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Analysis and Evaluation of a Voice-Training Program in Future Professional Voice Users
Analysis and Evaluation of a Voice-Training Program in Future Professional Voice Users *†Bernadette Timmermans, †Marc S. De Bodt, †Floris L. Wuyts, and †Paul H. Van de Heyning Brussels and Edegem, Belgium
Summary: The goal of this study is to analyze and evaluate the effectiveness of a voice-training program. Twenty-three professional voice users received voice training for 2 years and vocal hygiene education for 1 year. The voicetraining program consisted of lectures, technical workshops, and vocal coaching. The European Laryngological Society (ELS) protocol, including the Dysphonia Severity Index (DSI) and the Voice Handicap Index (VHI), was applied before and after, respectively, 9 and 18 months of voice training. A questionnaire on daily habits was presented at study onset and after 18 months. The DSI improvement is more significant after 9 months (P ⫽ 0.005) than it is after 18 months (P ⫽ 0.2). On the other hand, the perceptual evaluation remained unchanged after 9 months, whereas it improved significantly after 18 months. The results of the daily habit questionnaire are disturbing: the prevalence of smoking, vocal abuse, stress, and late meals were not influenced by the lectures and remained high. This study emphasizes the need for a well-organized voice-training program that is most effective after 9 months. Regarding the low effectiveness of the vocal hygiene program, the concept needs revision. Key Words: Voice quality—Vocal hygiene—Outcome—Professional voice users—Voice-training program.
INTRODUCTION
Accepted for publication April 26, 2004. From the *Department Rits, Erasmus Institute, Brussels, Belgium; †Faculty of Medicine, Department of Otolaryngology, Head and Neck Surgery and Communication Disorders, University Hospital Antwerp, UA, Belgium. Address correspondence and reprint requests to Bernadette Timmermans, Department of Otolaryngology, Head and Neck Surgery and Communication Disorders, University Hospital Antwerp, UA, Wilrijkstraat, 10, B-2650 Edegem, Belgium. E-mail: [email protected] Journal of Voice, Vol. 19, No. 2, pp. 202–210 0892-1997/$30.00 쑕 2005 The Voice Foundation doi:10.1016/j.jvoice.2004.04.009
This study concentrates on the effectiveness of a voice-training program for 23 future professional voice users, such as actors and radio directors. As this population needs a well-functioning voice, but also a resonant and beautiful voice, everybody expects that this category of professional voice users receives voice training. Nevertheless, scientific research on the training effect is rare.1 In a previous study, Timmermans et al1 assessed 86 voices of future professional voice users by means of the European Laryngological Society protocol 202
PROFESSIONAL VOICE USER TRAINING (ELS)2 and concluded that the vocal characteristics and the self-perception of future professional voice users are not as good as expected. However, after 9 and 18 months of voice training, 46 voices were assessed again and a significantly improved objectively measured voice quality (Dysphonia Severity Index, DSI)3 and a significant betterment of the perceptual evaluation (GRBAS scale, where G stands for grade of overall hoarseness, R for roughness, B for breathiness, A for asthenity, and S for strain)4 were found. The self-assessment (Voice Handicap Index, VHI),5 however, showed that the actor and radio students experience their voices as problematic. In spite of this, they neglect the rules of vocal hygiene as a lot of them smoke, many report stress, abuse the voice, and eat very late because of scholar obligations.6,7 In this study, a comparative analysis of the results of the three assessment moments—at study onset (Time 1), after 9 months (Time 2), and after 18 months (Time 3), was performed to determine the impact of each training phase. Comparing the results over time can reveal important and useful information about the effectiveness of the training program, the optimal period of training, and the effect of vocal hygiene. This information can be helpful in the construction and optimization of a future training program for this population. MATERIALS AND METHODS Subjects Subjects are between 19 and 30 years old and students of the Rits,1 ie, school for audiovisual communication. The 23 subjects (13 males and 10 females) received 18 months of voice training, which is a basic element in their study program. This group, further called the trained group, consists of future actors or radio directors (radio directors create, direct, and present their own radio programs; presentation is desirable but is allowed only with a good voice and perfect diction). The study started with subjects beginning their schooling in 1998. 1
Rits is a department of the Erasmus Institute Brussels. The school “Rits” is well known, but the word “Rits” has lost his original meaning and comes from HRITCS (Hoger RijksInstituut voor Toneel en Cultuurspreidingstechnieken).
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Vocal hygiene education and voice-training protocol Subjects attended the lectures “voice and technique” where anatomy and physiology of the vocal tract, vocal hygiene, and rules of pronunciation and diction are explained. Vocal hygiene education was emphasized, and the consequences of tobacco smoke (vocal health), late meals (danger of reflux), vocal abuse (loud speaking and the use of too low or too high pitch), and stress affecting the voice were explained. Students were recommended to take care of their voices. The lectures amounted to 30 hours (Table 1) and were instructed in the auditorium for radio and actor students in the first 3 months of year 1. After 9 months, students were obliged to pass a theoretical examination on this material. This course was not repeated in the second school year. In the technical workshops, students are trained in the use of their voices in groups of five to eight individuals. Every group received 30 hours technical voice training a year. The parameters of the voice training are presented in a strict order. Basic skills are taught in year 1. In the first 2 months, relaxation, natural posture, and healthy breathing are trained (2 hours/week). The drilling of a vivid and active articulation, a basic condition for a healthy and forward voice production (1 hour/week), and further exercises on voice projection are the issue throughout the rest of the school year. The last phase (year 2) included the training of the voice parameters loudness, pitch, and resonance, and they were taught in the first 5 months of the school year. The workshops lasted for 30 hours a year, and students were evaluated by means of performance tasks. The theoretical framework of the training program is based on the concept of Coblenzer and Muhar8 and our own experience.9 In order to bridge the gap between theory and practice, several radio and drama projects are coached (30 hours) by an experienced speech and language pathologist (SLP). The vocal coaching in the projects was performed in the last months of the school year. In the first year, theater and radio students were coached in the projection of their speech: the intelligibility is a priority. In the second year, the exploration of their voices is the main concern. In the theater projects, the loudness of the voice and the projection of their thoughts are trained. Journal of Voice, Vol. 19, No. 2, 2005
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BERNADETTE TIMMERMANS ET AL TABLE 1. The Different Stages of the Voice Training Program in Year 1 and in Year 2
Lesson type
Different phases
Hours/year
YEAR 1
October November
December January February March April May June
Lectures
vocal hygiene education
30
Workshops
posture/breathing
30
drilling of vivid articulation, voice projection
Coaching
voice coaching in projects
YEAR 2
October November
Workshops
loudness, pitch, resonance: voice projection
December January February March April May June
Coaching
