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Characterizing respiratory aerosol emissions during sustained phonation

Journal of Exposure Science & Environmental Epidemiology volume 32, pages 689–696 (2022)Cite this article

Abstract

Objective

To elucidate the role of phonation frequency (i.e., pitch) and intensity of speech on respiratory aerosol emissions during sustained phonations.

Methods

Respiratory aerosol emissions are measured in 40 (24 males and 16 females) healthy, non-trained singers phonating the phoneme /a/ at seven specific frequencies at varying vocal intensity levels.

Results

Increasing frequency of phonation was positively correlated with particle production (r = 0.28, p < 0.001). Particle production rate was also positively correlated (r = 0.37, p < 0.001) with the vocal intensity of phonation, confirming previously reported findings. The primary mode (particle diameter ~0.6 μm) and width of the particle number size distribution were independent of frequency and vocal intensity. Regression models of the particle production rate using frequency, vocal intensity, and the individual subject as predictor variables only produced goodness of fit of adjusted R2 = 40% (p < 0.001). Finally, it is proposed that superemitters be defined as statistical outliers, which resulted in the identification of one superemitter in the sample of 40 participants.

Significance

The results suggest there remain unexplored effects (e.g., biomechanical, environmental, behavioral, etc.) that contribute to the high variability in respiratory particle production rates, which ranged from 0.2 particles/s to 142 particles/s across all trials. This is evidenced as well by changes in the distribution of participant particle production that transitions to a more bimodal distribution (second mode at particle diameter ~2 μm) at higher frequencies and vocal intensity levels.

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Fig. 1: Examples of audio and aerosol recordings.
Fig. 2: Variation in vocal intensity and frequency for all of the subjects.
Fig. 3
Fig. 4: Aerosol emissions as a function of frequency.
Fig. 5: Correlation plots with Pearson correlation value (r) and p value for particle production.
Fig. 6: Density plots of particle production rates for categories of frequency and vocal intensity (ARMS) subdivided by 20th percentiles.

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References

  1. Scully C, Samaranayake L. Emerging and changing viral diseases in the new millennium. Oral Dis. 2016;22:171–9. https://doi.org/10.1111/odi.12356.

    Article  CAS  PubMed  Google Scholar 

  2. Wei J, Li Y. Airborne spread of infectious agents in the indoor environment. Am J Infect Control. 2016;44:S102–8.

  3. Miller SL, Nazaroff WN, Jimenez JL, Boerstra A, Buonanno G, Dancer SJ, et al. Transmission of SARS-CoV-2 by inhalation of respiratory aerosol in the Skagit Valley Chorale superspreading event. Indoor Air. 2021;31:314–23.

  4. COVID live update: 227,120,892 cases and 4,670,845 deaths from the Coronavirus—Worldometer. Dover, Delaware, USA. 2021. https://www.worldometers.info/coronavirus/#countries.

  5. Ozbay G, Sariisik M, Ceylan V, Çakmak M. A comparative evaluation between the impact of previous outbreaks and COVID-19 on the tourism industry. Int Hosp Rev. 2021. https://doi.org/10.1108/IHR-05-2020-0015.

  6. Wang CC, Prather KA, Snitzman J, Jimenez JL, Lakdawala SS, Tufekci Z, et al. Airborne transmission of respiratory viruses. Science. 2021;373. https://doi.org/10.1126/science.abd9149.

  7. Parienta D, Morawska L, Johnson GR, Ristovski ZD, Hargreaves M, Mengersen K, et al. Theoretical analysis of the motion and evaporation of exhaled respiratory droplets of mixed composition. J Aerosol Sci. 2011;42:1–10.

  8. Morawska L, Cao J. Airborne transmission of SARS-CoV-2: the world should face the reality. Environ Int. 2020;139:105730. https://doi.org/10.1016/j.envint.2020.105730.

  9. Fennelly KP. Particle sizes of infectious aerosols: implications for infection control. Lancet Respir Med. 2020;8:914–24. https://doi.org/10.1016/S2213-2600(20)30323-4.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  10. Alsved M, Matamis A, Bohlin R, Richter M, Bengtsson P-E, Fraenkel C-J, et al. Exhaled respiratory particles during singing and talking. Aerosol Sci Technol. 2020;54:1245–8.

  11. Asadi S, Wexler AS, Cappa CD, Barreda S, Bouvier NM, Ristenpart WD. Aerosol emission and superemission during human speech increase with voice loudness. Sci Rep. 2019;9:2348.

  12. Johnson GR, Morawska L, Ristovski ZD, Hargreaves M, Mengersen K, Chao CYH, et al. Modality of human expired aerosol size distributions. J Aerosol Sci. 2011;42:839–51. https://doi.org/10.1016/j.jaerosci.2011.07.009.

