[Lewis Thomson (OP)]

Frances has written in to ask,

"My almost 90 year old Mum has gone down with COVID. She lives in a care home and the three people that she shares a lunch table all went down with COVID, closely followed by Mum (who thankfully seems to have a mild version). One of the chaps who she has lunch with has a nasty habit of whistling and it set me to thinking could the virus be transmitted that way?"

What have you found? Leave your answers in the comments below...

[alancalverd]

There was a lot of fuss about choirs and brass bands a couple of years ago but the statistics have more to do with the concentration of sources and receptors than the production of sound. I play the tuba. It looks like a perfect COVID-cannon but in fact the exhaust velocity is very low: if I have to sustain a note for 15 seconds, that's only half a lungful of air and thus about the rate I would normally breathe out!

Whistling, on the other hand, does project a high velocity airstream, as does playing a flute, so although the volume of air will be the same, the stream doesn't disperse  as broadly as from a larger instrument - we are talking hose jet rather than fan - so you might project an infectious dose towards one victim rather than spread it relatively harmlessly among several.