Selection of Voice Therapy Methods. Results of an Online Survey

Selection of Voice Therapy Methods. Results of an Online Survey Iris Burg, Birte Meier, Katharina Nolte, Tina Oppermann, Verena Rogg, and Ulla Beushausen, Hildesheim, Germany Summary: Objectives. Providing an evidence basis for voice therapy in the German-speaking countries faces the challenge that—for historical reasons—a variety of direct voice therapy methods is available. The aim of this study was to clarify which therapy methods are chosen and the underlying principles for this selection. Methods. An online survey was implemented to identify to what extent the variety of methods described in theory is also applied in practice. A total of 434 voice therapists in Germany, Austria, and Switzerland were asked, among other things, which methods they prefer. Results. A significant majority of therapists do not apply one specific method but rather work with a unique combination of direct voice therapy methods for individual clients. These results show that the variety of methods described in the literature is also applied in voice therapy practice. The combination of methods becomes apparent during the choice of exercises. The type of voice disorder plays no decisive role in the method selection process, whereas certain patient variables do have an influence on this process. In particular, the patients’ movement restrictions, their state of mind or mood on a given day, and aspects of learning theory are taken into account. Conclusions. The results suggest that a patient-oriented selection of appropriate exercises is of primary importance to voice therapists and that they rarely focus on specific direct voice therapy methods. It becomes clear that an evaluation of single methods does not correspond to practical experience, and therefore, an overall evaluation of voice therapy appears to be more useful. Key Words: Voice therapy–Methods–Selection of methods–Effectiveness–Patient variables. INTRODUCTION Since the end of the 19th century, different concepts have been developed to treat voice disorders. In the German-speaking countries (Germany, Switzerland, and Austria), experts from the fields of medicine, vocal pedagogy, speech science, language special education, and speech therapy have established at least 20 different concepts. These methods can be classified according to their theoretical foundation, independence of method, and the extent of the combination of psychotherapeutic and speech therapeutic principles.1 On the one hand, this variety of methods enriches the therapy; on the other hand, evidence for voice therapy becomes more difficult to obtain, as every method needs to be investigated with regard to its effectiveness and efficiency.2

Research question A method-independent evaluation of the effectiveness and efficiency of voice therapy does not yet exist for either the Anglo American or the German-speaking areas. Considering the theoretical variety of methods, it has hardly been investigated how voice therapy is implemented in the German-speaking countries. There is no evidence that the variety of methods described in the literature is reflected in practice. This has to be answered before a method-independent evaluation of voice therapy can be done. Furthermore, the principles for choosing the methods used in voice therapy should be identified. Accepted for publication December 30, 2014. From the Faculty of Social Work and Health, HAWK University of Applied Sciences and Arts, Hildesheim/Holzminden/G€ottingen, Hildesheim, Germany. Address correspondence and reprint requests to Ulla Beushausen, Faculty of Social Work and Health, HAWK University of Applied Sciences and Arts, Hildesheim/ Holzminden/G€ ottingen, Goschentor 1, D-31134 Hildesheim, Germany. E-mail: [email protected] Journal of Voice, Vol. -, No. -, pp. 1-6 0892-1997/$36.00 Ó 2015 Published by Elsevier Inc. on behalf of The Voice Foundation http://dx.doi.org/10.1016/j.jvoice.2014.12.011