In the radio projects, the different styles of presentation are explored; for example, pop radio needs a higher voice, and journal reading needs a low voice and an “intelligent” presentation. The training was conducted by three speech and language pathologists (one SLP for the radio directors, one for the actors, and one for both groups). Voice assessment protocol Data collection was based on the guidelines of the multidimensional voice assessment protocol as proposed by the ELS.2 The first assessment was carried out in October 1998 (further called Time 1), the second “reassessment” was in June 1999 (further called Time 2), and the third assessment was in May 2000 (further called Time 3). The following set of data was collected for each subject: perceptual evaluation by the investigator, acoustic parameters, and an aerodynamic parameter and self-evaluation by the subject. Videolaryngostroboscopy was carried out at the beginning of the study (Time 1) to inspect the vocal fold vibration. A questionnaire on daily habits was administered to record daily habits such as smoking, eating, vocal abuse, and stress affecting the voice. These topics were chosen as the literature portrayed the artistic and media-oriented population as vocally abusive, subject to stress, and irregular working hours as a result of their professional duties.10 Journal of Voice, Vol. 19, No. 2, 2005
30
30 voice coaching in projects
30
The perceptual evaluation was performed using the GRBAS scale as designed by Hirano.4 Each scale is rated as 0 (normal), 1 (slight), 2 (moderate), and 3 (severe). The voices were judged by an experienced SLP and rated using a live voice situation. Videolaryngostroboscopy was carried out using a 90⬚ Von Stuckrad rigid endoscope and a stroboscopic light source (Wolf stroboscope type 5052; Wolf Co., Knittlingen, Germany) to detect as well the pathological condition of the vocal fold epithelium (Vocal Fold Nodules, Sulcus Glottidis) and its vibratory characteristics. The ELS protocol was respected, although the vibratory characteristics were not relevant in this study. Videolaryngostroboscopy was performed at the beginning of the study, and because of financial considerations, it was repeated at the end of the study for subjects with lesions only. The vibratory characteristics of the vocal folds were scored on the parameters according to the ELS protocol: the degree of glottal closure (GC), the type of GC, the quality of the mucosal wave (MW), and the regularity (R) and the symmetry of the movement of the vocal folds. Each scale is rated as 0 (normal), 1 (slight), 2 (moderate), and 3 (severe). In order to simplify the procedure, only the data of the GC and the MW were represented. The strobe raters were blind to the status of the subjects. The aerodynamic measurement was determined by the maximum phonation time (MPT). After a maximal inspiration, a vowel sound /a/ at habitual
PROFESSIONAL VOICE USER TRAINING loudness and pitch was sustained. A stopwatch registered the length of time. Each subject accomplished three MPT trials, of which the best score was selected. Of each subject, a voice sample of 5 seconds was recorded on Digital Audio Tape (DAT Recorder Sony TCD-D100 and Sony microphone ECM-7171; Sony Corporation, Tokyo, Japan). Mouth to microphone distance was set at 30 cm, and the microphone and the subjects’ position were monitored by the instructor during the recording. One midvowel segment on a sustained /a/—at habitual loudness and pitch—was used and 1 second was analyzed. Obtained measurements are (1) Lowest Intensity (dB), (2) Highest Frequency (Hz), and (3) Jitter (%). Sound pressure levels were recorded in decibel (A) units by means of a Sound Level Meter of Bruel & Kjaer Type 2203 (Naerum, Denmark) that was calibrated with the standard procedure of Bruel & Kjaer. Frequency analysis was performed by means of the Voice Analysis Option of the Computerized Speech Lab, (model 4305; Kay Elemetrics Corporation, Lincoln Park, NJ). The acoustic analysis (Jitter %) was performed by the Multi Dimensional Voice Program of the Computerized Speech Lab (MDVP, model 4305; Kay Elemetrics Corporation). The DSI3 was calculated to obtain an overall measure of voice quality. The DSI is based on the weighted combination of the following selected set of voice measurements: Highest Frequency (FoH— Hz), Lowest Intensity (IL—dB), MPT—s, and Jitter—%. The DSI is the most optimal combination of independent variables that best reflects the degree of dysphonia as expressed by the G from the GRBAS scale. It is constructed as DSI ⫽ (0.13 × MPT) ⫹ (0.0053 × FoH) – (0.26 × IL) ⫹ (1.18 × Jitter) ⫹ 12.4. The DSI for perceptually normal voices equals ⫹5 and for severely dysphonic voices ⫺5. The more negative the patients’ index, the worse is the voice quality. A DSI of 1.6 is the cutoff score for perceptual normal voices.3 The psychosocial impact of the voice, as perceived by the subject, was measured by means of the validated Dutch translation of the Voice Handicap Index.5,11 The VHI questionnaire assesses the subject’s perception of disability, handicap, and distress because of voice difficulties. The VHI has three
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subscales: the Functional subscale (VHI F) referring to the voice disorder, the Emotional subscale (VHI E) referring to the affective responses to a voice disorder, and the Physical subscale (VHI P) referring to laryngeal discomfort and voice output. The VHI T reflects the Total score. Jacobson et al5 found that a mid-dysphonia corresponds to a VHI T score of 33, a moderate dysphonia to a VHI T of 44, and a severe dysphonia to a VHI T of 61. A questionnaire on daily habits (included in the appendix) was administered to record “bad” habits such as smoking, late meals, vocal abuse, and stress affecting the voice. The smoking topic was added because of its negative influence on vocal health and the supposition that a lot of them smoked.1 Subjects indicated the number of late meals a week (ranging from 0 to 7); smoking, vocal abuse, and stress were reported by marking yes or no. Statistics Data were analysed with SPSS V11 (SPSS Corporation, Chicago, IL). The main purpose of the investigation was to evaluate the effect of the voice-training program over time. The results of the variables DSI, Jitter, IL, F0H, MPT, VHI T, VHI P, VHI F, and VHI E were investigated with a repeated measures analysis of variance test. The post hoc Tukey multiple comparison test was used to study the effect of the training in and between the different training periods. The Kolmogorov–Smirnov test was used to investigate the normal distribution of the variables. The G score and the variables of the daily habit questionnaire (the presence of smoking, stress, vocal abuse, and the amount of late meals a week) were analyzed by the Friedman test that was used to calculate significant differences over time in each training period. RESULTS AND DISCUSSION Table 2 presents the mean and standard error (SE) of the DSI and its variables, the VHI, and the subscores in Time 1, Time 2, and Time 3. The DSI score improves from 2 to 3.7 in Time 2 and to 4.6 in Time 3 (Figure 1). Timmermans et al6,7 showed that these results are obtained by time and training. The Tukey multiple comparisons test calculated a significant improvement of the DSI score from Time Journal of Voice, Vol. 19, No. 2, 2005
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BERNADETTE TIMMERMANS ET AL TABLE 2. Results of the DSI and Its Variables, the VHI T, and the Subscores from T1 to T3 Trained group (n ⫽ 23)
DSI Jitter (%) FoHigh (Hz) Ilow (dB) MPT (s) VHI T VHI P VHI E VHI F
T1 Mean ⫾ SE
T2 Mean ⫾ SE
T3 Mean ⫾ SE
T1/T2 p value
T2/T3 p value
T1/T3 p value
2 ⫾ 0.4 1.3 ⫾ 0.11 577 ⫾ 40 54 ⫾ 0.9 16 ⫾ 0.7 18.4 ⫾ 1.7 8 ⫾ 0.6 6 ⫾ 0.9 4.3 ⫾ 0.5
3.7 ⫾ 0.4 1 ⫾ 0.11 754 ⫾ 40 52 ⫾ 0.9 16 ⫾ 0.7 19 ⫾ 1.7 8.7 ⫾ 0.6 5.4 ⫾ 0.9 4.6 ⫾ 0.5
4.6 ⫾ 0.4 0.9 ⫾ 0.11 886 ⫾ 40 53 ⫾ 0.9 18 ⫾ 0.6 14.4 ⫾ 1.7 8.3 ⫾ 0.6 3 ⫾ 0.9 3.3 ⫾ 0.5
0.005 0.3 0.009 0.3 1 0.9 0.6 0.9 0.9
0.2 0.6 0.06 0.7 0.05 0.14 0.8 0.09 0.20
⬍0.001 0.05 ⬍0.001 0.8 0.05 0.2 0.9 0.03 0.3
SE ⫽ Standard error ⫽ SD/冪n. DSI: Perceptual normal voices ⫽ ⫹5; severely dysphonic voices ⫽ ⫺5. VHI: Subscores with a maximum of 40 (P,E, F) and the Total score a maximum of 120.
