolphins swimming in the sea (8). We spent hours lying in the warm sun (8). One day we hiked up Table Mountain (7). The view was so magnificent and peaceful (7).lt was the best experience ever (6). We have a beautiful country (5).The week had come to an end (7). My fun holiday had officially ended (6).

Narrative 2: A sporting event
The two Batsmen walked onto the cricket field (8). The crowd was cheering wildly (5).
Everyone was standing and clapping their hands (7). The sun was shining directly overhead (6). The Umpires briefly spoke to each other (7). They asked the players to begin the match (8). Each player went to their position (6). The crowd started a Mexican wave (6). It went round and round the stadium (7). It was a great game (5).

Narrative 3: My wedding day
The special day had arrived (5). Finally, my eldest daughter was leaving home (7). It was an exciting day (5). The church hall was decorated with red roses (8). The bridesmaids wore pink satin dresses 6). The groom and his best man wore white tuxedo's (8). A silver limo arrived at twelve o' clock (7). The wedding music started to play (6). We walked together down the aisle(6). Then my daughter looked at me and smiled (7).

Narrative 4: The Trip To The Doctor
I woke up with a fever and headache (8). I could barely sit up (5). I was in such pain and discomfort (7). The whole night I could not sleep (7). My grandmother took me to the doctor's office (8). I waited there for 40 minutes (6). My grandmother was angry and frustrated (6).
Finally, I went into the doctor's office (7). I hated going to the doctor (6). I went home and slept (5).