Aim of the study The aim of the questionnaire was to collect data on the structure of voice therapy and the factors affecting the selection of methods and exercises. Principles influencing the selection of methods and exercises were to be identified. The results of an interview data collection by Beushausen1 with 12 experts in the field of voice therapy were to be refuted or supported. The expert interviews suggested that speech and language therapists (SLTs) always use a combination of methods. They indicated that the number of combined methods increases depending on professional experience. A focus on only one method could not be proved.1 Theoretical positioning and hypotheses. In Englishspeaking countries, some meta-analysis and systematic reviews do exist. They point out the effectiveness of direct and indirect voice therapy methods as results from randomized controlled studies.3–6 In German-speaking countries, the effectiveness of specific methods has been researched through pre-post designs, for example, the nasalization method of Pahn and Pahn7 and the effects of electrostimulation therapy on vocal fold paresis.7–9 Routsalainen et al pointed out a high treatment efficiency by combining direct and indirect therapy methods.10 In 2013, two studies from the Anglo American area documented that therapists always combine different methods and that this combination happens independently of the type of voice disorder.11,12 However, these results are only conditionally transferable because the repertoire of existing voice methods is diverse in English- and German-speaking areas. Only the accent method is internationally prevalent.7,13–15 Overall, there is only minor evidence of voice therapy intervention.6 In a qualitative study with 12 voice therapy experts, interviews were conducted to collect information about voice therapy in the German-speaking countries, its concrete form, and the basic principles.1 On the basis of these results and the subsequent

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TABLE 1. Description of the Sample Occupational group Qualification (n ¼ 434)

Country (n ¼ 434)

Age (n ¼ 430) Professional experience (n ¼ 432) Sex (n ¼ 434)

Number of voice therapy session a therapist offers generally per week (n ¼ 433) Place of employment (multiple choices possible)

Speech and language therapists Professional training Diploma Bachelor Master Magister Other n/a Germany Austria Switzerland Other n/a 21–81 y (mean, 38.37; SD, 10.93) 1–50 y (mean, 11.99; SD, 9.32) Female Male n/a 1–50 Therapies/wk (mean, 11.99; SD, 9.32)

434 (100%) 252 (58%) 70 (16%) 70 (16%) 16 (4%) 11 (3%) 9 (2%) 6 (1%) 349 (80%) 66 (15%) 12 (3%) 4 (1%) 3 (1%)

Private practice Hospital Professional college University Other

362 (83%) 62 (14%) 42 (10%) 22 (5%) 45 (10%)

396 (91%) 31 (7%) 7 (2%)

Abbreviations: SD, standard deviation; n/a, not applicable.

literature, the following hypotheses were generated as the basis for developing a questionnaire. Hypothesis 1: In voice therapy, therapists combine different methods for one patient. Hypothesis 2: The quantity of applied methods rises with increasing professional experience. Hypothesis 3: In their selection of methods, therapists consider patient variables such as age, learning type, actual constitution, motivation, musical aptitude, sex, and level of education. Hypothesis 4: The selection of applied methods is dependent on the type of voice disorder. METHODS A questionnaire was developed in an expert group of five therapists and pretested to five practitioners during a standardized interview after completion of the questionnaire.16 To maintain objectivity, the analysis was conducted by two independent assessors, and the results were discussed in a different expert group. The final version of the questionnaire was completed by voice therapists in Germany, Austria, and Switzerland in an anonymous online questionnaire survey (Limesurvey Version 1.71, GPL-Lizenz by limesurvey). The target groups were members of all occupational categories who were actively working in voice therapy at the time of data collection (Table 1). The sampling procedure was carried out via the link to our home page: www.stimmumfrage.de. This link was distributed in different ways, for example, by the professional associations of SLTs in Germany, Austria, and Switzerland and through an

article in a professional journal in Germany. Moreover, we used the social network Facebook. The total number of questionnaires received amounted to 724. Data sets of Germanspeaking therapists with a completed professional training as an SLT and at least one voice therapy per week were included. Furthermore, the questionnaires had to be filled in completely. After applying these criteria, 290 records had to be excluded and 434 data sets were included. The main aspects that were surveyed through the questionnaire included basic parameters (frame conditions) in voice therapy, methodologic knowledge and method choice, relevance of psychogenic factors within therapy, diagnostic findings, evaluation of success through therapy, interdisciplinary cooperation, method choice in relation to specific clinical portraits of voice disorders (functional, organic, or psychogenic dysphonia; paresis), and patient variables (age, sex, level of education, learning type, and so forth).12 Regarding the different kinds of voice disorders, a distinction was made between vocal fold paresis, organic dysphonia (all other organic voice disorders except vocal fold paresis), functional dysphonia (hypofunctional and hyperfunctional dysphonia), and psychogenic dysphonia (aphonia or dysphonia due to psychosomatic or psychosocial influences). In questions concerning the knowledge and selection of particular methods, 19 methods of voice therapy (based on the literature) were provided for choice (for a brief description of the classification and the principles of methods in the German-speaking countries, see Table 2).