1 to Time 2 (P ⫽ 0.005) and not from Time 2 to Time 3 (P ⫽ 0.2), meaning that the improvement is remarkable after 9 months of voice training. The first training period seems to be the most productive period. However, in the second training period, the voice quality of 15 subjects (65%) still improves. The variables Jitter and MPT ameliorate gradually and are significantly better after 18 months (from Time 1 to Time 3; Jitter and MPT: P ⫽ 0.05). The FoH advances significantly after 9 months of voice training (P ⫽ 0.009), and the IL improves
FIGURE 1. The DSI scores from T1 to T2 and T3. T1: Time 1 (study onset). T2: Time 2 (after 9 months). T3: Time 3 (after 18 months). DSI: perceptual normal voices ⫹5. Journal of Voice, Vol. 19, No. 2, 2005
gradually but the betterment is not significant (P ⫽ 0.8). It is important to note that the presented results are the mean values of the 23 subjects, which does not reflect the individuals with better scores. Seven subjects (30%) of the 23 subjects have DSI scores higher than 5 (with a minimum score of 5.6 to a maximum score of 9.9); 11 subjects (48%) improve their voice quality (with a minimum score of 2.5 to a maximum score of 4.5), and 5 subjects (22%) show a relapse in voice quality or an unchanged voice quality (with a minimum score of 0.9 to a maximum score of 4). In the first training year, an appropriate vocal technique is trained (natural posture and relaxation, breathing support, forward articulation, and voice projection), and this is the agent of the voice quality change. Subjects realize that the correct use of their voices and an economic breathing technique is necessary for an intelligible communication. For the first time in their lives, they experience that proper breathing; forward voicing and vivid articulation are influencing each other: if one parameter fails, the other parameters are immediately affected, resulting in a poor communication. The videolaryngostroboscopy was performed at Time 1, and only subjects with lesions were reexamined at the end of the study. The strobe rater detected four subjects with an incomplete GC and three subjects with a disturbed MW. From the 23 subjects, 1 subject suffered with vocal fold nodules, 1 with a
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TABLE 3. (A) The G Scores and DSI Scores of the Four Subjects With Lesions at T1 to T3 Lesions T1
Lesions T3
G score T1/T3
DSI score T1/T3
Vocal fold nodules Erythema and edema Erythema and edema Erythema and edema ⫹ sulcus
no lesion no change no lesion /
from from from from
from from from from
G2 G1 G2 G2
to to to to
G1 G1 G1 G1
⫺0.9 to 3.1 1 to 0.9 0.2 to 4 0.9 to 3.9
VHI score T1/T3 from from from from
39 to 13 to 11 to 44 to
27 5 14 37
T1: Time 1 (study onset). T2: Time 2 (after 9 months). T3: Time 3 (after 18 months).
TABLE 3. (B) The G scores in T1, T2, and T3 Trained group (n ⫽ 23)
G score 0 1 2 3
T1
T2
T3
n 14 4 5 /
n 14 5 4
n 15 8 0 /
T1: Time 1 (study onset). T2: Time 2 (after 9 months). T3: Time 3 (after 18 months).
sulcus glottidis combined with erythema and edema, and 2 subjects with edema and erythema (Table 3A). The perceptual evaluation of the four subjects with a lesion changed to G1, and the DSI score ameliorated in three subjects. The lesions of two subjects disappeared, one subject could not be examined, and one subjects’ vocal folds status remained the same (erythema and edema). The G score (Table 3B) confirms the improved calculated voice quality after 18 months, as G2 scores no longer occur. The perceptual evaluation changed significantly after 18 months (P ⫽ 0.04). The results demonstrate that perceived voice quality change is scored after 18 months only, illustrating that the categorical severity rating does not permit to score minimal changes in voice quality. The group of eight slightly dysphonic (G1) subjects in Time 3 consists of the four students with a lesion, two with a functional dysphonia and two students with a cold or fatigue in the third assessment only (Table 3B). Examiner bias could have influenced the perceptual data as only one investigator performed the evaluation, although the results do not confirm this impression. That is the reason why the objective results are emphasized.
The results of the VHI (Table 2) improve but remain relatively high. The VHI T scores changed from 18.4/120 in Time 1, 19/120 in Time 2, and resulting in 14.4/120 in Time 3 (Figure 2); the differences are not significant. The mean scores of the VHI P and VHI F show little or no improvement. The mean VHI E score, on the contrary, is the only subscore that improves significantly (P ⫽ 0.003) after 18 months. The presented results of the VHI are the mean values of the 23 subjects, without an indication of the subjects with good scores. For the VHI T, 12 subjects (52%) score between 0 and 10, 5 subjects (22%) indicate improvement but score high between 23 and 33, and 6 subjects (26%) relapse. Three of the subjects with lesions (Table 3A) have high VHI
FIGURE 2. The VHI scores from T1 to T2 and T3. T1: Time 1 (study onset). T2: Time 2 (after 9 months). T3: Time 3 (after 18 months). VHI: Total score of the VHI with a maximum score of 120. Journal of Voice, Vol. 19, No. 2, 2005
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BERNADETTE TIMMERMANS ET AL
T scores. The results of the VHI P, the Physical subscale, referring to laryngeal discomfort and voice output, show a setback in 57% (n ⫽ 13) of the subjects: eight subjects with scores between 12 and 18 and five subjects with scores between 3 and 8. The remaining 10 subjects improve and score between 0 and 10. Referring to Jacobson et al,5 a mild dysphonia corresponds to a VHI T of 33/120, and De Bodt et al11 reported a mean score of 4.7 for subjects with normal voices (pathology free). These findings put a VHI score of 14 into perspective and indicate that this score is not pathologically high. Apart from the subjects with lesions, there are no objective reasons to judge that the voice handicap is problematic. In the previous studies, Timmermans et al6,7 calculated that the betterment of the VHI scores is caused by time and not by training. In a course of 2 years, students become more mature. At the age of 18–19 years, these youngsters are confronted with their own personality; certainly in this artistic environment, personal reflection and a strong commitment is of major importance. This evolution and the acquired insights in voice production could induce a more realistic perception of their voices, and this is probably reflected in the significantly improved VHI E score. We have to realize that these students are confronted with minor dysphonia and therefore that these voice problems cannot be entirely responsible for the high VHI scores. The dependency on their voices in the performance of their jobs and the constant remarks of several teachers on their vocal capacities does affect the students’ perceptions. The authors suspect that the VHI remains high, as the students slowly acquire control over their vocal performances. Students were asked to train the voice, as an element of their study program; they did not request voice training. Their motivation to change or improve their voices is probably lower than someone who asks for training. On the other hand, it has to be stressed that the VHI score is not dramatically high: the voice is falsely experienced as a handicap. In spite of this fear and the awareness that they are absolutely dependent on their voices, they forget to take the appropriate precautions for voice care. Journal of Voice, Vol. 19, No. 2, 2005
TABLE 4. Number and Percentage of Persons Who Smoke, Who Report Stress, Vocal Abuse, and Late Meals in T1, T2, and T3 Trained Group (n ⫽ 23)
Smoke Stress Abuse Late meals
T1 n (%)
T2 n (%)
T3 n (%)
9 4 3 2
9 10 5 9
11 17 3 6
(39%) (17%) (13%) (8%)
(39%) (43%) (21%) (39%)
(48%) (73%) (13%) (26%)
T1: Time 1 (study onset). T2: Time 2 (after 9 months). T3: Time 3 (after 18 months).