    Article  CAS  Google Scholar 

  13. Stadnytskyi V, Bax CE, Bax A, Anfinrud P. The airborne lifetime of small speech droplets and their potential importance in SARS-CoV-2 transmission. Proc Natl Acad Sci USA. 2020;117:11875–7.

  14. Lednicky JA, Lauzardo M, Hugh Fan Z, Jutla A, Tilly TB, Gangwar M, et al. Viable SARS-CoV-2 in the air of a hospital room with COVID-19 patients. Int J Infect Dis. 2020;100:476–82. https://doi.org/10.1016/j.ijid.2020.09.025.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  15. Ho CK. Modeling airborne pathogen transport and transmission risks of SARS-CoV-2. Appl Math Model. 2021;95:297–319.

    Article  PubMed  PubMed Central  Google Scholar 

  16. Tellier R, Li Y, Cowling BJ, Tang JW. Recognition of aerosol transmission of infectious agents: a commentary. BMC Infect Dis. 2019;19:101. https://doi.org/10.1186/s12879-019-3707-y.

  17. Tan ZP, Silwal L, Bhatt SP, Raghav V. Experimental characterization of speech aerosol dispersion dynamics. Sci Rep. 2021;11:3953. https://doi.org/10.1038/s41598-021-83298-7.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  18. Furuse Y, Sando E, Tsuchiya N, Miyahara R, Yasuda I, Ko YK, et al. Clusters of Coronavirus Disease in communities, Japan, January–April 2020. Emerg Infect Dis. 2020;26:2176–9. https://doi.org/10.3201/eid2609.202272.

    Article  CAS  PubMed Central  Google Scholar 

  19. Gregson FKA, Watson NA, Orton CM, Haddrell AE, McCarthy LP, Finnie TJR, et al. Comparing aerosol concentrations and particle size distributions generated by singing, speaking and breathing. Aerosol Sci Technol. 2021;55: 681–91.

  20. Johnson GR, Morawska L. The mechanism of breath aerosol formation. J Aerosol Med Pulm Drug Deliv. 2009;22:229–37.

  21. Mittal R, Erath BD, Plesniak MW. Fluid dynamics of human phonation and speech. Annu Rev Fluid Mech. 2013;45:437–67. https://doi.org/10.1146/annurev-fluid-011212-140636.

    Article  Google Scholar 

  22. Mürbe D, Kriegel M, Lange J, Schumann L, Hartmann A, Fleischer M. Aerosol emission of adolescents voices during speaking, singing and shouting. PLoS ONE. 2021;16:e0246819. https://doi.org/10.1371/journal.pone.0246819.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  23. Asadi S, Wexler AS, Cappa CD, Barreda S, Bouvier NM, Ristenpart WD. Effect of voicing and articulation manner on aerosol particle emission during human speech. PLoS ONE. 2020;15:e0227699. https://doi.org/10.1371/journal.pone.0227699.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  24. Mürbe D, Fleischer M, Lange J, Rotheudt H, Kriegel M. Aerosol emission is increased in professional singing. 2020.

  25. Lloyd-Smith JO, Schreiber SJ, Kopp PE, Getz WM. Superspreading and the effect of individual variation on disease emergence. Nature. 2005;438:355–9. https://doi.org/10.1038/nature04153.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  26. Stein RA. Super-spreaders in infectious diseases. Int J Infect Dis. 2011;15:e510–3. https://doi.org/10.1016/j.ijid.2010.06.020.

    Article  PubMed  PubMed Central  Google Scholar 

  27. Chaudhury NMA, Shirlaw P, Pramanik R, Carpenter GH, Proctor GB. Changes in saliva rheological properties and mucin glycosylation in dry mouth. J Dent Res. 2015;94:1660–7.

    Article  CAS  PubMed  Google Scholar 

  28. Mofakham AA, Helenbrook BT, Erath BD, Ferro AR, Ahmed T, Brown DM, et al. On the variation of fricative airflow dynamics with vocal tract geometry and speech loudness. Aerosol Sci Technol. 2022:1–24. https://doi.org/10.1080/02786826.2022.2045001.

  29. Echternach M, Burk F, Burdumy M, Traser L, Richter B. Morphometric differences of vocal tract articulators in different loudness conditions in singing. PLoS ONE. 2016;11:e0153792. https://doi.org/10.1371/journal.pone.0153792.

  30. Ahmed T, Wendling HE, Mofakham AA, Ahmadi G, Helenbrook BT, Ferro AR, et al. Variability in expiratory trajectory angles during consonant production by one human subject and from a physical mouth model: application to respiratory droplet emission. Indoor Air. 2021;31:1896–912. https://doi.org/10.1111/ina.12908.

    Article  PubMed  PubMed Central  Google Scholar 

  31. Morawska L, Johnson GR, Ristovski ZD, Hargreaves M, Mengersen K, Corbett S, et al. Size distribution and sites of origin of droplets expelled from the human respiratory tract during expiratory activities. J Aerosol Sci. 2009;40:256–69.