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TABLE 2. Brief Description of the Most Frequently Used Voice Therapy Methods in the German-Speaking Countries Classification

Year of Publication

Principle/Description

First method in Germany

Concept of SchlaffhorstAndersen

1928

Classical methods

Chewing method

1952

Respiratory litter

1955

Method of nasalization

1969

First method for treating voice disorders; holistic; respiration provides the basis for physical and mental health. Uses chewing exercises for widening the throat and making the larynx elastic; based on changes in articulation. Based on breath function and articulation. Based on articulation and inactivation of the velum during phonation. Based on the coordination of movement, articulation, phonation, and breathing. Uses the relaxation of the diaphragm for improving phonation; adjusted according to the dialog partner. The principal component is the rhythm of phonation and movement; indirect method based on the role model of the therapist. Physical and mental processes of the client are involved in the therapy. Therapy is based on pedagogy of singing and is function oriented. It tries to activate the lowpressure system of the larynx. The voice disorder is seen as an expression of the whole personality of the client; the aim is to create a responsible client. Mobilization of the organic structures that are involved in phonation. Supports externally the contraction of the musculus vocalis with electric stimulation.

Continuative methods

Recent methods

Others

Concept/Method

Respiratory adapted phonation

After 1970

Accent method

After 1970

Personal voice therapy

1996

Functional voice therapy

1980

Integrative voice therapy

2000

Manual voice therapy

2003

Electrostimulation therapy

The naming of further methods was possible as well (Table 3).17,18 According to the type of question, the possibilities for answering differed from dichotomous to a four-point Likert scale. Data analysis was carried out with SPSS version 19 (by IBM Statistics, Ehingen, Germany).

Since 1960

RESULTS The presentation of the results is subdivided into knowledge, application, and selection of direct voice therapy methods. The influence of patient variables and the type of voice disorder on selection and the differences in specifically defined subgroups are presented as well.

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TABLE 3. Currently Applied Methods (n ¼ 434) Process-oriented voice therapy Scenic emotion-centered voice therapy Psychodynamic therapy approach Transactional analysis Interactional and integrative voice therapy Direct voice therapy Method of nasalization Electrostimulation therapy Personal voice therapy Manual voice therapy Integrative voice therapy Respiratory litter (‘‘Atemwurf’’) Concept of Schlaffhorst-Andersen Accent method Chewing method Respiratory adapted phonation Functional voice therapy

5.3% 5.8% 7.8% 9.7% 10.4% 10.4% 26.5% 26.5% 36.9% 41.5% 44.2% 55.5% 56.2% 62.7% 83.6% 87.1% 91.0%

Knowledge and application of methods During their professional practical training, 78.1% (n ¼ 339) of the interviewed therapists learned the respiratory adapted phonation by Coblenzer and Muhar; 71.0% (n ¼ 308) the chewing method by Froeschels; 49.5% (n ¼ 215) of the respondents learned one form of the functional voice therapy approaches; 47.7% (n ¼ 207) the respiratory litter, or the so-called Atemwurf, by Fernau-Horn; 43.8% (n ¼ 190) the accent method by Smith and Thyme-Frøkjær; and 38.0% (n ¼ 165) the concept of Schlaffhorst-Andersen. Of the 44 respondents, 10.1% stated that they learned only one method during their professional training. Of the 383 interviewed persons, 88.2% reported that they learned between 2 and 11 different methods. On average, 4.3 (standard deviation [SD], 2.185; n ¼ 434) methods were practically learned. With regard to theoretical education, 86.2% (n ¼ 374) of the respondents learned the chewing method, 84.6% (n ¼ 367) the respiratory adapted phonation, 70.7% (n ¼ 301) the accent method, 64.5% (n ¼ 280) the respiratory litter, 63.1% (n ¼ 274) one form of functional voice therapy approaches, and 61.1% (n ¼ 265) the concept of Schlaffhorst-Andersen.