Table 4 presents the three subsequent results (Times 1, 2, and 3) of smoking prevalence, vocal abuse, stress, and late meals. The smoking prevalence remains high after 9 and 18 months (from 39% to 48%). Raphael12 states that smoking is always a problem in proper voice care and seems to be popular in the artistic and media environment. Overall, 13% is still vocally abusive and 26% of the subjects instead of the 8% at the beginning of the study eat late. Stress affecting the voice increases dramatically and significantly (P ⬍ 0.001) from 17% to 43% to 73%. This could mean that the lectures in this current format do not lead to permanent habit changes. There is no plausible declaration for the neglected vocal hygiene, and the results of studies on vocal hygiene education are not unambiguous. Some studies are in favor of vocal hygiene (Roy et al13, Chan,14 and Yiu15), whereas Timmermans et al1 and Broaddus-Lawrence et al16 found a relative small impact of vocal hygiene education in “artistic” professional voice users. Van der Merwe et al17 conclude that professional voice users (ie, educators, ministers, and singers) expose themselves to high risk factors and do not conserve their voices. In a previous study, Timmermans et al18 questioned the vocal care of radio students (mean age ⫽ 22) and radio professionals (mean age ⫽ 41). It could be expected that age, maturity, and professional duties turn the vocal hygiene habits in favor. It is not shown that vocal hygiene in radio professionals is better than in radio students, although this could be expected from these professional voice users. These conclusions are surprising, as one could expect that professional voice
PROFESSIONAL VOICE USER TRAINING users are conscious about the voice and therefore take more care of the voice than any other individual would do. CONCLUSION This study shows that a well-organized voicetraining program in future professional voice users results in a significant improvement of voice quality. The training effect is most remarkable after 9 months and seems to consolidate in the subsequent 9 months. This is not the case for vocal hygiene that is not modified as such by this program. Another concept should be formulated to change lifestyle and daily habits. Future vocal professionals have a disproportional perception of their own voices because they realize its importance for their future jobs. A long-term follow-up could be interesting to find out if the results of this voice-training program maintain. REFERENCES 1. Timmermans B, De Bodt MS, Wuyts FL, Boudewijns A, Clement G, Peeters A, et al. Poor voice quality in future elite vocal performers and professional voice users. J Voice. 2002;16:372–381. 2. Dejonckere PH, Bradley P, Clemente P, Cornut G, CrevierBuchman L, Friedrich G, et al. A basic protocol for functional assessment of voice pathology, especially for investigating the efficacy of (phonosurgical) treatments and evaluating new assessment techniques. Eur Arch Otorhinolaryngol. 2001; 258:77–82. 3. Wuyts FL, De Bodt MS, Molenberghs G, Remacle M, Heylen L, Millet B, et al. The Dysphonia Severity Index: an objective measure of vocal quality based on a multiparameter approach. J Speech Lang Hear Res. 2000;43: 796–809. 4. Hirano M. Clinical application of voice tests. In: NIDCD, editor. Assessment of Speech and Voice Production. Bethesda, MD: NIDCD; 1990:196–203. 5. Jacobson BH, Johnson A, Grywalski C, Silbergleit A, Jacobson G, Benninger MS, et al. The Voice Handicap Index (VHI): development and validation. Am J Speech Lang Pathol. 1997;6:66–67.
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6. Timmermans B, De Bodt M, Wuyts F, Van de Heyning P. Voice quality change in future professional voice users after nine months voice training. Eur Arch Otolaryngol. 2004;261(1):1–5. 7. Timmermans B, De Bodt M, Wuyts F, Van de Heyning P. Training outcome in future professional voice users after eighteen months voice training. Folia Phoniat. 2004;56: 120–129. 8. Coblenzer H, Muhar F. Atem und Stimme. Anleitung zum guten sprechten. Wien, Germany: Osterreicher Bundes Verlag & Ho¨lder-Pichler-Tempsky; 2002. 9. Decoster W, Timmermans B, Schaerlaekens AM, Debruye F. Verzorg je stem. Vademecum voor de professionele stemgebruiker. Deurne: Wolters Plantyn; 2000. 10. Hollien H. That golden voice—talent or training? J Voice. 1993;7:195–205. 11. De Bodt MS, Jacobson B, Musschoot S, Zaman S, Heylen L, Mertens F, et al. De Voice Handicap Index. Een instrument voor het kwantificeren van de psychosociale consequenties van stemstoornissen. Logopedie. 2000;13: 29–33. 12. Raphael B. Special considerations relating to members of the acting profession. In: Sataloff R, editor. Professional Voice. The Science and Art of Clinical Care. New York: Raven Press; 1991:85–89. 13. Roy N, Weinrich B, Gray S, Tanner K, Toledo S, Dove H, et al. Voice amplification versus vocal hygiene instruction for teachers with voice disorders: a treatment outcome study. J Speech Lang Hear Res. 2002;45(4):625–638. 14. Chan R. Does the voice improve with the vocal hygiene education? A study of some instrumental voice measures in a group of kindergarten teachers. J Voice. 1994;8(3): 297–291. 15. Yiu E. Impact and prevention of voice problems in the teaching profession: embracing the consumers’ view. J Voice. 2002;16(2):215–228. 16. Broaddus-Lawrence P, Treole K, McCabe R, Allen R, Toppin L. The effects of preventive vocal hygiene education on the vocal hygiene habits and perceptual vocal characteristics of training singers. J Voice. 2000;14(1):58–71. 17. Van der Merwe A, Van Tonder M, Pretorius E, Crous H. Voice problems in some groups of professional users of voice: implications for prevention. S Afr J Commun Disord. 1996;43:41–51. 18. Timmermans B, De Bodt M, Wuyts F, Van de Heyning P. Vocal hygiene in future professional voice users and in professional voice users. Logoped Phoniat Vocol. 2003;28: 127–132.
