Level of physiological, anatomical and pathological knowledge of the singing voice on the part of professional and amateur singers

Purpose: the knowledge concerning care of the voice on the part of professional and amateur singers in Chile is relevant for voice professionals and also for speech pathologists who work in disorder prevention and voice care. It is important to know if there are differences between both groups regarding the knowledge of voice care. Methods: the “Vocal Awareness Questionnaire for Singers’’ was applied to a sample of 66 singers: 33 professional and 33 amateur singers. Three areas of knowledge were evaluated: anatomy and physiology of the larynx, vocal hygiene and voice pathologies. Results: there were no significant differences in the knowledge of voice care between professional and amateur singers both at a general level and in specific areas of knowledge. The topic of vocal hygiene obtained the highest percentage of correct answers in both groups, while the lowest percentage was in the area of voice pathologies. Conclusions: there were no differences in the level of knowledge on voice care between the professional and amateur singers included in this study. In both groups, the level of knowledge was from low to moderate. This could increase the incidence of vocal pathologies in both groups.


INTRODUCTION
The correct use of the phonation mechanism is important,on the long term, for artists who use their voice as the chosen instrument of their musical career 1 .For this reason, all professional or amateur singers should be familiar with the basic processes involved in voice production.According to Alessandroni et al. 2 , singers lacking a detailed knowledge of the structure of the vocal folds and their principal characteristics, or of the nervous, sensory and motor processes involved in the phonation process, are unable to detect certain problems in their own voice or that of others.A singer 3 or singing teacher 4 possessing a good understanding of the physiology of the vocal cords can more easily visualize their operation and be aware of the basic physiological processes involved.Unfortunately, voice difficulties are common among both voice teachers and singers, even more so than among the general population 5 .
For singers, this knowledge is relevant, because not all voices possessing good esthetic characteristics are healthy voices.Singers lacking adequate knowledge of good vocal techniques are at greater riskof losing their vocal efficiency in the long term 3 .As a result, both singing teachers and singers may be affected by dysphonia, not to mention the fact that certain organic pathologies are caused by untreated muscle tension dysphonia 3 .Not all singers are equally knowledgeable about vocal hygiene and care, or about specific aspects such as laryngeal physiology, vocal techniques, orthe pathologies that may affect the voice of singers 6 .According to Behlau 7 , professional singers are more knowledgeable about the physiology of the vocal apparatus and the processes involved in voice production, as well as good habits of vocal hygiene, as a result of their formal professional education, including their vocal techniques.On the contrary, popular singers are flexible individuals, whose training is often informal or intuitive, they rehearse withoutperforming vocal warm up exercises or applied techniques and havea lower level ofknowledge, as they lack formal training 8 .
Limited experience on the part of the singer also seems to be a factor conducive toignorance of basic care of the voice.Coelho 9 and Rosa et al. 10 say that one of the characteristics commonly found among amateur choir members is their lack of knowledge and their limited experience in comparison with professionals.These problems may be related to thelack of familiarity, on the part of amateur singers, with specific singing techniques 10,11 .
Rosa et al 10 conclude that, at present, the only source of knowledge available to amateur choir members, are the rehearsals provided by their teachers.Techniques such asbreathing exercises, muscular relaxation, vocalizations, andscales fortonal extensionare still commonly used bychoir teachers.However,singers have very limited knowledge ofprocesses taking place at the physiological level andof the effects of the above exercises on voice production 12 .

According
to Estabillo 13 ,vocal abuse and misusemay take placerepeatedly as a result of habits that are harmfulforsingers' health, and of which they are occasionally aware 14 , such as excessive screaming, forced vocalizations, speaking in excess, performing hard glottal attack, inhalation of dust and harmful gases, or badvocal and practice techniques that create hyperfunction of the vocal folds.As a result of vocal misuse and abuse, many singers suffer from chronic laryngitis, vocal nodules, vocal polyps, contact ulcers and/or laryngeal queratosis 13 .
Singers' goodvocal habits and hygieneare alsorelevant forpreventingpathologies.According to Dassie et al. 11 , both lyrical and pop singers have bad habitsforvocal health, such as smoking and drinking, althoughthere aredifferences betweenlyrical and pop singers, aslyrical singerspossess greaterknowledge of vocalperformance and the role of voice therapists.
Knowledge of the physiology of the larynx, of care of the voice and of vocal misuse and abuse are important for the care of the singer's voice.However, these are aspects that have not been addressed in Chile till now.The objective of this study was to evaluate the level of knowledgeabout care of the voice in a sample of Chilean professional and amateur singers by applying the questionnaireVocal Awareness Questionnaire for Singers.

METHODS
This researchwas approved by the Ethics Committee ofUniversidad CatólicadeTemuco.
This study is based on the positivist paradigm.It is a non-experimental, descriptive and cross-sectional study 15 .
The variables considered were the following: gender, age, the items used inthe questionnaire "Vocal awareness questionnaire for Singers'' (Annex 1),and the categories of professional / amateur singer.

