The airflow from a trained opera singer has been studied intensively. It led to this video, a year ago, and now to a published study (and a new video, too).
The study is “Tracking the Air Exhaled by an Opera Singer,” Philippe Bourrianne, Paul R. Kaneelil, Manouk Abkarian, and Howard A. Stone, Physical Review Fluids, vol. 6, no. 110503, 2021.
The researchers, at Princeton University and the University of Montpellier, report:
“We observed the air exhaled by a mezzosoprano singer during her performance of an Armenian lullaby “Oror.” We use a high-speed infrared camera (FLIR X6900SC) operating in the midwave range of the infrared spectrum (1.5–5 μm). The use of a filter in the absorption range of CO2 (4.2 μm) enables tracking the warm exhaled CO2. The opera singer sat beside a dark nonreflective curtain that provided a uniform background at the ambient temperature. As seen in the image sequence of Fig. 1, the infrared imaging captures the warm face of the singer and the warm exhaled CO2. The spatial extent of the exhaled CO2 can, thus, be estimated.”
There is an accompanying new video.