Journal of Voice, Vol. 19, No. 2, 2005
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Journal of Voice, Vol. 19, No. 2, 2005
BERNADETTE TIMMERMANS ET AL
Summary: The goal of this study is to analyze and evaluate the effectiveness of a voice-training program. Twenty-three professional voice users received voice training for 2 years and vocal hygiene education for 1 year. The voicetraining program consisted of lectures, technical workshops, and vocal coaching. The European Laryngological Society (ELS) protocol, including the Dysphonia Severity Index (DSI) and the Voice Handicap Index (VHI), was applied before and after, respectively, 9 and 18 months of voice training. A questionnaire on daily habits was presented at study onset and after 18 months. The DSI improvement is more significant after 9 months (P ⫽ 0.005) than it is after 18 months (P ⫽ 0.2). On the other hand, the perceptual evaluation remained unchanged after 9 months, whereas it improved significantly after 18 months. The results of the daily habit questionnaire are disturbing: the prevalence of smoking, vocal abuse, stress, and late meals were not influenced by the lectures and remained high. This study emphasizes the need for a well-organized voice-training program that is most effective after 9 months. Regarding the low effectiveness of the vocal hygiene program, the concept needs revision. Key Words: Voice quality—Vocal hygiene—Outcome—Professional voice users—Voice-training program.
INTRODUCTION
Accepted for publication April 26, 2004. From the *Department Rits, Erasmus Institute, Brussels, Belgium; †Faculty of Medicine, Department of Otolaryngology, Head and Neck Surgery and Communication Disorders, University Hospital Antwerp, UA, Belgium. Address correspondence and reprint requests to Bernadette Timmermans, Department of Otolaryngology, Head and Neck Surgery and Communication Disorders, University Hospital Antwerp, UA, Wilrijkstraat, 10, B-2650 Edegem, Belgium. E-mail: [email protected] Journal of Voice, Vol. 19, No. 2, pp. 202–210 0892-1997/$30.00 쑕 2005 The Voice Foundation doi:10.1016/j.jvoice.2004.04.009
This study concentrates on the effectiveness of a voice-training program for 23 future professional voice users, such as actors and radio directors. As this population needs a well-functioning voice, but also a resonant and beautiful voice, everybody expects that this category of professional voice users receives voice training. Nevertheless, scientific research on the training effect is rare.1 In a previous study, Timmermans et al1 assessed 86 voices of future professional voice users by means of the European Laryngological Society protocol 202
PROFESSIONAL VOICE USER TRAINING (ELS)2 and concluded that the vocal characteristics and the self-perception of future professional voice users are not as good as expected. However, after 9 and 18 months of voice training, 46 voices were assessed again and a significantly improved objectively measured voice quality (Dysphonia Severity Index, DSI)3 and a significant betterment of the perceptual evaluation (GRBAS scale, where G stands for grade of overall hoarseness, R for roughness, B for breathiness, A for asthenity, and S for strain)4 were found. The self-assessment (Voice Handicap Index, VHI),5 however, showed that the actor and radio students experience their voices as problematic. In spite of this, they neglect the rules of vocal hygiene as a lot of them smoke, many report stress, abuse the voice, and eat very late because of scholar obligations.6,7 In this study, a comparative analysis of the results of the three assessment moments—at study onset (Time 1), after 9 months (Time 2), and after 18 months (Time 3), was performed to determine the impact of each training phase. Comparing the results over time can reveal important and useful information about the effectiveness of the training program, the optimal period of training, and the effect of vocal hygiene. This information can be helpful in the construction and optimization of a future training program for this population. MATERIALS AND METHODS Subjects Subjects are between 19 and 30 years old and students of the Rits,1 ie, school for audiovisual communication. The 23 subjects (13 males and 10 females) received 18 months of voice training, which is a basic element in their study program. This group, further called the trained group, consists of future actors or radio directors (radio directors create, direct, and present their own radio programs; presentation is desirable but is allowed only with a good voice and perfect diction). The study started with subjects beginning their schooling in 1998. 1
Rits is a department of the Erasmus Institute Brussels. The school “Rits” is well known, but the word “Rits” has lost his original meaning and comes from HRITCS (Hoger RijksInstituut voor Toneel en Cultuurspreidingstechnieken).
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Vocal hygiene education and voice-training protocol Subjects attended the lectures “voice and technique” where anatomy and physiology of the vocal tract, vocal hygiene, and rules of pronunciation and diction are explained. Vocal hygiene education was emphasized, and the consequences of tobacco smoke (vocal health), late meals (danger of reflux), vocal abuse (loud speaking and the use of too low or too high pitch), and stress affecting the voice were explained. Students were recommended to take care of their voices. The lectures amounted to 30 hours (Table 1) and were instructed in the auditorium for radio and actor students in the first 3 months of year 1. After 9 months, students were obliged to pass a theoretical examination on this material. This course was not repeated in the second school year. In the technical workshops, students are trained in the use of their voices in groups of five to eight individuals. Every group received 30 hours technical voice training a year. The parameters of the voice training are presented in a strict order. Basic skills are taught in year 1. In the first 2 months, relaxation, natural posture, and healthy breathing are trained (2 hours/week). The drilling of a vivid and active articulation, a basic condition for a healthy and forward voice production (1 hour/week), and further exercises on voice projection are the issue throughout the rest of the school year. The last phase (year 2) included the training of the voice parameters loudness, pitch, and resonance, and they were taught in the first 5 months of the school year. The workshops lasted for 30 hours a year, and students were evaluated by means of performance tasks. The theoretical framework of the training program is based on the concept of Coblenzer and Muhar8 and our own experience.9 In order to bridge the gap between theory and practice, several radio and drama projects are coached (30 hours) by an experienced speech and language pathologist (SLP). The vocal coaching in the projects was performed in the last months of the school year. In the first year, theater and radio students were coached in the projection of their speech: the intelligibility is a priority. In the second year, the exploration of their voices is the main concern. In the theater projects, the loudness of the voice and the projection of their thoughts are trained. Journal of Voice, Vol. 19, No. 2, 2005
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BERNADETTE TIMMERMANS ET AL TABLE 1. The Different Stages of the Voice Training Program in Year 1 and in Year 2
Lesson type
Different phases
Hours/year
YEAR 1
October November
December January February March April May June
Lectures
vocal hygiene education
30
Workshops
posture/breathing
30
drilling of vivid articulation, voice projection
Coaching
voice coaching in projects
YEAR 2
October November
Workshops
loudness, pitch, resonance: voice projection
December January February March April May June
Coaching