Sample
The study considered asample of 66 singers: 33 professional singers and 33 amateur singers in the cities of Temuco and Santiago of Chile.The samplewas selected by convenience sampling.As group distribution criterion, we followed the one suggested byGrape et al. 16 : A Professional Singer[PS] is a singer who has followed formal professional education, includingvocal techniques, with regular classes and rehearsals, andwho receives remuneration for their singing.An Amateur Singers[AS] is a singer who takes singing lessons for non-professional reasons, during their spare time, and receives no remuneration for singing.
We excluded thosesingers that have followed studies and/or specialties invocology, for examplephono-audiologists orear, nose, and throat specialists.

Instrument
Vocal Awareness Questionnaire for Singers: we adapted tothe Spanishlanguage Colleen Braun-Janzen & L. Zeine's questionnaire 6 .The original instrument has 6 items,only threeof which were used in this study: anatomical-physiological knowledge (PART VI; questions 39 to 45, PART VII 56), vocal hygiene (PART V; questions 29 to 38) and pathologies of the singing voice (PART VI; questions 46 to 55,PART VII,57 to 59).The other 3 items were not used as they are not pertinent to this research.

Procedure
Singers were recruited either in person or throughemail.After the study objectives had been explained, including the risks and benefits of the study, each singer signed an informed consent form.Next, each participantcompleted the questionnaireVocal Awareness questionnaire for singers in one of the following manners: in person or online (Google Forms).Each participant was given 15 minutes to complete the questionnaire.
The Chi-squared was used to determine the differences between groups.The variables were subjected to descriptive and inferential analysis, considering a statistical significance value of < 0.05.

RESULTS
The analysis of the data is presented in Tables 1  and 2.
The questions that received the greatest percentage of correct answers included the following: function of the diaphragm (71.2%), the relaxation function of yawning (77.3%), the knowledge of treatment forlaryngitis (96.9%), the damage caused bythroat-clearing (93.9%), the damage caused by speaking in noisy environments (89.3%) and theprogression of vocal nodules (56.1%).
The questionswith the highestpercentage of incorrect answers or lack of knowledge are related to the glottis (75.8%), the function of the cricothyroid muscle (90.9%), the use of the stomach for breathing (59.1%), the function of the soft palate (75.8%), the effects of antihistamines on the voice (50%), the harmful effects of whispering (63.6%) and the effects of speaking in a low tone (77.3%).The itemreceiving the highestpercentages of incorrect answers or lack of knowledge was the one related to vocal pathologies.The singers had no knowledge of the physiopathology ofvocal nodules, its etiology per gender (87.9%), its bilateral presentation (71.2%), the structural characteristics of the nodules (51.5%), their progression and evolution (84.9%), the symptoms associated withvocal nodules (42.4%) and their treatment (39.4).Similarly, singers gave high percentages of incorrect answersinrelation to the effects ofreflux (63.7%), contact ulcers (83.3%) and polyps (72.8%).

DISCUSSION
Professional singers are those who have had formal education or training, and have been subjected over several years to the discipline that is characteristic oftheir profession and their vocal techniques, including regular classes and rehearsals.Behlau 7 states that this group has deeper knowledge of the physiology of the vocal apparatus, of different aspects of voiceproduction, and of habits of vocal hygiene.On the contrary, pop singers are flexible individuals,whose training is intuitive or informal, and they rehearse withoutvocal warm-up exercises or applied techniques 7 .However, ourresults are similar to those of Kwak et al. 16 , which indicate that singers with more advanced studies do not possess significantly greater knowledge of the anatomy of the voice and its physiology.In spite of their relatively low level of knowledge, professional singers recognized that possessing knowledge of the anatomy and physiology of the singing voiceis a pre-requisite for achieving good performance inlyrical singing.This is in agreement with Sielska et al. 17 , who concluded that, for singers, this knowledge is essential forimproving their singing performance.
Both groups gave a high percentage of correct answers in vocal hygiene.In this regard, the type of health care sought by singers may determine their interest in the quality of the voice.Astudy conducted Broaddus-Lawrence et al. 22 These researchers state thatthe singers in their study reported obtaining a high degree of benefits and learnings aftertaking classes and practice sessions in vocal hygiene.
We may mention the following limitations of the present study: the relatively small sample size and the limited control over the online filling of the questionnaire.Therefore, these results should be taken withcaution, and not generalized.It is relevant to mention that one third (33.85%) of the respondents said they do not know what the role of the phono-audiologistis in relation to singing.Although these datawere not analyzed quantitatively, we consider it advisable to conduct further research in this field within the Chilean context.