Selection of methods in voice therapy The results indicate that the respiratory adapted phonation, the chewing method, and different functional voice therapy approaches are currently the most commonly applied methods in voice therapy in German-speaking countries (Table 3). Only 9% of the respondents never use one of the functional voice therapy approaches. On average, the interviewed therapists use 7.3 (SD for standard deviation, 2.914; n ¼ 434) different methods. To answer the question of how methods are selected for a single patient, participants were asked among other things, (1) if varying exercises of different methods are combined for one patient, (2) if one appropriate method is selected from several methods for one patient, or (3) if one method is generally preferred (Table 4). A significant majority of respondents stated that they always combine exercises from different methods in one patient’s therapy (62.9%, n ¼ 273, chi-square ¼ 447.943, r ¼ 16.395, P < 0.001). When asked if they select one appropriate method for one patient, most of the interviewed persons (35.5%, n ¼ 154) answered that they do so rarely. The general preference of one method was rejected by 44.2% (n ¼ 192) of the respondents. Hypothesis 1 was thus confirmed. Selection factors for voice therapy methods The theoretical and practical knowledge acquired during professional training is reflected in the methods used by the therapists at the beginning of their professional life. Of the 313 entrants, 72.1% apply the respiratory adapted phonation, 61.5% (n ¼ 267) use the chewing method, 48.8% (n ¼ 212) one form of functional voice therapy approaches, 35.7% (n ¼ 155) the respiratory litter, 35.3% (n ¼ 153) the accent method, and 29.7% (n ¼ 129) of the entrants work according to the concept of Schlaffhorst-Andersen. A closer look at the applied methods in relation to the professional experience of the interviewed therapists reveals that respondents with <10 years of work experience use on average 6.5 (SD, 2.688; n ¼ 215) different methods, whereas respondents with more than 10 years of work experience use on average 8.1 (SD, 2.850; n ¼ 202) different methods. The number of applied methods correlates significantly (r ¼ 0.327, P < 0.01) with the professional experience of the therapists.

TABLE 4. Selection of Methods Selection of Method I combine exercises from different methods in the voice therapy with one patient. I choose one suitable method of several methods for one patient. I generally prefer a specific method. Abbreviation: n/a, not applicable.

Always, % (n)

Frequently, % (n)

Rarely, % (n)

Never, % (n)

n/a, % (n)

62.9 (273)

29.5 (128)

3.2 (14)

1.2 (5)

3.2 (14)

7.1 (31)

12.4 (54)

35.5 (154)

28.6 (124)

16.4 (71)

8.8 (38)

10.6 (46)

17.5 (76)

44.2 (192)

18.9 (82)

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TABLE 5. Answers to the Question: Which Patient Variables Influence Your Selection of Methods? Patient Variable Movement restriction Patient’s state of mind or mood Patient motivation Perceptual type (rational/ emotional) Learning type (visual/ auditory/kinesthetic) Age Musical background Sex Level of education

Always, % (n)

Frequently, % (n)

Rarely, % (n)

Never, % (n)

n/a, % (n)

44.5 (193) 31.3 (136)

37.6 (163) 40.3 (175)

10.1 (44) 16.6 (72)

3.9 (17) 6.7 (29)

3.9 (17) 5.1 (22)

27.4 (119) 21.9 (95)

40.8 (177) 44.5 (193)

19.1 (83) 19.6 (85)

8.8 (38) 8.5 (37)

3.9 (17) 5.5 (24)

17.3 (75)

32.3 (140)

30.0 (130)

13.1 (57)

7.4 (32)

16.1 (70) 12.7 (55) 7.1 (31) 5.5 (24)

29.7 (129) 32.0 (139) 18.7 (81) 15.4 (67)

35.5 (154) 33.6 (146) 41.9 (182) 45.9 (199)

13.1 (57) 16.8 (73) 26.7 (116) 28.1 (122)

5.5 (24) 4.8 (21) 5.5 (24) 5.1 (22)

Abbreviation: n/a, not applicable. Notes: Highest score for each category is in bold.