In the radio projects, the different styles of presentation are explored; for example, pop radio needs a higher voice, and journal reading needs a low voice and an “intelligent” presentation. The training was conducted by three speech and language pathologists (one SLP for the radio directors, one for the actors, and one for both groups). Voice assessment protocol Data collection was based on the guidelines of the multidimensional voice assessment protocol as proposed by the ELS.2 The first assessment was carried out in October 1998 (further called Time 1), the second “reassessment” was in June 1999 (further called Time 2), and the third assessment was in May 2000 (further called Time 3). The following set of data was collected for each subject: perceptual evaluation by the investigator, acoustic parameters, and an aerodynamic parameter and self-evaluation by the subject. Videolaryngostroboscopy was carried out at the beginning of the study (Time 1) to inspect the vocal fold vibration. A questionnaire on daily habits was administered to record daily habits such as smoking, eating, vocal abuse, and stress affecting the voice. These topics were chosen as the literature portrayed the artistic and media-oriented population as vocally abusive, subject to stress, and irregular working hours as a result of their professional duties.10 Journal of Voice, Vol. 19, No. 2, 2005
30
30 voice coaching in projects
30
The perceptual evaluation was performed using the GRBAS scale as designed by Hirano.4 Each scale is rated as 0 (normal), 1 (slight), 2 (moderate), and 3 (severe). The voices were judged by an experienced SLP and rated using a live voice situation. Videolaryngostroboscopy was carried out using a 90⬚ Von Stuckrad rigid endoscope and a stroboscopic light source (Wolf stroboscope type 5052; Wolf Co., Knittlingen, Germany) to detect as well the pathological condition of the vocal fold epithelium (Vocal Fold Nodules, Sulcus Glottidis) and its vibratory characteristics. The ELS protocol was respected, although the vibratory characteristics were not relevant in this study. Videolaryngostroboscopy was performed at the beginning of the study, and because of financial considerations, it was repeated at the end of the study for subjects with lesions only. The vibratory characteristics of the vocal folds were scored on the parameters according to the ELS protocol: the degree of glottal closure (GC), the type of GC, the quality of the mucosal wave (MW), and the regularity (R) and the symmetry of the movement of the vocal folds. Each scale is rated as 0 (normal), 1 (slight), 2 (moderate), and 3 (severe). In order to simplify the procedure, only the data of the GC and the MW were represented. The strobe raters were blind to the status of the subjects. The aerodynamic measurement was determined by the maximum phonation time (MPT). After a maximal inspiration, a vowel sound /a/ at habitual
PROFESSIONAL VOICE USER TRAINING loudness and pitch was sustained. A stopwatch registered the length of time. Each subject accomplished three MPT trials, of which the best score was selected. Of each subject, a voice sample of 5 seconds was recorded on Digital Audio Tape (DAT Recorder Sony TCD-D100 and Sony microphone ECM-7171; Sony Corporation, Tokyo, Japan). Mouth to microphone distance was set at 30 cm, and the microphone and the subjects’ position were monitored by the instructor during the recording. One midvowel segment on a sustained /a/—at habitual loudness and pitch—was used and 1 second was analyzed. Obtained measurements are (1) Lowest Intensity (dB), (2) Highest Frequency (Hz), and (3) Jitter (%). Sound pressure levels were recorded in decibel (A) units by means of a Sound Level Meter of Bruel & Kjaer Type 2203 (Naerum, Denmark) that was calibrated with the standard procedure of Bruel & Kjaer. Frequency analysis was performed by means of the Voice Analysis Option of the Computerized Speech Lab, (model 4305; Kay Elemetrics Corporation, Lincoln Park, NJ). The acoustic analysis (Jitter %) was performed by the Multi Dimensional Voice Program of the Computerized Speech Lab (MDVP, model 4305; Kay Elemetrics Corporation). The DSI3 was calculated to obtain an overall measure of voice quality. The DSI is based on the weighted combination of the following selected set of voice measurements: Highest Frequency (FoH— Hz), Lowest Intensity (IL—dB), MPT—s, and Jitter—%. The DSI is the most optimal combination of independent variables that best reflects the degree of dysphonia as expressed by the G from the GRBAS scale. It is constructed as DSI ⫽ (0.13 × MPT) ⫹ (0.0053 × FoH) – (0.26 × IL) ⫹ (1.18 × Jitter) ⫹ 12.4. The DSI for perceptually normal voices equals ⫹5 and for severely dysphonic voices ⫺5. The more negative the patients’ index, the worse is the voice quality. A DSI of 1.6 is the cutoff score for perceptual normal voices.3 The psychosocial impact of the voice, as perceived by the subject, was measured by means of the validated Dutch translation of the Voice Handicap Index.5,11 The VHI questionnaire assesses the subject’s perception of disability, handicap, and distress because of voice difficulties. The VHI has three
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subscales: the Functional subscale (VHI F) referring to the voice disorder, the Emotional subscale (VHI E) referring to the affective responses to a voice disorder, and the Physical subscale (VHI P) referring to laryngeal discomfort and voice output. The VHI T reflects the Total score. Jacobson et al5 found that a mid-dysphonia corresponds to a VHI T score of 33, a moderate dysphonia to a VHI T of 44, and a severe dysphonia to a VHI T of 61. A questionnaire on daily habits (included in the appendix) was administered to record “bad” habits such as smoking, late meals, vocal abuse, and stress affecting the voice. The smoking topic was added because of its negative influence on vocal health and the supposition that a lot of them smoked.1 Subjects indicated the number of late meals a week (ranging from 0 to 7); smoking, vocal abuse, and stress were reported by marking yes or no. Statistics Data were analysed with SPSS V11 (SPSS Corporation, Chicago, IL). The main purpose of the investigation was to evaluate the effect of the voice-training program over time. The results of the variables DSI, Jitter, IL, F0H, MPT, VHI T, VHI P, VHI F, and VHI E were investigated with a repeated measures analysis of variance test. The post hoc Tukey multiple comparison test was used to study the effect of the training in and between the different training periods. The Kolmogorov–Smirnov test was used to investigate the normal distribution of the variables. The G score and the variables of the daily habit questionnaire (the presence of smoking, stress, vocal abuse, and the amount of late meals a week) were analyzed by the Friedman test that was used to calculate significant differences over time in each training period. RESULTS AND DISCUSSION Table 2 presents the mean and standard error (SE) of the DSI and its variables, the VHI, and the subscores in Time 1, Time 2, and Time 3. The DSI score improves from 2 to 3.7 in Time 2 and to 4.6 in Time 3 (Figure 1). Timmermans et al6,7 showed that these results are obtained by time and training. The Tukey multiple comparisons test calculated a significant improvement of the DSI score from Time Journal of Voice, Vol. 19, No. 2, 2005
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BERNADETTE TIMMERMANS ET AL TABLE 2. Results of the DSI and Its Variables, the VHI T, and the Subscores from T1 to T3 Trained group (n ⫽ 23)
DSI Jitter (%) FoHigh (Hz) Ilow (dB) MPT (s) VHI T VHI P VHI E VHI F
T1 Mean ⫾ SE
T2 Mean ⫾ SE
T3 Mean ⫾ SE
T1/T2 p value
T2/T3 p value
T1/T3 p value
2 ⫾ 0.4 1.3 ⫾ 0.11 577 ⫾ 40 54 ⫾ 0.9 16 ⫾ 0.7 18.4 ⫾ 1.7 8 ⫾ 0.6 6 ⫾ 0.9 4.3 ⫾ 0.5
3.7 ⫾ 0.4 1 ⫾ 0.11 754 ⫾ 40 52 ⫾ 0.9 16 ⫾ 0.7 19 ⫾ 1.7 8.7 ⫾ 0.6 5.4 ⫾ 0.9 4.6 ⫾ 0.5
4.6 ⫾ 0.4 0.9 ⫾ 0.11 886 ⫾ 40 53 ⫾ 0.9 18 ⫾ 0.6 14.4 ⫾ 1.7 8.3 ⫾ 0.6 3 ⫾ 0.9 3.3 ⫾ 0.5
0.005 0.3 0.009 0.3 1 0.9 0.6 0.9 0.9
0.2 0.6 0.06 0.7 0.05 0.14 0.8 0.09 0.20
⬍0.001 0.05 ⬍0.001 0.8 0.05 0.2 0.9 0.03 0.3
SE ⫽ Standard error ⫽ SD/冪n. DSI: Perceptual normal voices ⫽ ⫹5; severely dysphonic voices ⫽ ⫺5. VHI: Subscores with a maximum of 40 (P,E, F) and the Total score a maximum of 120.
