Hypertonic Aerosols Hydrate Airways Longer and Reduce Acidification Risk with Nonpermeating Cation and Permeating Anion Salts.

Background: Hyperosmolar aerosols appear to promote or suppress upper airway dysfunction caused by dehydration in a composition-dependent manner. We sought to explore this composition dependence experimentally, in an interventional human clinical study, and theoretically, by numerical analysis of upper airway ion and water transport. Methods: In a double-blinded, placebo-controlled clinical study, phonation threshold pressure (PTP) was measured prenasal and postnasal inhalation of hypertonic aerosols of NaCl, KCl, CaCl2, and MgCl2 in seven human subjects. Numerical analysis of water and solute exchanges in the upper airways following deposition of these same aerosols was performed using a mathematical model previously described in the literature. Results: PTP decreased by 9%-22% relative to baseline (p < 0.05) for all salts within the first 30 minutes postadministration, indicating effective laryngeal hydration. Only MgCl2 reduced PTP beyond 90 minutes (21% below baseline at 2 hours postadministration). By numerical analysis, we determined that, while airway water volume up to 15 minutes postdeposition is dictated by osmolarity, after 30 minutes, divalent cation salts, such as MgCl2, better retain airway surface liquid (ASL) volume by slow paracellular clearance of the divalent cation. Fall of CFTR chloride flux with rise in ASL height, a promoter of airway acidification, appears to be a signature of permeating cation (NaCl) and nonpermeating anion (mannitol) aerosol deposition. For hypertonic aerosols that lack permeating cation and include permeating anion (CaCl2 and MgCl2), this acid-trigger signature does not exist. Conclusions: Nonpermeating cation and permeating anion hypertonic aerosols appear to hydrate upper airways longer and, rather than provoke, may reduce laryngeal dysfunction such as cough and bronchoconstriction.

Independence of Vocal Load From Vocal Pathology Across Singing Genres.

OBJECTIVE: To investigate the extent to which vocal load is associated with previous diagnosis of a vocal pathology among four major genres of singers (primarily classical, primarily musical theatre (MT), classical and MT combined, and contemporary commercial music only). STUDY DESIGN: Cross sectional survey. METHODS/DESIGN: An anonymous online survey was sent out to about 1000 professional singers through convenience sampling to touring companies, opera companies, MT companies, agents, directors and musical directors. Social media and email were used to solicit participation in the study. We utilized means and standard deviations for continuous characteristics and frequencies and percentages for categorical characteristics and calculated P values to assess whether differences were statistically significant. RESULTS: A total of 396 professional singers completed the survey, yielding a 40% response rate. Nonprofessional singers, incomplete surveys, and respondents <18 years old were excluded, resulting in a total of 238 responses. Among the 238 participants, 32% were performing in the classical style primarily, 33% in the MTstyle primarily, 15% in both classical and MT, and 20% in other contemporary styles only. Mean age was highest among CV + MT and lowest among primarily MT. Combined classical/MT singers were most likely to have a career outside of vocal performance and continue to work in that career followed by other contemporary styles, classical and MT (P = 0.02). Participants in the combined classical/MT group were most likely to have a reported history of vocal pathology followed by classical, other contemporary styles and MT (not statistically significant). However, participants in the contemporary styles were most likely to have a history of more than one type of vocal pathology. Mean vocal load was highest for the MT group. Other nonsinging factors proved significant such as allergy, hydration and acid reflux. Symptoms of allergies were found to be significant across singing genres. A possible reverse causality association was identified in regards to water intake. Participants with acid reflux were three times more likely to have ever reported vocal pathology. CONCLUSION: Vocal load was not significantly associated with vocal pathology across singing genres; however other nonsinging factors such as allergy, reflux and water intake were significantly associated with vocal pathology.

Vocal Dose and Vocal Demands in Contemporary Musical Theatre.

