From classic to rap: Airborne transmission of different singing styles, with respect to risk assessment of a SARS-CoV-2 infection

1.Since the Covid-19 virus spreads through airborne transmission, questions concerning the risk of spreading infectious droplets during singing and music making has arisen. To contribute to this question and to help clarify the possible risks, we analyzed 15 singing scenarios (1) qualitatively - by making airflows visible, while singing - and (2) quantitatively - by measuring air velocities at three distances (1m, 1.5m and 2m). Air movements were considered positive when lying above 0.1 m/s, which is the usual room air velocity in venue, such as the concert hall of the Bamberg Symphony, where our measurements with three professional singers (female classical style, male classic style, female popular music style) took place. Our findings highlight that high measurements for respiratory air velocity while singing are comparable to measurements of speaking and - by far - less than coughing. All measurements for singing stayed within a reach of 1.5m, while only direct voiceless blowing achieved measurements at the 2m sensor. Singing styles that use plosive sounds, i.e. using consonants more often as in rap, produced the highest air velocities of 0.17 m/s at the 1m sensor. Also, singing while wearing a facemask produces no air movements over 0.1 m/s. On the basis of our recent studies on measurements of airflows and air velocities of professional singers and wind instrument players, as well as further studies on CO{square} measurements in room settings of music activities, we publish our results - in consideration of further up-to-date research - in our frequently updated risk assessment (first published in April 2020). On this behalf, we suggest 2m radial distances for singers, especially in choirs.