A Modest Flute Dispersal Test in the Age of Coronavirus

Irish Flute
1

I mentioned this in a thread over at thesession.org, but I thought this was a better venue for posting the results. I decided to try a very unscientific, ad-hoc test of how far and in what direction flute player breath travels. This of course, related to concerns about flute (and whistle) players being the only ones who can’t attend a session without wearing a mask. This is completely unscientific, just a quick check on my assumptions.

The test rig was a 3" x 6" strip of plastic wrap, taped to a mic stand, photo here:

http://ptjams.com/mb/img/flutes/Flute-Air-Test.jpg

NON-FLUTE TEST

Laughing as hard as I could, the strip stopped moving at 18" from my mouth.

A strong cough would still move the strip at 43" from my mouth.

FLUTE TEST

Playing the flute at my normal volume level, straight across from the embouchure stopped moving the indicator at 18", same as laughing.

However! Our airstream doesn’t travel straight across the embouchure hole, because we’re blowing slightly down, and there may be some laminar effects with the air that blows across the hole flowing around the flute barrel. In other words, the air that leaves the far side of the flute is aimed downward.

When I lowered the indicator 20" below the level of the flute, I could still move it just slightly from 26-30" away.

So my takeaway from this massively UNSCIENTIFIC test, and considering that we’re all different in how we blow the flute, is that flute players do move more air into the room than laughing. But a lot less than coughing, and the air we do move, is directed towards the floor and not across the room. Maybe some small comfort from other session players? I dunno.

P.S. I also tested whether I could move the indicator with any air leaving the bottom end of the flute, and it doesn’t. We’re not pushing air there. Drips, on the other hand… as usual, watch your Guiness and your left leg if you’re sitting to the right of a right-handed flute player.

2

Watch this: https://www.theverge.com/2020/4/17/21224815/talking-spit-watch-particles-mask-laser-droplets-visualization
And the watch this classic : https://www.businessinsider.com/video-japan-nhk-uv-light-how-virus-spread-restaurant-2020-5
Now, after you have taken these aboard, perhaps we can have a sensable discussion.
The force of your respiration is only a small part of the story when we are talking about aerosolubilsation of infective Virions. Ambient drafts are also a culprit. And this sets aside contact contamination as the NHK video shows.

Bob

3

I think the main problem arises from people laughing at you when playing the flute.

Have a great day!

[An interesting and imaginative test.]

4

:laughing:

Bob

5

A brief experiment suggests that a flute still works with a mask tied over the top of it. The mask doesn’t work properly because, obviously, it won’t seal. An oversize one with cuffs for the flute might be possible. But you would still be left with the low speed flow through the flute.

6

This article, form today’s Guardian/Observer deals mainly with the possible spread of the virus by singing, in it though a fluid mechanics expert is quoted who looked at musical instruments and how they dispersed aerosols and droplets:

And yes, one or two instruments did pose threats in terms of their powerful air flow and might spread virus particles dangerously if some form of protection was not added. In particular the flute is especially strong while the oboe and clarinet also posed problems. “The large wind instruments like the horn were not dangerous but the flute could be, it turned out. Its air flow is considerable.

7

It makes sense that the flute would be bad. A whistle too, I suppose.

And here I am working hard on breath pulsing and glottal stopping and huffing and puffing away. I have a feeling solo playing is my future

8

I’m aware of those factors, thanks. We can assume aerosol transmission – which is more like smoke than water droplets in an airstream – can travel much farther. Especially in dry air. This was really just intended as a fun starting point for thinking about transmission via flute, and to debunk the idea that flute-blown air isn’t any worse than laughing.

9

Perhaps we need to re-invent Florio’s flute curtain…

(Cornelius Ward is recounting, in his 1844 pamphlet, The Flute Explained. http://www.mcgee-flutes.com/Ward.htm#Contents )

“Twenty-five years after Quantz and Frederick the Great delighted themselves and the Court of Berlin, we find Florio using what were then called the extra keys, in the orchestra of the Italian opera in London; and he it was that placed or re-invented the keys for the low C# and C. He so prized this invention that he placed a small curtain upon the foot of his flute, to prevent the discovery of the means by which he produced these notes; and he further taught his daughter to make the keys, that the secret might be kept in his family. Soon after Florio’s time, Monzani commenced using a flute with the extra keys, but with the low C# only. We have in our possession the flute used by him for upwards of twenty years after this period, and which was the general flute within that time. Florio, Tacet, Collier, Hale, and the other manufacturers of the day, only occasionally making flutes with the C key. None of these makers seem to have been aware of the proper size and shape of the bore, or of the true position of the apertures.”

The Flute Curtain would of course only reduce transmission from the bottom end of the flute, which is probably our least problem. For the more dangerous top end of the flute, we might need to revive the Flute Beards discussion some time back…

10

A Flute Curtain, eh?

Along those lines… a friend has repurposed his manufacturing facility here in Washington state to make clear plastic face shields, distributing them free to local hospitals. He dropped off one at our house, just to show what it was like. I wonder if there’s room to tuck the flute inside the shield, and if it’s long enough to trap the downward flow?

OTOH that’s probably going to limit the volume others hear. And you might need earplugs yourself, from the reflected sound…

11

If we are trying to contain microscopic droplets from our possibly infected selves, a plastic face shield would seem to just divert the flow. Though you could be slowing it down. :smiley: The guys 6 feet in front of you may be spared. But someone behind you get a face full as in ricochets off the hard surface of the shield.

Face shields are good for protecting the wearer from direct hits from the front.

I think we just have to face it. In the new, hopefully temporary, world-- flute players and singers are the most likely spreaders.

12

You’re right, of course, although we’re all spreaders. We’re just having fun talking around the margins here. Everyone in a traditional tight-packed session where you can hear each other, and the fiddler to your right is about to jam the bow in your face, and the fluter on your left is dripping condensation on your leg, was the old normal.

Let’s all lift a glass of whatever we’re drinking at home in isolation as a mutual toast to fellow fluters, and hope for better times.