OBJECTIVE: To document and quantify vocal dose and student-singers' self-assessment during rehearsals for a contemporary musical theater production. METHODS/DESIGN: Six student singers fastened the sensor from the KayPentax APM 3200 dosimeter to the lower neck to capture neck vibration data during their preparation for the musical Wonderland by Frank Wildhorn. Data were collected during 8-hour periods, at four different stages throughout the rehearsal process: beginning (music and choreography learning phase), middle (staging phase), and end (running the entire show/dress rehearsal phase), plus a post-production day once the production had concluded to establish a baseline vocal load. Students concurrently completed the EASE questionnaire1 after each data collection day. RESULTS: The EASE score (Appendix 1) and demographics/perceptual questionnaire (Appendix 2) revealed that all subjects (three males and three females) found the singing role vocally and physically demanding but only two found the roles to be emotionally challenging. The musical score demanded a higher usage of chest register (judged perceptually) than mixed register from lead singers. All subjects' maximum fundamental frequency range exceeded the pitch range required by the score. The mean vibration dose (distance dose) across all singers for rehearsal days was higher for females, 1,100,000 meters, than males, 900,000 meters, and the subjects' self-ratings on the EASE were not correlated with the distance dose. CONCLUSIONS: A review of Wonderland's score and perceptual judgment of the singers' performances revealed extensive use of chest register, with belting and mix vocal strategies being the predominant stylistic choices. Students described the singing roles' vocal and physical requirements as more challenging than the character's emotional components. This pilot study provides information on the vocal dose for lead and ensemble singers in rehearsal for a Contemporary Musical Theatre production. Singers and voice professionals may find dosimetry a valuable tool for monitoring the vocal dose during rehearsals and performances.

Associations of Education and Training with Perceived Singing Voice Function Among Professional Singers.

BACKGROUND: The educational backgrounds of professional singers vary greatly and span from no formal training to advanced degrees in music or theater. Consequently, professional singers have a wide range of knowledge regarding basic voice care. The objective of this study was to examine associations between singers' educational backgrounds, specifically their knowledge of vocal pedagogy and awareness of vocal health, and their perceptions of their current vocal function associated with singing. STUDY DESIGN: Cross sectional survey. METHODS: An online survey was distributed nationwide to over 1,000 self-identifying as a professional singer working full time as a performer. The survey included 54 questions about their background education, performance history, years of professional experience, affiliation to a professional union, general health and wellness, and the Evaluation of the Ability to Sing Easily (EASE), a 20-item scale to assess singers' perceptions of the current status of their vocal function. RESULTS: A total of 396 amateur and professional singers completed the survey yielding a 40% response rate. Of 396 surveys received, 154 were excluded because the respondent was not a professional singer and/or the survey was incomplete and four were excluded because the respondent was <19 years old (396-158 = 238). Of 238, 199 completed the EASE (included in this analysis sample). The respondents identified their primary singing genre(s) as follows: 29% classical, 22% musical theatre, 45% both classical and musical theatre, and 5% other contemporary styles. Overall mean (SD, range) Rasch converted EASE score was 19.9 units (9.0, 0-50). Mean EASE score was 19.6 for primary classical, 22.7 for primary musical theatre, 18.4 for both classical and musical theatre, and 23.3 for other contemporary styles (P = 0.03). Participants who were older, had more years of singing training, had a college degree or higher in music, studied classical singing in an academic or private setting, and those who received education in vocal health had significantly lower (better) EASE scores (P-values <0.05). CONCLUSIONS: Professional singers' perception of their current vocal function differed according to their singing genre, age, extent and type of vocal training and vocal health education. Singing teachers, speech-language pathologists, and physicians could use these results to tailor voice education messages to professional singers. This knowledge could help voice care professionals to educate and treat this elite group of voice users to avoid long-term sequelae from suboptimal voice care.

The Role of Observation and Mentorship in Voice Pedagogy Training.

BACKGROUND: Voice teachers are seeking increasing amounts of pedagogical instructions in the form of observerships, coursework, and clinical experiences. Yet to date there has been no formalized attempt to categorize or set guidelines for these educational experiences. OBJECTIVES: The aim of this study was to investigate (a) the number of hours of observations required or electively completed during pedagogical training (voice lessons, masterclasses) and clinical observations; (b) the number of hours of mentorship (critical observation of a student by a mentor) during pedagogical training; and (c) differences in the training backgrounds of voice teachers based on the level of training, position, and genre. METHODS: We distributed a survey to 700 voice teachers (102 respondents) of various levels from private to university and across age range of students. The surveys contained questions about the role of observation in the teacher's training. We ran descriptive analysis and examined whether the proportion of participants with ≥10 observation and mentorship hours was different for classical versus the other musical genres. RESULTS: The number of respondents actively observing and being observed during their training was low. Most observations occurred within the classical and musical theater singing styles. Mentored critical observations of students were lower across genres than student observations, with the majority of respondents (67-92%) reporting no hours in genres other than classical. For all genres except classical, there was a larger percentage of respondents who reported teaching the genre than who reported receiving pedagogical training in the genre. Reported clinical voice observation hours were low (28.4% with ≥10 hours), and few respondents had >0 hours of operating room observation experience (11.8%). CONCLUSIONS: There is wide disparity across genres in the number of hours of observation and critical mentoring, and voice teachers' genre of instruction does not frequently match with the genre of pedagogical instruction they have received. More research is needed to determine the significance of this mismatch and whether increased hours of observation and mentoring would benefit voice instruction.