Because the therapeutic repertoire expanded with increasing professional experience, hypothesis 2 was thus also confirmed. Furthermore, because the patient variables formulated by Roy and Bless19 were also examined, these may influence the selection of methods and exercises of the therapists (hypothesis 3). With regard to the selection of methods, most therapists stated that the restriction of a patient’s movement always influences the choice of methods (Table 5). Also, often considered are the patient’s state of mind or mood, motivation, perception type (rational/emotional), and learning type (visual/auditory/ kinesthetic). The choice of methods is less influenced by the age or the musical aptitude of a patient and rarely by gender and the level of education. Hypothesis 4 predicted that the choice of voice therapy methods is based on the underlying type of voice disorder. This could not be confirmed. Judging from the order of the most frequently used methods, no differences (except for the

use of electrostimulation therapy) are discernible among functional voice disorders, paresis, and organic dysphonia. The choice of methods thus seems to occur independently of the type of voice disorder. As expected, electrostimulation therapy is used primarily in paresis (23.7%, n ¼ 103) and less with organic or functional voice disorders. In the case of psychogenic voice disorders, in contrast, the personal voice therapy of Stengel and Strauch is increasingly used. The accent method and the respiratory litter rarely find application with this type of voice disorder (Figure 1). Differences between the professional groups and compared countries. In the following, the SLTs from Germany (n ¼ 340) and Austria (n ¼ 66) will be compared with each other. In Austria, the most commonly conducted and learned methods of SLTs are the respiratory adapted phonation, chewing method, and functional voice therapy approaches. However, in comparison with German SLTs, the integrative

FIGURE 1. Selection of methods with different types of voice disorder.

6 voice therapy by Haupt is more often taught and applied in Austria, whereas the accent method and the nasalization method are rarely used by the Austrian SLTs. DISCUSSION The results of this survey show that most of the therapists in Germany and Austria implement a variety of methods in voice therapy. Because of the small sample size, no valid conclusions can be drawn for Switzerland. Most therapists learn a variety of methods during their professional training. With increasing professional experience, more methods are added to the therapeutic repertoire. Most subjects therefore do not seem to decide on one single method but instead constantly expand their range or spectrum of applied methods. The diversity of methods described in the literature11,12 seems to be reflected in the practice of voice therapy. The six most frequently used methods are also among the oldest methods used in voice therapy, having been developed between 1890 and 1980. Most therapists often specify a combination of exercises of different methods. Only a few therapists generally prefer one method. These results coincide with the results of the study by Chan et al,11 in which 58 Australian therapists were asked about their method selection in voice therapy. The type of voice disorder apparently plays no decisive role in the selection of a method. This is consistent with recent studies in Australia and the United States.11,12 The choice of methods is thus not primarily influenced by the type of voice disorders of the patient but rather by patient variables. These include psychological, motivational, and learning theory characteristics. To what extent other variables such as therapist variables have an influence should be investigated in future. The results of the survey show that most voice therapists choose patient-specific vocal exercises from a subordinate level of methods and combine them. Very rarely do they seem to choose only one method for one patient. It thus appears more likely that they place more importance on the selection of a suitable exercise for a patient than on the orientation toward specific methods. CONCLUSIONS The results show that in future studies, comprehensive principles of voice therapy can be evaluated for the effectiveness and efficiency of voice therapy. Individual proofs of the effectiveness of about 20 existing direct voice therapy methods are not sufficient because the use of only one method is virtually nonexistent in therapeutic practice. The results of this questionnaire survey support the findings of the qualitative study of Beushausen1 and are consistent with recent results from Anglo American scholarship. Future studies should determine the effectiveness of individual exercises or exercise combinations (the type, extent, and timing) in voice therapy. In addition, further research is needed to examine which aspects influence

