Airflow and air velocity measurements while playing wind instruments, with respect to risk assessment of a SARS-CoV-2 infection

Spahn, C.; Hipp, A. M.; Schubert, B.; Axt, M. R.; Stratmann, M.; Schmoelder, C.; Richter, B.

Due to airborne transmission of infection with the coronavirus, the question arose as to how high the risk of spreading infectious particles can be while playing a wind instrument. To contribute to this question and to help clarify the possible risks, we analyzed 14 wind instruments, first qualitative by making airflows visible while playing and second quantitative by measuring air velocities at three distances (1m, 1.5m and 2m) in direction of the instruments bell. Measurements took place with wind instrumentalists of the Bamberg Symphony in their concert hall. Our findings highlight that while playing all wind instruments no airflow escaping from the instruments from the bell with brass instruments, from the mouthpiece, keyholes and bell with woodwinds was measured beyond a distance of 1.5m from the instruments bell, regardless of volume, pitch or what was played. With that, air velocity while playing corresponded to the usual value of hall-like rooms, of 0.1 m/s. For air-jet woodwinds, alto flute and piccolo, significant air movements were seen close to their mouthpieces, which escaped directly into the room without passing through the instrument and therefore generating directed air movements.