1 to Time 2 (P ⫽ 0.005) and not from Time 2 to Time 3 (P ⫽ 0.2), meaning that the improvement is remarkable after 9 months of voice training. The first training period seems to be the most productive period. However, in the second training period, the voice quality of 15 subjects (65%) still improves. The variables Jitter and MPT ameliorate gradually and are significantly better after 18 months (from Time 1 to Time 3; Jitter and MPT: P ⫽ 0.05). The FoH advances significantly after 9 months of voice training (P ⫽ 0.009), and the IL improves
FIGURE 1. The DSI scores from T1 to T2 and T3. T1: Time 1 (study onset). T2: Time 2 (after 9 months). T3: Time 3 (after 18 months). DSI: perceptual normal voices ⫹5. Journal of Voice, Vol. 19, No. 2, 2005
gradually but the betterment is not significant (P ⫽ 0.8). It is important to note that the presented results are the mean values of the 23 subjects, which does not reflect the individuals with better scores. Seven subjects (30%) of the 23 subjects have DSI scores higher than 5 (with a minimum score of 5.6 to a maximum score of 9.9); 11 subjects (48%) improve their voice quality (with a minimum score of 2.5 to a maximum score of 4.5), and 5 subjects (22%) show a relapse in voice quality or an unchanged voice quality (with a minimum score of 0.9 to a maximum score of 4). In the first training year, an appropriate vocal technique is trained (natural posture and relaxation, breathing support, forward articulation, and voice projection), and this is the agent of the voice quality change. Subjects realize that the correct use of their voices and an economic breathing technique is necessary for an intelligible communication. For the first time in their lives, they experience that proper breathing; forward voicing and vivid articulation are influencing each other: if one parameter fails, the other parameters are immediately affected, resulting in a poor communication. The videolaryngostroboscopy was performed at Time 1, and only subjects with lesions were reexamined at the end of the study. The strobe rater detected four subjects with an incomplete GC and three subjects with a disturbed MW. From the 23 subjects, 1 subject suffered with vocal fold nodules, 1 with a
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TABLE 3. (A) The G Scores and DSI Scores of the Four Subjects With Lesions at T1 to T3 Lesions T1
Lesions T3
G score T1/T3
DSI score T1/T3
Vocal fold nodules Erythema and edema Erythema and edema Erythema and edema ⫹ sulcus
no lesion no change no lesion /
from from from from
from from from from
G2 G1 G2 G2
to to to to
G1 G1 G1 G1
⫺0.9 to 3.1 1 to 0.9 0.2 to 4 0.9 to 3.9
VHI score T1/T3 from from from from
39 to 13 to 11 to 44 to
27 5 14 37
T1: Time 1 (study onset). T2: Time 2 (after 9 months). T3: Time 3 (after 18 months).
TABLE 3. (B) The G scores in T1, T2, and T3 Trained group (n ⫽ 23)
G score 0 1 2 3
T1
T2
T3
n 14 4 5 /
n 14 5 4
n 15 8 0 /
T1: Time 1 (study onset). T2: Time 2 (after 9 months). T3: Time 3 (after 18 months).
sulcus glottidis combined with erythema and edema, and 2 subjects with edema and erythema (Table 3A). The perceptual evaluation of the four subjects with a lesion changed to G1, and the DSI score ameliorated in three subjects. The lesions of two subjects disappeared, one subject could not be examined, and one subjects’ vocal folds status remained the same (erythema and edema). The G score (Table 3B) confirms the improved calculated voice quality after 18 months, as G2 scores no longer occur. The perceptual evaluation changed significantly after 18 months (P ⫽ 0.04). The results demonstrate that perceived voice quality change is scored after 18 months only, illustrating that the categorical severity rating does not permit to score minimal changes in voice quality. The group of eight slightly dysphonic (G1) subjects in Time 3 consists of the four students with a lesion, two with a functional dysphonia and two students with a cold or fatigue in the third assessment only (Table 3B). Examiner bias could have influenced the perceptual data as only one investigator performed the evaluation, although the results do not confirm this impression. That is the reason why the objective results are emphasized.
The results of the VHI (Table 2) improve but remain relatively high. The VHI T scores changed from 18.4/120 in Time 1, 19/120 in Time 2, and resulting in 14.4/120 in Time 3 (Figure 2); the differences are not significant. The mean scores of the VHI P and VHI F show little or no improvement. The mean VHI E score, on the contrary, is the only subscore that improves significantly (P ⫽ 0.003) after 18 months. The presented results of the VHI are the mean values of the 23 subjects, without an indication of the subjects with good scores. For the VHI T, 12 subjects (52%) score between 0 and 10, 5 subjects (22%) indicate improvement but score high between 23 and 33, and 6 subjects (26%) relapse. Three of the subjects with lesions (Table 3A) have high VHI
FIGURE 2. The VHI scores from T1 to T2 and T3. T1: Time 1 (study onset). T2: Time 2 (after 9 months). T3: Time 3 (after 18 months). VHI: Total score of the VHI with a maximum score of 120. Journal of Voice, Vol. 19, No. 2, 2005
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T scores. The results of the VHI P, the Physical subscale, referring to laryngeal discomfort and voice output, show a setback in 57% (n ⫽ 13) of the subjects: eight subjects with scores between 12 and 18 and five subjects with scores between 3 and 8. The remaining 10 subjects improve and score between 0 and 10. Referring to Jacobson et al,5 a mild dysphonia corresponds to a VHI T of 33/120, and De Bodt et al11 reported a mean score of 4.7 for subjects with normal voices (pathology free). These findings put a VHI score of 14 into perspective and indicate that this score is not pathologically high. Apart from the subjects with lesions, there are no objective reasons to judge that the voice handicap is problematic. In the previous studies, Timmermans et al6,7 calculated that the betterment of the VHI scores is caused by time and not by training. In a course of 2 years, students become more mature. At the age of 18–19 years, these youngsters are confronted with their own personality; certainly in this artistic environment, personal reflection and a strong commitment is of major importance. This evolution and the acquired insights in voice production could induce a more realistic perception of their voices, and this is probably reflected in the significantly improved VHI E score. We have to realize that these students are confronted with minor dysphonia and therefore that these voice problems cannot be entirely responsible for the high VHI scores. The dependency on their voices in the performance of their jobs and the constant remarks of several teachers on their vocal capacities does affect the students’ perceptions. The authors suspect that the VHI remains high, as the students slowly acquire control over their vocal performances. Students were asked to train the voice, as an element of their study program; they did not request voice training. Their motivation to change or improve their voices is probably lower than someone who asks for training. On the other hand, it has to be stressed that the VHI score is not dramatically high: the voice is falsely experienced as a handicap. In spite of this fear and the awareness that they are absolutely dependent on their voices, they forget to take the appropriate precautions for voice care. Journal of Voice, Vol. 19, No. 2, 2005
TABLE 4. Number and Percentage of Persons Who Smoke, Who Report Stress, Vocal Abuse, and Late Meals in T1, T2, and T3 Trained Group (n ⫽ 23)
Smoke Stress Abuse Late meals
T1 n (%)
T2 n (%)
T3 n (%)
9 4 3 2
9 10 5 9
11 17 3 6
(39%) (17%) (13%) (8%)
(39%) (43%) (21%) (39%)
(48%) (73%) (13%) (26%)
T1: Time 1 (study onset). T2: Time 2 (after 9 months). T3: Time 3 (after 18 months).