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the selection of exercises above and beyond the patient variables. Acknowledgments The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article. REFERENCES 1. Beushausen U. Methodenorientierung in der Stimmtherapie. Stimmtherapeutische Methoden und ihr Einsatz in der therapeutischen Praxis – eine qualitative Studie. Forum Logop€adie. 2012;26:30–35. 2. Beushausen U, Burg I, Oppermann T, Nolte K, Meier B, Rogg V. Evidenzbasierte Stimmtherapie? Ergebnisse einer repr€asentativen Therapeutenbefragung zu den Inhalten, Methoden und Zielsetzungen in der Stimmtherapie. In: Gross M, Sch€onweiler R, eds. Aktuelle phoniatrischp€adaudiologische Aspekte, Bd. 21. Ort: Verlag; 2013:197–200. 3. Carding PN, Horsley IA, Docherty GJ. A study of the effectiveness of voice therapy in the treatment of 45 patients with nonorganic dysphonia. J Voice. 1999;13:72–104. 4. Holmberg EB, Hillman R, Hammarberg B, S€odersten M, Doyle P. Efficacy of a behaviorally based voice therapy protocol for vocal nodules. J Voice. 2001;15:395–412. 5. Morsomme D, Faurichon de la Bardonnie M, Verduyck I, Jamart J, Remacle M. Subjective evaluation of the long-term efficacy of speech therapy on dysfunctional dysphonia. J Voice. 2010;24:178–182. 6. Ruotsalainen JH, Sellman J, Lehto L, Jauhainen M, Verbeek JH. Interventions for treating functional dysphonia in adults. Cochrane Libr. 2009;1: 1–29. 7. Sch€onweiler R, Mergardt D, Raap M. Pilotstudie zur Effektivit€at der Stimm€ubungstherapie mit NMEPS-Reizstrom und der Nasalierungsmethode. Logos Interdisziplin€ar. 2005;13:36–42. 8. Ptok M, Strack D. Klassische Stimmtherapie versus Elektrostimulationstherapie bei einseitiger Rekurrensparese. HNO. 2005;53:1092–1097. 9. Ptok M, Strack D. Therapeutische Beeinflussung von Schwingungsirregularit€aten durch Elektrostimulationstherapie. HNO. 2009;57:1157–1162. 10. Eicher I, van Thiel I. Therapiebausteine in der Stimmtherapie. Beschreibung und Evaluation. Versuch eines Beitrags zur Standardentwicklung in der Stimmtherapie. Logos Interdisziplin€ar. 2010;18:110–117. 11. Chan AK, McCabe P, Madill CJ. The implementation of evidence-based practice in the management of adults with functional voice disorders: a national survey of speech-language pathologists. Int J Speech-Lang Pathol. 2013;15:334–344. 12. Gartner-Schmidt JL, Roth DF, Zullo TG, Rosen CA. Quantifying component parts of indirect and direct voice therapy related to different voice disorders. J Voice. 2013;27:210–216. 13. Bassiouny S. Efficacy of the accent method of voice therapy. Folia Phoniatr Logop. 1998;50:146–164. 14. Fex B, Fex S, Shiromoto O, Hirano M. Acoustic analysis of functional dysphonia: before and after voice therapy (accent method). J Voice. 1994;8:163–167. 15. Kotby MN, El-Sady SR, Basiouny SE, Abou-Rass YA, Hegazi MA. Efficacy of the accent method of voice therapy. J Voice. 1991;5:316–320. 16. Pr€ufer P, Rexroth M. In: Kognitive Interviews. ZUMA How-to-Reihe, Nr. 15. Mannheim: Zentrum f€ur Umfragen, Methoden und Analysen; 2005. 17. Hammer S. Stimmtherapie mit Erwachsenen. Was Stimmtherapeuten wissen sollten. 5th ed. Heidelberg: Springer; 2012. 18. Kruse E. Conservative approaches to the management of voice disorders. GMS Curr Top Otorhinolaryngol Head Neck Surg. 2005;13:1–18. 19. Roy N, Bless DM. Personality traits and psychological factors in voice pathology: a foundation for future research. J Speech, Lang Hear Res. 2000; 43:737–748.