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Cited by 919Infection Control and VentilationDental Research and COVID-19COVID-19 impact on air quality

Aerosol Emission and Superemission during Human Speech Increase with Voice Loudness

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Asadi, Sima, Wexler, Anthony S., Cappa, Christopher D., Barreda, Santiago, Bouvier, Nicole M., Ristenpart, William D.·2019·Scientific Reports
DOI 10.1038/s41598-019-38808-zPMC PMC6382806
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Abstract

Mechanistic hypotheses about airborne infectious disease transmission have traditionally emphasized the role of coughing and sneezing, which are dramatic expiratory events that yield both easily visible droplets and large quantities of particles too small to see by eye. Nonetheless, it has long been known that normal speech also yields large quantities of particles that are too small to see by eye, but are large enough to carry a variety of communicable respiratory pathogens. Here we show that the rate of particle emission during normal human speech is positively correlated with the loudness (amplitude) of vocalization, ranging from approximately 1 to 50 particles per second (0.06 to 3 particles per cm 3 ) for low to high amplitudes, regardless of the language spoken (English, Spanish, Mandarin, or Arabic). Furthermore, a small fraction of individuals behaves as “speech superemitters,” consistently releasing an order of magnitude more particles than their peers. Our data demonstrate that the phenomenon of speech superemission cannot be fully explained either by the phonic structures or the amplitude of the speech. These results suggest that other unknown physiological factors, varying dramatically among individuals, could affect the probability of respiratory infectious disease transmission, and also help explain the existence of superspreaders who are disproportionately responsible for outbreaks of airborne infectious disease.

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  • The simulated Gaussian distributions are consistent with Asadi et al.'s experimentally measured distribution for rate of particle generation speaking at a moderate volume, which for an extended size distribution comparable to ours (0.03 μm to 4.97 μm), would equate to ~19.6 particles/s.

    “This is consistent with Asadi et al.’s [9] experimentally measured distribution for rate of particle generation speaking at a moderate volume, which for an extended size distribution comparable to ours (0.03 μm to 4.97 μm), would equate to ~19.6 particles/s.”

    From The protective performance of reusable cloth face masks, disposable procedure masks, KN95 masks and N95 respirators: Filtration and total inward leakage (2021) · cites this paper as [9]

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  • Singing is another mode of particle production that is similar to speaking, but with consistently higher emission rates.

    “Singing is another mode of particle production that is similar to speaking, but with consistently higher emission rates [51].”

    From Comparative Mask Protection against Inhaling Wildfire Smoke, Allergenic Bioaerosols, and Infectious Particles (2022) · cites this paper as [51]

    The Introduction (page not provided) reports an earlier study finding six times more airborne droplet nuclei from singing than from normal talking. That supports a higher-output comparison, but the paper does not establish that singing has consistently higher particle emission rates across conditions; its own measurements concern speech, not singing. (LLM, conf=0.85)

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  • Normal physiological respiratory activities such as sneezing, coughing, talking and even breathing expel particles into the local environment.

    “The literature is replete with examples showing that normal physiological respiratory activities such as sneezing, coughing, talking and even breathing, expel particles into the local environment where individuals socialise and work [6–11].”

    From The protective performance of reusable cloth face masks, disposable procedure masks, KN95 masks and N95 respirators: Filtration and total inward leakage (2021) · cites this paper as [9]

  • The measured airborne bacteria size distributions are comparable to the range reported by Asadi et al. for speaking-generated particles.

    “comparable to the range reported by Asadi et al. [51] for speaking-generated particles.”

    From Comparative Mask Protection against Inhaling Wildfire Smoke, Allergenic Bioaerosols, and Infectious Particles (2022) · cites this paper as [51]

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Research works printed but not linked: 1

  1. [54]Saint-Exupéry, A. Le Petit Prince, trans Woods K (Harcourt, Brace & World, New York) 1st ed., Chapter 24 (1943).

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Authors
Asadi, S., Wexler, A. S., Cappa, C. D., Barreda, S., Bouvier, N. M., & Ristenpart, W. D.
Affiliations
  • University of California, Davis (US)
  • Icahn School of Medicine at Mount Sinai (US)
Corresponding author
Ristenpart, William D.
ORCID
Venue
Scientific Reports
Publisher
Springer Science and Business Media LLC
Published
2019-02-20
Volume
9
Issue
1
Pages
2348-2348
ISSN
2045-2322 (ISSN-L)
DOI
10.1038/s41598-019-38808-z
PMC
PMC6382806
OpenAlex
W2921493711
Cited by
919
References
61
Citations by year
2026: 35 · 2025: 49 · 2024: 60 · 2023: 105 · 2022: 175 · 2021: 275 · 2020: 218 · 2019: 2
FWCI
124.28
Type
journal article
Language
en
Open access
Licence
Locations
  • Scientific Reports (publishedVersion, cc-by)
  • Europe PMC (PubMed Central) (publishedVersion, other-oa)
  • PubMed Central (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion)
  • eScholarship (California Digital Library) (submittedVersion)
Funders
Division of Intramural Research, National Institute of Allergy and Infectious Diseases (R01 AI110703)
Topics
  • Health Sciences › Medicine › Pulmonary and Respiratory Medicine › Infection Control and Ventilation
  • Health Sciences › Dentistry › General Dentistry › Dental Research and COVID-19
  • Physical Sciences › Environmental Science › Global and Planetary Change › COVID-19 impact on air quality
Keywords
vocal intensity, airborne infectious disease transmission, respiratory pathogens, superspreaders, coughing and sneezing
MeSH terms
Adult, Aerosols, Cough, Female, Humans, Loudness Perception, Male, Particle Size, Sneezing, Speech, Disease Transmission, Infectious, Exhalation

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