Language Log found a 2019 science paper that offers a different angle on airborne transmission of COVID-19.
Titled “Aerosol emission and superemission during human speech increase with voice loudness”, the paper comments on sneezing and coughing having a traditionally emphasised role in the airborne spread but speech is just as bad, if not worse when speech gets louder.
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 cm³) for low to high amplitudes, regardless of the language spoken (English, Spanish, Mandarin, or Arabic).
So don’t shout and bawl, but if you must, wear a mask while you do it.