Table 4 presents the three subsequent results (Times 1, 2, and 3) of smoking prevalence, vocal abuse, stress, and late meals. The smoking prevalence remains high after 9 and 18 months (from 39% to 48%). Raphael12 states that smoking is always a problem in proper voice care and seems to be popular in the artistic and media environment. Overall, 13% is still vocally abusive and 26% of the subjects instead of the 8% at the beginning of the study eat late. Stress affecting the voice increases dramatically and significantly (P ⬍ 0.001) from 17% to 43% to 73%. This could mean that the lectures in this current format do not lead to permanent habit changes. There is no plausible declaration for the neglected vocal hygiene, and the results of studies on vocal hygiene education are not unambiguous. Some studies are in favor of vocal hygiene (Roy et al13, Chan,14 and Yiu15), whereas Timmermans et al1 and Broaddus-Lawrence et al16 found a relative small impact of vocal hygiene education in “artistic” professional voice users. Van der Merwe et al17 conclude that professional voice users (ie, educators, ministers, and singers) expose themselves to high risk factors and do not conserve their voices. In a previous study, Timmermans et al18 questioned the vocal care of radio students (mean age ⫽ 22) and radio professionals (mean age ⫽ 41). It could be expected that age, maturity, and professional duties turn the vocal hygiene habits in favor. It is not shown that vocal hygiene in radio professionals is better than in radio students, although this could be expected from these professional voice users. These conclusions are surprising, as one could expect that professional voice
PROFESSIONAL VOICE USER TRAINING users are conscious about the voice and therefore take more care of the voice than any other individual would do. CONCLUSION This study shows that a well-organized voicetraining program in future professional voice users results in a significant improvement of voice quality. The training effect is most remarkable after 9 months and seems to consolidate in the subsequent 9 months. This is not the case for vocal hygiene that is not modified as such by this program. Another concept should be formulated to change lifestyle and daily habits. Future vocal professionals have a disproportional perception of their own voices because they realize its importance for their future jobs. A long-term follow-up could be interesting to find out if the results of this voice-training program maintain. REFERENCES 1. Timmermans B, De Bodt MS, Wuyts FL, Boudewijns A, Clement G, Peeters A, et al. Poor voice quality in future elite vocal performers and professional voice users. J Voice. 2002;16:372–381. 2. Dejonckere PH, Bradley P, Clemente P, Cornut G, CrevierBuchman L, Friedrich G, et al. A basic protocol for functional assessment of voice pathology, especially for investigating the efficacy of (phonosurgical) treatments and evaluating new assessment techniques. Eur Arch Otorhinolaryngol. 2001; 258:77–82. 3. Wuyts FL, De Bodt MS, Molenberghs G, Remacle M, Heylen L, Millet B, et al. The Dysphonia Severity Index: an objective measure of vocal quality based on a multiparameter approach. J Speech Lang Hear Res. 2000;43: 796–809. 4. Hirano M. Clinical application of voice tests. In: NIDCD, editor. Assessment of Speech and Voice Production. Bethesda, MD: NIDCD; 1990:196–203. 5. Jacobson BH, Johnson A, Grywalski C, Silbergleit A, Jacobson G, Benninger MS, et al. The Voice Handicap Index (VHI): development and validation. Am J Speech Lang Pathol. 1997;6:66–67.
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6. Timmermans B, De Bodt M, Wuyts F, Van de Heyning P. Voice quality change in future professional voice users after nine months voice training. Eur Arch Otolaryngol. 2004;261(1):1–5. 7. Timmermans B, De Bodt M, Wuyts F, Van de Heyning P. Training outcome in future professional voice users after eighteen months voice training. Folia Phoniat. 2004;56: 120–129. 8. Coblenzer H, Muhar F. Atem und Stimme. Anleitung zum guten sprechten. Wien, Germany: Osterreicher Bundes Verlag & Ho¨lder-Pichler-Tempsky; 2002. 9. Decoster W, Timmermans B, Schaerlaekens AM, Debruye F. Verzorg je stem. Vademecum voor de professionele stemgebruiker. Deurne: Wolters Plantyn; 2000. 10. Hollien H. That golden voice—talent or training? J Voice. 1993;7:195–205. 11. De Bodt MS, Jacobson B, Musschoot S, Zaman S, Heylen L, Mertens F, et al. De Voice Handicap Index. Een instrument voor het kwantificeren van de psychosociale consequenties van stemstoornissen. Logopedie. 2000;13: 29–33. 12. Raphael B. Special considerations relating to members of the acting profession. In: Sataloff R, editor. Professional Voice. The Science and Art of Clinical Care. New York: Raven Press; 1991:85–89. 13. Roy N, Weinrich B, Gray S, Tanner K, Toledo S, Dove H, et al. Voice amplification versus vocal hygiene instruction for teachers with voice disorders: a treatment outcome study. J Speech Lang Hear Res. 2002;45(4):625–638. 14. Chan R. Does the voice improve with the vocal hygiene education? A study of some instrumental voice measures in a group of kindergarten teachers. J Voice. 1994;8(3): 297–291. 15. Yiu E. Impact and prevention of voice problems in the teaching profession: embracing the consumers’ view. J Voice. 2002;16(2):215–228. 16. Broaddus-Lawrence P, Treole K, McCabe R, Allen R, Toppin L. The effects of preventive vocal hygiene education on the vocal hygiene habits and perceptual vocal characteristics of training singers. J Voice. 2000;14(1):58–71. 17. Van der Merwe A, Van Tonder M, Pretorius E, Crous H. Voice problems in some groups of professional users of voice: implications for prevention. S Afr J Commun Disord. 1996;43:41–51. 18. Timmermans B, De Bodt M, Wuyts F, Van de Heyning P. Vocal hygiene in future professional voice users and in professional voice users. Logoped Phoniat Vocol. 2003;28: 127–132.
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