  32. Malashenko A, Tsuda A, Haber S. Propagation and breakup of liquid menisci and aerosol generation in small airways. J Aerosol Med Pulm Drug Deliv. 2009;22:341–53. https://doi.org/10.1089/jamp.2008.0696.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  33. Titze IR, Martin DW. Principles of voice production. J Acoust Soc Am. 1998;104:1148. https://doi.org/10.1121/1.424266.

    Article  Google Scholar 

  34. Protopapas A, Lieberman P. Fundamental frequency of phonation and perceived emotional stress. J Acoust Soc Am. 1997;101:2267–77. https://doi.org/10.1121/1.418247.

    Article  CAS  PubMed  Google Scholar 

  35. Jacewicz E, Fox RA. Intrinsic fundamental frequency of vowels is moderated by regional dialect. J Acoust Soc Am. 2015;138:EL405–10. https://doi.org/10.1121/1.4934178.

    Article  PubMed  PubMed Central  Google Scholar 

  36. Gramming P, Sundberg J, Ternström S, Leanderson R, Perkins WH. Relationship between changes in voice pitch and loudness. J Voice. 1988;2:118–26.

  37. von der Weiden S-L, Drewnick F, Borrmann S. Particle loss calculator—a new software tool for the assessment of the performance of aerosol inlet systems. Atmos Meas Tech. 2009;2:479–94. https://doi.org/10.5194/amt-2-479-2009.

    Article  Google Scholar 

  38. Ghorbani H. Mahalanobis distance and its application for detecting multivariate outliers. Facta Univ Ser Math Inform. 2019:583. https://doi.org/10.22190/FUMI1903583G.

  39. Cohen P, Cohen P, West SG, Aiken LS. Applied multiple regression/correlation analysis for the behavioral sciences. 0 ed. Psychology Press; New York. 2014. https://doi.org/10.4324/9781410606266.

  40. Verkerke GJ, Thomson SL. Sound-producing voice prostheses: 150 years of research. Annu Rev Biomed Eng. 2014;16:215–45. https://doi.org/10.1146/annurev-bioeng-071811-150014.

    Article  CAS  PubMed  Google Scholar 

  41. Li Y, Sprittles JE. Capillary breakup of a liquid bridge: identifying regimes and transitions. J Fluid Mech. 2016;797:29–59.

    Article  CAS  Google Scholar 

  42. Bhat PP, Appathurai S, Harris MT, Pasquali M, McKinley GH, Basaran OA. Formation of beads-on-a-string structures during break-up of viscoelastic filaments. Nat Phys. 2010;6:625–31. https://doi.org/10.1038/nphys1682.

    Article  CAS  Google Scholar 

  43. Veron F. Ocean spray. Annu Rev Fluid Mech. 2015;47:507–38. https://doi.org/10.1146/annurev-fluid-010814-014651.

    Article  Google Scholar 

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Acknowledgements

Special thanks to Mehtap Agirsoy for her assistance with data collection.

Funding

This work was supported by the National Science Foundation [CBET:2029548].

Author information

Authors and Affiliations

  1. Department of Mechanical and Aerospace Engineering, Clarkson University, Potsdam, NY, 13699, USA

    Tanvir Ahmed, Amir A. Mofakham, Brian T. Helenbrook, Goodarz Ahmadi & Byron D. Erath

  2. Department of Civil and Environmental Engineering, Clarkson University, Potsdam, NY, 13699, USA

    Mahender Singh Rawat & Andrea R. Ferro

  3. Department of Mathematics, Clarkson University, Potsdam, NY, 13699, USA

    Dinushani Senarathna & Sumona Mondal

  4. Joint Educational Programs, Trudeau Institute, Saranac Lake, NY, 12983, USA

    Deborah Brown

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Contributions

TA designed and performed the aerosol experiments and wrote the manuscript. MSR designed and performed the aerosol experiments and wrote the manuscript. ARF designed the aerosol experiments, provided advisement, and helped write the manuscript. AAM helped design the experiments and write the manuscript. BTH helped design the experiment, provided advisement, and helped write the manuscript. GA helped design the experiment, provided advisement, and helped write the manuscript. DS performed the statistical analysis and wrote the manuscript. SM performed the statistical analysis, provided advisement, and wrote the manuscript. DB helped design the experiment, and helped write the manuscript. BDE designed the aerosol experiments, provided advisement and project administration, and helped write the manuscript.

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Correspondence to Byron D. Erath.

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Ahmed, T., Rawat, M.S., Ferro, A.R. et al. Characterizing respiratory aerosol emissions during sustained phonation. J Expo Sci Environ Epidemiol 32, 689–696 (2022). https://doi.org/10.1038/s41370-022-00430-z

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