CONCLUSION
Both professional and amateur singers possess limited to moderate general knowledge in terms of anatomy, physiology and pathology of the singing voice.There were no differences detected between these two groups.
The results of this research indicate that the singers in this study do not possess adequate knowledge about the care of the voice.This is the case even for singers who consider themselves professionals.It seems important that singers be educated in the prevention of vocal pathologies.
It seems advisable for new research to be conducted along these lines, based on different classification and exclusion criteria for professional singers, so as to make it possible toanalyze the differences between singers who have followed formal university-level studies and those who have received informal training.by Petty 18 on professional singers seeking information on vocal health, concludes that singers are more likely to seek information from singing teachers about vocal problems, compared to persons who are not singers, as the latter are more likely to seek advice from doctorsorvoice therapists.The study also indicates that younger singers are more likely to use home remedies in comparison with older singers 18 .Behlau 7 states that amateur and pop singers are more likely to see a speech therapist for general guidance and for vocal hygiene, due to their high rates of vocal misuse and abuse.In the present study, amateur singers were less likely to visit a speech therapist, with dysphonia being the most frequent motive for the visit.Professional singers are more likely to visit a phono-audiologist, with the main motive being voice therapy.According to a study of music students conducted by Kwak et al. 16 , the more-experienced singers do not possess significantly greater knowledge of the anatomy of the voice and its physiology, but they are more interested invisiting anear, nose, and throat specialist, and in learning about vocal pathologies.
Pazo et al. 19 say that, of all singers, lyrical singers are the most likely to avoid vocal abuse and misuse, and their vocal technique is more effective in comparison with pop singers, who neglect good vocal technique.Similarly, Achey et al. 20 state that vocal warm-up exercises are more frequently practiced by opera singers than by pop singers.However, in the present research no marked differences were found in terms of knowledge of vocal techniques, as both groups reportedmoderate to high levels of care of the voice.
The most common pathologies in singers arelaryngitis, vocal nodules and edema.Singers are more likely to perceivevoice symptoms, due to years of selfobservation and the importance accorded to these symptoms bysingers.According to García-López et al. 21singers are more likely to sufferpathologies of the singing voice.Theresearchcarried out by Braun-Jansen 6 indicates that most singers obtain low scores in knowledge about pathologies.This is confirmed in the present study.Similarly, in the item relative to pathologies of the singing voice there is no significant difference between PS and AS in terms ofknowledge of vocal pathology It is interesting to note that 82.8% of the singers in this study evidenced limited or moderate knowledge.Therefore, it can be stated that ahigh percentage of singers requires improvement and education in these areas of knowledge, as indicated by

Table 1 .
Baseline data on professional and amateur singers PS =Professional singers;AS =Amateur singers

Table 2 .
Baseline data on professional and amateur singers

Table 3 .
Level of knowledge on laryngeal anatomy and physiology, vocal hygiene and vocal pathology per group PS =Professional singers;AS = Amateur singers; *Statistical significancefor Chi-square test In diaphragmatic respiration, the stomach is filled with air duringinhalation.I don't know _____ T_____ F ____ 45.The soft palate is raised when making nasal sounds during singing (n, m, and ng) I don't know _____ T_____ F ____ 46.Vocal nodulesare more frequent in females.I don't know _____ T_____ F ____ 47.Vocal nodules are often present in only one vocal cord I don't know _____ T_____ F ____ 48.Vocal nodules are small fibrous lumps usually located in the center of the vocal cord.I don't know _____ T_____ F ____ 49.Vocal nodules, if untreated, may lead to laryngeal cancer.I don't know _____ T_____ F ____ 50.If you havechronic heartburn (Gastroesophageal reflux), you should sleep with your legs slightly raised I don't know _____ T_____ F ____ 51.Contact ulcersare associated with high intensity of the voice I don't know _____ T____F ____ 52.Vocal nodules generally appear gradually I don't know _____ T_____F ____ 53.Polyps in the vocal cordsmay appear suddenly, after a single episode of vocal abuse.I don't know _____ T_____F ____ 54.Contact ulcers are more frequent in males.I don't know _____ T_____ F ____ 55.Chronic heartburn (Gastroesophageal reflux) put you at risk of developing contact ulcers in the vocal cords.I don't know _____ T_____F ____ PART VII.Multiple selection 56.Physiological measurements indicate that a "Support" for singing (with optimum projection and resonance) is closely associated with: 1. _____ I don't know 2. _____ expansion of the rib cage 3. _____reduction of the larynx and stronger closing of the vocal cords.4. _____reduction of the membrane duringinhalation,and compression ofthe abdomenduringexhaling.57.What are the symptoms reported bysingers with small / incipient nodules? 1. _____ I don't know 2. _____ Pain, hoarseness, limited tonal range 3. _____ Hoarseness, difficulty in singing register transitions (vocal passages), and difficulties in fortissimo singing