Air Flows in an Orchestra

Infectious respiratory diseases spread through the release of droplets carrying pathogens from an infected person. During the COVID-19 pandemic, clusters of contaminations were identified during rehearsals within a choir or an orchestra. Activities like singing or playing wind instruments are indeed accompanied by an enhanced release of droplets, carried by expiratory flows, and so are able to contaminate other musicians of an orchestra, or perhaps members of the audience. One should expect that opera performance is at higher risk of infection due to the large number of wind instruments, and the spectacular loudness of opera singers. By working with members of the MET Orchestra in New York City, we have tracked the air exhaled by individual professional performers using an infrared camera and other flow visualization techniques. We measure the expiratory flow-rates, the flow velocities and the spatial extent of the exhaled air during the performance, and compare them with breathing or speaking. By describing the air flows in opera, we isolate situations where air flows from musicians might increase the risk of contamination within an orchestra.